精妙SQL语句收集
sql 高级语句
sql 高级语句1. 哎呀,你知道吗?SQL 高级语句就像是一把神奇的钥匙,能打开数据库的神秘宝藏!比如说,当你想从海量数据中快速筛选出特定条件的数据,像从一堆糖果中挑出你最爱的口味,用 `WHERE` 子句就能轻松搞定!你难道不想拥有这样的神奇能力?2. 嘿,朋友!SQL 高级语句简直是数据分析的超级武器!就好比你在战场上,有了它就能精准打击目标。
像 `JOIN` 操作,能把不同表的信息整合起来,这不就像把拼图碎片拼成完整的画面吗?你不想试试?3. 哇塞!SQL 高级语句可太牛啦!它就像一个魔法棒,能让数据乖乖听话。
比如说 `GROUP BY` 语句,能把数据分组统计,这难道不像把一群小伙伴按照特点分类吗?是不是很神奇?4. 亲,SQL 高级语句那可是高手必备的技能!比如说 `HAVING` 子句,它能在分组后进行筛选,这感觉就像在一堆整理好的物品中再挑出精品,你难道不心动?5. 哎呀呀,SQL 高级语句简直是数据世界的主宰!像 `ORDER BY` 能让数据按你想要的顺序排列,这不就跟给调皮的孩子排好队一样简单吗?你还不赶紧掌握?6. 嘿!SQL 高级语句可是个大宝贝!比如说`SUBQUERY` 子查询,能在一个查询中嵌套另一个查询,这就像在一个大盒子里装着小盒子,充满惊喜!难道你不好奇?7. 哇哦!SQL 高级语句厉害得不要不要的!比如 `UNION` 操作,能把多个查询结果合并,这难道不像把几条小溪汇聚成一条大河?你不想试试看?8. 亲呐,SQL 高级语句就是通往数据巅峰的捷径!像 `DISTINCT` 关键字,能去除重复数据,这感觉就像把杂物清理掉只留下精华,是不是很棒?9. 哎呀,SQL 高级语句太让人惊叹了!比如说 `INDEX` 索引,能大大提高查询速度,这就像给你的赛车装上超强引擎,难道不酷?10. 嘿哟,SQL 高级语句简直是无敌的存在!像 `CASE WHEN` 语句,能实现灵活的条件判断,这不就跟你在做复杂的选择题时有了标准答案一样吗?你还在等什么?11. 哇噻!SQL 高级语句可真是妙不可言!比如说 `LIMIT` 限制行数,能只获取你需要的部分数据,这难道不像在一大桌美食中只挑你最想吃的那几样?是不是很实用?12. 亲呀,SQL 高级语句那是相当厉害!比如 `OFFSET` 偏移量,能跳过一些数据开始获取,这感觉就像在一本书中跳过前面的章节直接从中间开始读,你不想体验下?13. 哎呀妈呀,SQL 高级语句太牛掰了!像 `CTE` 公共表表达式,能把复杂的查询分解成多个部分,这难道不像把一个大任务分解成小步骤逐个完成?是不是很聪明?14. 嘿,SQL 高级语句绝对是数据处理的神器!比如说`ROW_NUMBER` 函数,能给每行数据编号,这就像给每个士兵都贴上了专属标签,难道不厉害?15. 哇啦哇啦,SQL 高级语句厉害炸了!比如`PIVOT` 行转列操作,能把数据的结构进行转换,这难道不像给房子重新装修换个风格?你不想尝试下?16. 亲哟,SQL 高级语句那可是神一般的存在!像 `MERGE` 合并操作,能根据条件更新或插入数据,这感觉就像给两个团队合并并安排好每个人的位置,是不是很强大?17. 哎呀喂,SQL 高级语句太让人佩服了!比如说 `WINDOW FUNCTIONS` 窗口函数,能对数据进行分区计算,这难道不像把一个大蛋糕切成小块分别计算?是不是很有趣?18. 嘿呀,SQL 高级语句简直绝绝子!像 `CROSS APPLY` 和`OUTER APPLY` ,能关联表并获取相关数据,这就像两个好朋友手牵手分享彼此的秘密,难道不吸引人?19. 哇哈哈,SQL 高级语句太厉害了吧!比如说 `XML and JSON functions` ,能处理 XML 和 JSON 格式的数据,这难道不像拥有了能读懂各种语言的超能力?你不想拥有吗?20. 亲呐亲,SQL 高级语句就是数据世界的王者!像 `Full-text Search` 全文搜索,能快速找到你想要的文本,这感觉就像在茫茫书海中瞬间找到你渴望的那一页,是不是超棒?。
精妙SQL语句介绍(大全)
SQL:select top 10 * from temp where id not in (select top 30 id from temp order by id asc) order by id asc
说明:复制表(只复制结构,源表名:a 新表名:b)
--5、在销售明细表中按产品编号进行汇总,统计每种产品的销售数量和金额 select prod_id,sum(qty) totqty,sum(qty*unit_price) totprice from sale_item group by prod_id
--6、使用convert函数按客户编号统计每个客户1996年的订单总金额 select cust_id,sum(tot_amt) totprice from sales where convert(char(4),order_date,120)=’1996’ group by cust_id
2、查找与喻自强在同一个单位的员工姓名、性别、部门和职称 select emp_no,emp_name,dept,title from employee where emp_name<>’喻自强’ and dept in (select dept from employee where emp_name=’喻自强’)
-1、查找员工的编号、姓名、部门和出生日期,如果出生日期为空值, --显示日期不详,并按部门排序输出,日期格式为yyyy-mm-dd。 select emp_no ,emp_name ,dept , isnull(convert(char(10),birthday,120),’日期不详’) birthday from employee order by dept --
SQL语句 大全
一、基础1、说明:创建数据库CREATE DATABASE database-name2、说明:删除数据库drop database dbname3、说明:备份sql server--- 创建备份数据的 deviceUSE masterEXEC sp_addumpdevice 'disk', 'testBack','c:\mssql7backup\MyNwind_1.dat'--- 开始备份BACKUP DATABASE pubs TO testBack4、说明:创建新表create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)根据已有的表创建新表:A:create table tab_new like tab_old (使用旧表创建新表)B:create table tab_new as select col1,col2… from tab_old definition only5、说明:删除新表drop table tabname6、说明:增加一个列Alter table tabname add column col type注:列增加后将不能删除。
DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。
7、说明:添加主键:Alter table tabname add primary key(col) 说明:删除主键: Alter table tabname drop primary key(col) 8、说明:创建索引:create [unique] index idxname ontabname(col….)删除索引:drop index idxname注:索引是不可更改的,想更改必须删除重新建。
9、说明:创建视图:create view viewname as select statement删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select * from table1 where 范围插入:insert into table1(field1,field2) values(value1,value2) 删除:delete from table1 where 范围更新:update table1 set field1=value1 where 范围查找:select * from table1 where field1 like ’%value1%’ ---like 的语法很精妙,查资料!排序:select * from table1 order by field1,field2 [desc]总数:select count as totalcount from table1求和:select sum(field1) as sumvalue from table1 平均:select avg(field1) as avgvalue from table1最大:select max(field1) as maxvalue from table1最小:select min(field1) as minvalue from table111、说明:几个高级查询运算词A:UNION 运算符UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。
语录 经典SQL语句
语录大全经典SQL语句大全1(仅用于SQlServer)法二:select top 0 * into b from a2、说明:拷贝表(拷贝数据,源表名:a目标表名:b) (Access可用)insert into b(a, b, c) select d,e,f from b;3、说明:跨数据库之间表的拷贝(详细数据使用肯定路径) (Access 可用)insert into b(a, b, c) select d,e,f from b in ‘详细数据库’ where条件例子:..from b in " where..4、说明:子查询(表名1:a表名2:b)select a,b,c from a where a IN (select d from b )或者: select a,b,c from a where a IN (1,2,3)5、说明:显示文章、提交人和最终回复时间selecta.title,ername,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b6、说明:外连接查询(表名1:a表名2:b)select a.a, a.b, a.c, b.c,b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c7、说明:在线视图查询(表名1:a )select * from (SELECT a,b,c FROMa) T where t.a > 1;8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括select * from table1 where time between time1 and time2select a,b,c, from table1 where a not between数值1 and 数值29、说明:in的使用方法select * from tabl e1 where a [not] in (‘值1’,’值2’,’值4’,’值6’)10、说明:两张关联表,删除主表中已经在副表中没有的信息delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )11、说明:四表联查问题:select * from a left inner join b ona.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where.....12、说明:日程支配提前五分钟提示SQL: select * from日程支配where datediff(minute,f开头时间,getdate())>513、说明:一条sql语句搞定数据库分页select top 10 b.* from (select top 20主键字段,排序字段from表名order by排序字段desc) a,表名b where b.主键字段= a.主键字段order by a.排序字段详细实现:关于数据库分页:declare @start int,@end int@sqlnvarchar(600)set @sql=’select top’+str(@end-@start+1)+’+from T where rid not in(select top’+str(@str-1)+’Rid from T where Rid>-1)’exec sp_executesql @sql留意:在top后不能直接跟一个变量,所以在实际应用中只有这样的进行特别的处理。
sql经典语句(SQLclassicsentences)
sql经典语句(SQL classic sentences)I. Basic operation1) DESC, the describe role is to display the structure of the data table using the form: desc data table name2) distinct eliminates duplicate data usage: select, distinct, field name, from data table3) order by field 1 ASC, field 2 desc4) nested queries select, emp.empno, emp.ename, emp.job, emp.salFrom scott.empWhere sal>= (select, Sal, from, scott.emp, where, ename='WARD');5) nested queries select, emp.empno, emp.ename, emp.job, in, emp.salFrom scott.empWhere, Sal, in (select, Sal, from, scott.emp, where, ename ='WARD');6) nested queries select, emp.empno, emp.ename, emp.job, any, emp.salFrom scott.empWhere Sal > any (select, Sal, from, scott.emp, where, job='MANAGER');Equivalent to (1) select, Sal, from, scott.emp, where, job ='MANAGER'(2) select, emp.empno, emp.ename, emp.job, emp.salFrom scott.empData found in where Sal > (1) data a, or, Sal > (1), data found in B, or, Sal > (1), CEg:Select, Sal, from, scott.emp, where, job ='MANAGER'results; 12,10,13Equivalent to sal=12,10,13 or SAL> (12, OR, 10, OR, 13)7) the intersection operation is the intersection concept in the set. The sum of the elements that belong to the set A and belongs to the set B is the intersection. In the command edit area, execute the following statement.Eg:(select, djbh, from, ck_rwd_hz) intersect (select, djbh, from, ck_rwd_mx) documents numbered the sameSelect * from ck_rwd_mx a,((select, djbh, from, ck_rwd_hz) intersect (select, djbh, from, ck_rwd_mx)) BWhere a.djbh =b.djbhTwo function1) ceil takes the minimum integer ceil (N) greater than or equal to the value N; select, Mgr, mgr/100, ceil (mgr/100), from, scott.emp;2) floor takes the maximum integer floor (N) less than or equal to the value N; select, Mgr, mgr/100, floor (mgr/100), from, scott.emp;3) the remainder of mod m divisible by mod (m, n) n4) power, m, N, square, mod (m, n)5) round m four, five, keep the n bit mod (m, n)Select round (8.655,2) from dual; 8.66Select round (8.653,2) from dual; 8.656) sign n>0, take 1; n=0, take 0; n<0, take -1;7) AVG averages AVG (field name)8) count statistics total count (field name) select (*) from scott.emp; select count (distinct job) from scott.emp;9) min calculates numeric fields minimum, select, min (SAL), minimum salary from scott.emp;10) max calculates numeric field maximum, select, max (SAL), highest salary from scott.emp;11) sum calculates the sum of numeric fields, select, sum (SAL), the sum of salaries, from, scott.emp;Three input data1) single data entryInsert into data tables (fields 1, fields 2,...) valuse (field name 1 values, field name 2 values,...)Numeric fields can write values directly; character fields add single quotation marks; date fields add single quotes; at the same time pay attention to the order of days and months2) multi line data entryInsert into data table (field name 1, field name 2,...)(select (field name 1 or operation, field name 2 or operation,...) from data table where condition)3) data replication between tablesCreate table scott.testAs(Select, distinct, empno, ename, hiredate, from, scott.emp, where, empno>=7000);Create table spkpk_liu as select * from spkfk; creates tables and copies data, but creates incomplete table informationThis is all the way to full table backups.Usually after the table is built, you need to see if you want to build the index and primary key again.And "create, table, spkpk_liu, as, select * from, spkfk.""After this table is built, many of the parameter values of the table are the default minimum values, such as the initial value of the original table 10M, and the new table is probably only 256K.Formal environment used in the table, generally do not recommend such a table built.In this way, just a little lazy, if you do so,A statement can achieve the purpose of building tables and inserting data.For example, you need to modify the data in table A, and you might want to back up the data from the A table before you modify it.This time you can use create table... As...This makes it easy to retrieve data from the A table in the futureYou can do this when you debug your own program, but you can't create processes, packages, functions like thisFour delete dataDelete deletes data; truncate deletes the entire table data, but retains the structure1) delete recordsDelete from scott.test where empno and empno <=8000 > = 7500;2) delete the entire dataTruncate table scott.test;Similarities and differences between truncate, delete and dropNote: the delete here refers to the delete statement without the where clauseThe same thing: truncate and the delete without the where clause, and drop will delete the data in the tableDifference:1. truncate and delete only delete data and do not delete the structure of the table (definition)The drop statement will delete the structure of the table, the dependent constraints (constrain), the trigger, and the index (index); the stored procedure / function that depends on the table will be retained, but the invalid state will be changedThe 2.delete statement is DML, which is put into the rollback segement before the transaction is committed, and if you have the corresponding trigger, the execution will be triggeredTruncate, drop is DDL, the operation takes effect immediately, and the original data is not put into the rollback segment and cannot be rolled back. The operation does not trigger trigger.. Obviously, the drop statement releases all the space occupied by the table3. speed, in general: drop>, truncate > deleteOn use, you want to delete part of the data rows, with delete,take care to bring the where clause. The rollback section is large enough to be rolled back through the ROBACK, and there is considerable room for recoveryTo delete tables, of course, use dropYou want to keep the table and delete all the data. If you have nothing to do with the transaction, you can use truncate. Truncate, table, XX, delete the entire table of data, there is no room for recovery, the benefits can be arranged in the table debris, release spaceSo it's better to back up the data firstIf you are tidying up the inner fragments of a table, you can use truncate to catch up with reuse stroage and then import / insert data againFive update dataUpdate data sheetSet field name, 1=, new assignment, field name, 2=, new assignment,...Where conditionUpdate scott.empSet, empno=8888, ename='TOM', hiredate='03-9, -2002'Where empno = 7566;Update scott.empSet sal=(select, sal+300, from, scott.emp, where, empno = 8099)Where empno=8099;Decode (condition, value 1, translation value 1, value 2, translation value 2, value n, translation value n, default value)Six data export1 export the database TEST completely, export the user name system password manager to D:\daochu.dmpExpsystem/manager@TESTfile=d:\daochu.dmp full=y2 export the system user in the database to the table of the sys userExpsystem/manager@TESTfile=d:\daochu.dmp only wner= (system, Sys)3 export tables table1 and table2 from the databaseExpsystem/manager@TESTfile=d:\daochu.dmp tables= (table1, table2)4 export the field filed1 in the table table1 in the database to data that starts with "00"Expsystem/manager@TESTfile=d:\daochu.dmp tables= (table1) query=\ "where filed1 like'00%'\""Explmis_wh/lmis@lmisbuffer=10000 only WNER=lmis_wh rows=nfile=d:\lmis_wh_nodata.dmp log=d:\lmis_wh_nodata.logImplmis/lmis@lmisbuffer=10000, fromuser=lmis_wh, touser=lmis, file=d:\lmis_wh_nodata.dmp, log=d:\lmis_wh_nodata.logC:\>implmis/lmis@lmisbuffer=50000000, full=n,file=e:\daochu.dmp, ignore=y, rows=yCommit=y compile=y fromuser=lmis_wh touser=lmisSeven data import1 import data from the D:\daochu.dmp into the TEST database.Impsystem/manager@TEST file=d:\daochu.dmpThere may be a problem with it because some tables already exist, and then it is reported wrong, and the table is not imported.It's OK to add ignore=y at the back.2 import table table1 from d:\daochu.dmpImpsystem/manager@TEST file=d:\daochu.dmp tables= (table1)SQL definition: SQL is a database oriented general data processing language specification, can complete the following functions: data extraction query, insert modify delete data generation, modify and delete database objects, database security, database integrity control and data protection.SQL classification:DDL - Data Definition Language (CREATE, ALTER, DROP, DECLARE)DML - Data Manipulation Language (SELECT, DELETE, UPDATE, INSERT)DCL - data control language (GRANT, REVOKE, COMMIT, ROLLBACK) DDL - database definition language: direct submission. CREATE: used to create database objects.DECLARE: in addition to creating temporary tables that are used only during the process, the DECLARE statements are very similar to the CREATE statements. The only object that can be declared is the table. And must be added to the user temporary tablespace.DROP: you can delete any object created with CREATE (database object) and DECLARE (table).ALTER: allows you to modify information about certain databaseobjects. Cannot modify index.Eight, the following is mainly based on object presentation of basic grammar1, database:Create database: CREATE, DATABASE, database-name, [USING, CODESET, codeset, TERRITORY, territory]Note: the code page problem.Delete database: drop, database, dbname2, table:Create new table:Create, table, tabname (col1, Type1, [not, null], [primary, key], col2, type2, [not, null],...)Create a new table based on the existing table:A:create, table, tab_new, like, tab_oldB:create, table, tab_new, as, select, col1, col2... From tab_old definition onlyModify table:Add a column:Alter, table, tabname, add, column, col, typeNote: column added will not be deleted. The DB2 column after the data type does not change, the only change is to increase the size of the varchar. Add primary key:Alter, table, tabname, add, primary, key (Col)Delete Primary key:Alter, table, tabname, drop, primary, key (Col)Delete table: drop, table, tabnameAlter table BMDOC_LIUFDrop constraint PK1_BMDOC cascade;3, table space:Create table spaces: create, tablespace, tbsname, PageSize, 4K, managed, by, database, using (file, file, size)Adding containers to tablespace: alter, tablespace, tablespace_name, add (file,'filename', size)Note: the operation is irreversible and will not be removed after adding the container. Therefore, when it is added, pay attention to it.Delete tablespace: drop, tablespace, tbsname4, index:Create indexes: create, [unique], index, idxname, on, tabname (col... ).Delete index: drop, index, idxnameNote: the index is not modifiable. If you want to change it, you must delete it.5 views:Create views: create, view, VIEWNAME, as, select, statementDelete view: drop view VIEWNAMENote: the only change to the view is the reference type column, which changes the range of columns. None of the other definitions can be modified. The view becomes invalid when the view is based on the base table drop.DML - the database manipulation language, which does not implicitly submit the current transaction and is committed to the setting of the visual environment.SELECT: querying data from tablesNote: the connection in the condition avoids Cartesian productDELETE: delete data from existing tablesUPDATE: update data for existing tablesINSERT: insert data into existing tablesNote: whether DELETE, UPDATE, and INSERT are submitted directly depends on the environment in which the statement is executed.Pay attention to the full transaction log when executing.2, DELETE: delete records from the tableSyntax format:DELETE, FROM, tablename, WHERE (conditions)3, INSERT: insert a record into the tableSyntax format:INSERT INTO tablename (col1, col2),... ) VALUES (value1, Value2),... );INSERT INTO tablename (col1, col2),... ) VALUES (value1, Value2),... ) (value1, value2,... ),......Insert does not wait for any program and does not cause locking4, UPDATE:Syntax format:UPDATE tabname SET (col1=values1, col2=values2),... (WHERE) (conditions);Note: update is slower and requires indexing on the corresponding column.Nine permissionsDCL - Data Control LanguageGRANT - Grant user permissionsREVOKE - revoke user rightsCOMMIT - commit transactions can permanently modify the databaseROLLBACK - rollback transactions, eliminating all changes made after the last COMMIT command, so that the contents of the database are restored to the state after the last COMMIT execution.1, GRANT: all or administrators assign access rights to other usersSyntax format:Grant [all privileges|privileges,... On tabname VIEWNAME to [public|user |,... .2 and REVOKE: cancel one of the user's access rightsSyntax format:Revoke [all privileges|privileges,... On tabname VIEWNAME from [public|user |,... .Note: any permissions of users of instance level cannot be canceled. They are not authorized by grant, but are permissions implemented by groups.3, COMMIT: permanently records changes made in the transaction to the database.Syntax format:Commit [work]4, ROLLBACK: will undo all changes made since the last submission.Syntax format:Rollback [work]Ten advanced SQL brief introductionFirst, the query between the use of computing wordsA:UNION operatorThe UNION operator derives a result table by combining two other result tables (such as TABLE1 and TABLE2) and eliminating any duplicate rows in the table.When ALL is used with UNION (that is, UNION ALL), the duplicate rows are not eliminated. In the two case, each row of the derived table does not come from TABLE1, or from TABLE2.B:EXCEPT operatorThe EXCEPT operator derives a result table by including all rows in TABLE1, but not in TABLE2, and eliminating all duplicate rows. When ALL is used with EXCEPT (EXCEPT ALL), the duplicate rows are not eliminated.C:INTERSECT operatorThe INTERSECT operator derives a result table by including only rows in TABLE1 and TABLE2 and eliminating all duplicate rows. When ALL is used with INTERSECT (INTERSECT ALL), the duplicate rows are not eliminated.Note: several query results lines using arithmetic words must be consistent.Appendix: introduction to commonly used functions1, type conversion function:Converted to a numeric type:Decimal, double, Integer, smallint, realHex (ARG): 16 hexadecimal representation converted into parameters.Converted to string type:Char, varcharDigits (ARG): returns the string representation of Arg, and Arg must be decimal.Converted to date or time:Date, time, timestamp2, time and date:Year, quarter, month, week, day, hour, minute, secondDayofyear (ARG): returns the daily value of Arg in the yearDayofweek (ARG): returns the daily value of Arg in the weekDays (ARG): the integer representation of the return date, the number of days from the 0001-01-01.Midnight_seconds (ARG): the number of seconds between midnight and arg.Monthname (ARG): returns the month name of arg.Dayname (ARG): the week that returns arg.3 string function:Length, lcase, ucase, ltrim, rtrimCoalesce (arg1, arg2)... ) returns the first non null parameter in the argument set.Concat (arg1, arg2): connect two strings, arg1 and arg2.Insert (arg1, POS, size, arg2): returns a arg1 that removes size characters from POS and inserts arg2 into that location.Left (Arg, length): returns the leftmost length string of arg.Locate (arg1, arg2, <, pos>): find the location of the first occurrence of arg1 in arg2, specify POS, and start looking for the location of the arg1 from the POS of arg2.Posstr (arg1, arg2): returns the position where arg2 first appeared in arg1.Repeat (arg1, num_times): returns the string arg1 repeated num_times times.Replace (arg1, arg2, ARG3): replace all arg2 in arg1 to arg3.Right (Arg, length): returns a string consisting of lengthbytes on the left of the arg.Space (ARG): returns a string containing Arg spaces.Substr (arg1, POS, <, length>): returns the length character at the start of the POS position in arg1, and returns the remaining characters if no length is specified.4. Mathematical function:Abs, count, Max, min, sumCeil (ARG): returns the smallest integer greater than or equal to arg.Floor (ARG): returns the smallest integer less than or equal to the parameter.Mod (arg1,Arg2) returns arg1 by the remainder of the arg2, with the same symbol as arg1.Rand (): returns a random number between 1 and 1.Power (arg1, arg2): returns the arg2 power of arg1.Round (arg1, arg2): four, five into the truncated processing, arg2 is the number of bits, if arg2 is negative, then the number of decimal points before four to five processing.Sigh (ARG): symbolic designator to return arg. -1,0,1 representation.Truncate (arg1, arg2): truncate arg1, arg2 is the number of digits, and if arg2 is negative, keep the arg2 bits before the arg1 decimal point.5, others:Nullif (arg1, arg2): returns if the 2 arguments are equal, otherwise the argument 1 is returned。
SQL语句大全
SQL语句参考,包含Access、MySQL以及SQL Server基础创建数据库CREATE DATABASE database-name删除数据库drop database dbname备份sql server1.创建备份数据的device2. USE master3.EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'4.开始备份5.BACKUP DATABASE pubs TO testBack创建新表create table tabname(col1 type1 [not null] [primary key],c ol2 type2 [not null],..)根据已有的表创建新表:A:create table tab_new like tab_old (使用旧表创建新表)B:create table tab_new as select col1,col2… from tab_old d efinition only删除新表drop table tabname增加一个列Alter table tabname add column col type注:列增加后将不能删除。
DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。
添加主键Alter table tabname add primary key(col)删除主键Alter table tabname drop primary key(col)创建索引create [unique] index idxname on tabname(col….)删除索引drop index idxname注:索引是不可更改的,想更改必须删除重新建。
创建视图create view viewname as select statement删除视图drop view viewname几个简单的基本的sql语句选择:select * from table1 where 范围插入:insert into table1(field1,field2) values(value1,value 2)删除:delete from table1 where 范围更新:update table1 set field1=value1 where 范围查找:select * from table1 where field1 like ’%value1%’ ---l ike的语法很精妙,查资料!排序:select * from table1 order by field1,field2 [desc]总数:select count as totalcount from table1求和:select sum(field1) as sumvalue from table1平均:select avg(field1) as avgvalue from table1最大:select max(field1) as maxvalue from table1最小:select min(field1) as minvalue from table1几个高级查询运算词UNION 运算符UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。
经典SQLSERVER语句大全
1.一、基础2.1、说明:创建数据库3.CREATE DATABASE database-name4.2、说明:删除数据库5.drop database dbname6.7.3、说明:备份sql server8.--- 创建备份数据的deviceE master10.EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'11.--- 开始备份12.BACKUP DATABASE test TO testBack13.14.4、说明:创建新表15.create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)16.根据已有的表创建新表:17.A:create table tab_new like tab_old (使用旧表创建新表)18.B:create table tab_new as select col1,col2… from tab_old definition only19.5、说明:删除新表20.drop table tabname21.6、说明:增加一个列22.Alter table tabname add column col type23.注:列增加后将不能删除。
DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。
24.7、说明:添加主键:Alter table tabname add primary key(col)25.说明:删除主键:Alter table tabname drop primary key(col)26.8、说明:创建索引:create [unique] index idxname on tabn ame(col….)27.删除索引:drop index idxname28.注:索引是不可更改的,想更改必须删除重新建。
厉害的sql语句
厉害的sql语句以下是一些常见的强大的SQL语句示例:
1. 查询表中的所有数据:
```
SELECT * FROM 表名;
```
2. 查询特定条件下的数据:
```
SELECT * FROM 表名 WHERE 条件;
```
3. 查询表中的数据并按照某一列进行排序:```
SELECT * FROM 表名 ORDER BY 列名;
```
4. 查询表中的数据并统计某一列的总和:```
SELECT SUM(列名) FROM 表名;
```
5. 查询表中的数据并进行分组统计:
```
SELECT 列名, COUNT(*) FROM 表名 GROUP BY 列名;
```
6. 查询表中的数据并进行连接查询:
```
SELECT 表1.列名, 表2.列名 FROM 表1 INNER JOIN 表2 ON 表1.列名 = 表2.列名;
```
7. 更新表中的数据:
```
UPDATE 表名 SET 列名 = 值 WHERE 条件;
```
8. 插入新数据到表中:
```
INSERT INTO 表名 (列1, 列2) VALUES (值1, 值2);
```
9. 删除表中的数据:
```
DELETE FROM 表名 WHERE 条件;
```
这些只是一些常见的SQL语句示例,SQL语言非常强大,可以进行
更复杂的查询和操作。
具体的语句根据具体的需求来编写。
SQL语句总结
SQL语句总结
1. 简介
SQL〔结构化查询语言〕是一种用于管理关系型数据库〔RDBMS〕的编程语言。
通过使用SQL语句,可以对数据库进行查询、更新、插入和删除等操作。
本文将总结一些常用的SQL语句,包括查询语句、更新语句、插入语句和删除语句。
2. 查询语句
2.1 SELECT
SELECT语句是SQL中最常用的查询语句,用于从数据库中检索数据。
它的根本语法如下:
SELECT 列名1, 列名2, ... FROM 表名 WHERE 条件;
其中,列名是要检索的表中的列的名称,可以是单个列名,也可以是多个列名,多个列名之间用逗号分隔。
表名是要从中检索数据的表的名称。
WHERE子句是可选的,用于指定检索数据的条件。
例如,要从名为。
SQL实用语句大全
SQL 语句大全语句 数据库操作 SELECT WHERE 检索数据行和列 筛选条件 SELECT 列名称 FROM 表名称 SELECT 列名称 FROM 表名称 WHERE 列 运算符 值 SELECT 列 1, SUM(列 2)AS 名称 FROM 表名称 GROUP BY 列 1 GROUP BY 对数据进行分组 Group By 与聚合函数 函数 sum(列名) max(列名) min(列名) AVG(列名) count(列名) 求和 最大值 最小值 平均值 统计记录数 作用 功能描述 语法having 子句限制的是组,而不是行。
HAVING 筛选条件组 where 子句中不能使用聚集函数,而 having 子句中可以。
(1)不能将 distinct 与行统计函数一起使用 (2)compute 列名称 by 子句中 列名称必须出现在选择列表中 (3)不能在含有 compute by 子句的语句中使用 select into 子句,因为包括 compute 子句的语句会产生不规则的行。
(4 ) 如果使用了 compute by 子句, 则必须使用 order by 子句, 而且 compute by COMPUTE 合计数据 子句中的列必须包含在 order by 子句中,并且对列的前后顺序和起始项都要一致 (说白了 compute by 子句中的列必须是 order by 子句中列表的全部,或者前边的 连续几个)。
(5)如果 compute 省略了 by ,则 order by 也可以省略 (6)如果 compute by 子句包含多列时,会将一个组(第一个列分的组)分成若 干个子组(利用后面的列),并对每层子组进行统计。
(7)使用多个 compute by 子句时,会分别按不同的组统计出结果。
详细信息还是 按照正常的第一个分组方式显示。
(8)compute by 子句中可以使用多个统计函数,他们互不影响 (9)compute by 子句中可以不包含 by ,而只用 compute 此时不对前面信息分 组,而只对全部信息进行统计。
SQL查询语句大全集锦(经典)
SQL查询语句大全集锦MYSQL查询语句大全集锦一、简单查询简单的Transact-SQL查询只包括选择列表、FROM子句和WHERE子句。
它们分别说明所查询列、查询的表或视图、以及搜索条件等。
例如,下面的语句查询testtable表中姓名为“张三”的nickname字段和email字段。
复制内容到剪贴板代码:SELECT `nickname`,`email`FROM `testtable`WHERE `name`='张三'(一) 选择列表选择列表(select_list)指出所查询列,它可以是一组列名列表、星号、表达式、变量(包括局部变量和全局变量)等构成。
1、选择所有列例如,下面语句显示testtable表中所有列的数据:复制内容到剪贴板代码:SELECT * FROM testtable2、选择部分列并指定它们的显示次序查询结果集合中数据的排列顺序与选择列表中所指定的列名排列顺序相同。
例如:复制内容到剪贴板代码:SELECT nickname,email FROM testtable3、更改列标题在选择列表中,可重新指定列标题。
定义格式为:列标题=列名列名列标题如果指定的列标题不是标准的标识符格式时,应使用引号定界符,例如,下列语句使用汉字显示列标题:复制内容到剪贴板代码:SELECT 昵称=nickname,电子邮件=email FROM testtable4、删除重复行SELECT语句中使用ALL或DISTINCT选项来显示表中符合条件的所有行或删除其中重复的数据行,默认为ALL。
使用DISTINCT选项时,对于所有重复的数据行在SELECT返回的结果集合中只保留一行。
5、限制返回的行数使用TOP n [PERCENT]选项限制返回的数据行数,TOP n说明返回n行,而TOP n PERCENT 时,说明n是表示一百分数,指定返回的行数等于总行数的百分之几。
例如:复制内容到剪贴板代码:SELECT TOP 2 * FROM `testtable`复制内容到剪贴板代码:SELECT TOP 20 PERCENT * FROM `testtable`(二) FROM子句FROM子句指定SELECT语句查询及与查询相关的表或视图。
sql的as的用法和一些经典的sql语句
sql的as的用法和一些经典的sql语句--------------------------------------------------------------------------------作者:未知发布时间:2008-08-26 08:50:06 来源:网络总结一些工作中用到或碰到的SQL语句,希望能与大家分享,同时也希望大家能提供更多的精妙SQL语句1、delete table1 from (select * from table2) as t2 where table1.id=t2.id2、truncate table table1 (不在事务日志中做记录,比delete table快,但不能激活触发器)3、update table1 set column=column+1 where id=(select id from table2)4、update table1 set column=column+1 from table1,table2 where table1.id=table2.id5、select top n [Percent] * from table1 '输出百分比记录6、select id,column1 * column2 as column from table1 '可算明白as的用法了7、select * from table1 where column1 like 'SQL#_G_O' escape '#' '单匹配8、select table1.id from table1 where not exists (select table2.id from table2 where table1.id=table2.id) '这个应该比not in快一些9、select table1.id from table1,table2 where table1.id<>table2.id '看复合查询机制10、select table1.id from table1,table2,(select id from table3) as t3 where table1.id=table2.id and table2.id=t3.id '有些类似[1]了......11、select * from table1 where column1 like '[A]%' or like '[^B]%'12、select @column1=column1 from table1;select @column1 as column1 '存储到自定义变量13、select * from table1 where contains(column1,'char1 or char2*') '全文索引14、select * from table1 where contains(column1,'前有 near 中有 near 后有')15、select * from table1 where contains(column1,'formsof(inflectional,go)') '派生16、select * from table1 where contains(description,'isabout(apple weight(.9),boy weight(.8),china weight(.7))') '权重17、select * from table1 where freetext(column1,'char') '仅支持文字不支持表达式搜索18、insert into table1 select column1,count(column1) from table2 group by column1 '统计-----------------------------------------------------------------------------------------1 说明:复制表(只复制结构,源表名:a 新表名:b)SQL: select * into b from a where 1<>12 说明:拷贝表(拷贝数据,源表名:a 目标表名:b)SQL: insert into b(a, b, c) select d,e,f from b;3 说明:显示文章、提交人和最后回复时间SQL: select a.title,ername,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b4 说明:外连接查询(表名1:a 表名2:b)SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c5 说明:日程安排提前五分钟提醒SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>56 说明:两张关联表,删除主表中已经在副表中没有的信息SQL:delete from info where not exists ( select * from infobz where info.infid=infobz.infid )7 说明:从数据库中去一年的各单位电话费统计(电话费定额和电话费清单两个表来源)SQL:SELECT erper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear, SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC FROM (SELECT erper, a.tel, a.standfee, b.telfeedate, b.factrationFROM TELFEESTAND a, TELFEE bWHERE a.tel = b.telfax) aGROUP BY erper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')8 说明:四表联查问题:SQL: select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....9 说明:得到表中最小的未使用的ID号SQL:SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleIDFROM HandleWHERE NOT HandleID IN (SELECT a.HandleID - 1 FROM Handle a) 10 说明:模糊查询,单字匹配(短横线代表待匹配内容)select * from table where field1 like 'A_B_C'11 说明:as的用法select id,column1 * column2 as column from table1。
SQL常用语句总结大全
一、基础1、说明:创建数据库CREATE DATABASE database-name2、说明:删除数据库drop database dbname3、说明:备份sql server--- 创建备份数据的 deviceUSE masterEXEC sp_addumpdevice 'disk', 'testBack','c:\mssql7backup\MyNwind_1.dat'--- 开始备份BACKUP DATABASE pubs TO testBack4、说明:创建新表create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)根据已有的表创建新表:A:create table tab_new like tab_old (使用旧表创建新表)B:create table tab_new as select col1,col2… from tab_old definition only5、说明:删除新表drop table tabname6、说明:增加一个列Alter table tabname add column col type注:列增加后将不能删除。
DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。
7、说明:添加主键:Alter table tabname add primary key(col)说明:删除主键: Alter table tabname drop primary key(col)8、说明:创建索引:create [unique] index idxname on tabname(col….) 删除索引:drop index idxname注:索引是不可更改的,想更改必须删除重新建。
9、说明:创建视图:create view viewname as select statement删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select * from table1 where 范围插入:insert into table1(field1,field2) values(value1,value2)删除:delete from table1 where 范围更新:update table1 set field1=value1 where 范围查找:select * from table1 where field1 like ’%value1%’ ---like的语法很精妙,查资料!排序:select * from table1 order by field1,field2 [desc]总数:select count as totalcount from table1求和:select sum(field1) as sumvalue from table1平均:select avg(field1) as avgvalue from table1最大:select max(field1) as maxvalue from table1最小:select min(field1) as minvalue from table111、说明:几个高级查询运算词A: UNION 运算符UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。
经典SQL语句
1.Create database database_name --创建数据库On primary --创建主数据文件:mdf(name=‘name1’,Filename=‘磁盘名:\文件夹名\name1.mdf’,Size=,Maxsize=,Filegrowth=),(name=‘name2’,--创建次要数据文件(可以创建多个次要数据文件):ndfFilename=‘磁盘名:\文件夹名\name2.ndf’,Size=,Maxsize=,Filegrowth=)Log on --创建日志文件(可以创建多个日志文件):ldf(name=‘name3’,Filename=‘磁盘名:\文件夹名\name3.ldf’,Size=,Maxsize=,Filegrowth=)注意:多个次要数据文件和日志文件之间用‘,’隔开。
主要文件,次要文件,日志文件可以放在不同的磁盘里2.创建表Create table table_name(列名1 类型,列名2 类型,列名3 类型)注意:1.创建外键时该列不能为空,一个表内只能有一个主键,可以有多唯一约束2.创建联合主键(只能创建表级约束)Foreign key (列名1,列名2)3.修改表示添加列、列约束、修改约束、删除约束、删除列、删除表Alter table table_name[add column_name date_type][add constraint_name for column_name][alter column column_name new_data_type][drop column column_name | drop constraint constraint_name]4.DMLl语句(insert,update,delete)Insert into (列名1,列名2,列名3.··)values (值1,值2,值3,···)Update 表名set 列名=exprestion where 条件语句Delete form title_name where 条件语句5.(1)查看表结构:exec sp_help 表名(2)查看表内容:select *(列名1,列名2,。
sql语录
sql语录1. "数据库是计算机科学的灵魂。
" - Larry Ellison2. "数据就是一切。
" - Richard Campbell3. "我就是一个SQL驱动的机器。
" - Anonymous4. "SQL语言是计算机界的乐谱。
" - Chris Date5. "如果你不懂数据库,你就不懂计算机。
" - Roy Thomas Fielding6. "无论你使用什么编程语言,了解SQL都是必不可少的。
" - John Ousterhout7. "SQL是一个强大而精确的工具,可以让你从海量数据中提取有价值的信息。
" - Anonymous8. "通过SQL,你可以与数据库交流,就像与一个聪明的机器对话一样。
" - Anonymous9. "SQL是数据的魔术师,可以在你眨眼的间隙内完成惊人的计算。
" - Anonymous10. "SQL不仅仅是一种语言,还是一种思维方式。
" - Joe Celko11. "SQL就是一种艺术,可以将你的数据变成有用的信息。
" - Anonymous12. "SQL是获得信息宝藏的秘密钥匙。
" - Anonymous13. "无论你是管理数据还是分析数据,SQL都是你的得力助手。
" - Anonymous14. "SQL的美妙之处在于它的简洁与高效。
" - Anonymous15. "通过SQL,你可以轻松地完成复杂的数据操作,提高工作效率。
" - Anonymous。
SQL数据库语句大全大全(完全整理版)
SQL语句大全--语句功能--数据操作SELECT --从数据库表中检索数据行和列INSERT --向数据库表添加新数据行DELETE --从数据库表中删除数据行UPDATE --更新数据库表中的数据-数据定义CREATE TABLE --创建一个数据库表DROP TABLE --从数据库中删除表ALTER TABLE --修改数据库表结构CREATE VIEW --创建一个视图DROP VIEW --从数据库中删除视图CREATE INDEX --为数据库表创建一个索引DROP INDEX --从数据库中删除索引CREATE PROCEDURE --创建一个存储过程DROP PROCEDURE --从数据库中删除存储过程CREATE TRIGGER --创建一个触发器DROP TRIGGER --从数据库中删除触发器CREATE SCHEMA --向数据库添加一个新模式DROP SCHEMA --从数据库中删除一个模式CREATE DOMAIN --创建一个数据值域ALTER DOMAIN --改变域定义DROP DOMAIN --从数据库中删除一个域--数据控制GRANT --授予用户访问权限DENY --拒绝用户访问REVOKE --解除用户访问权限--事务控制COMMIT --结束当前事务ROLLBACK --中止当前事务SET TRANSACTION --定义当前事务数据访问特征--程序化SQLDECLARE --为查询设定游标EXPLAN --为查询描述数据访问计划OPEN --检索查询结果打开一个游标FETCH --检索一行查询结果CLOSE --关闭游标PREPARE --为动态执行准备SQL 语句EXECUTE --动态地执行SQL 语句DESCRIBE --描述准备好的查询---局部变量declare @id char(10)--set @id = '10010001'select @id = '10010001'---全局变量---必须以@@开头--IF ELSEdeclare @x int @y int @z intselect @x = 1 @y = 2 @z=3if @x > @yprint 'x > y' --打印字符串'x > y'else if @y > @zprint 'y > z'else print 'z > y'--CASEuse panguupdate employeeset e_wage =casewhen job_level = ’1’ then e_wage*1.08 when job_level = ’2’ then e_wage*1.07 when job_level = ’3’ then e_wage*1.06 else e_wage*1.05end--WHILE CONTINUE BREAK declare @x int @y int @c intselect @x = 1 @y=1while @x < 3beginprint @x --打印变量x 的值while @y < 3beginselect @c = 100*@x + @yprint @c --打印变量c 的值select @y = @y + 1endselect @x = @x + 1select @y = 1end--WAITFOR--例等待1 小时2 分零3 秒后才执行SELECT 语句w aitfor delay ’01:02:03’select * from employee--例等到晚上11 点零8 分后才执行SELECT 语句waitfor time ’23:08:00’select * from employee***SELECT***select *(列名) from table_name(表名) where column_name operator value ex:(宿主)select * from stock_information where stockid = str(nid)stockname = 'str_name'stockname like '% find this %'stockname like '[a-zA-Z]%' --------- ([]指定值的范围)stockname like '[^F-M]%' --------- (^排除指定范围)--------- 只能在使用like关键字的where子句中使用通配符)or stockpath = 'stock_path'or stocknumber < 1000and stockindex = 24not stock*** = 'man'stocknumber between 20 and 100stocknumber in(10,20,30)order by stockid desc(asc) --------- 排序,desc-降序,asc-升序order by 1,2 --------- by列号stockname = (select stockname from stock_information where stockid = 4)--------- 子查询--------- 除非能确保内层select只返回一个行的值,--------- 否则应在外层where子句中用一个in限定符select distinct column_name form table_name --------- distinct指定检索独有的列值,不重复select stocknumber ,"stocknumber + 10" = stocknumber + 10 from table_nameselect stockname , "stocknumber" = count(*) from table_name group by stockname--------- group by 将表按行分组,指定列中有相同的值having count(*) = 2 --------- having选定指定的组select *from table1, table2where table1.id *= table2.id -------- 左外部连接,table1中有的而table2中没有得以null表示table1.id =* table2.id -------- 右外部连接select stockname from table1union [all] ----- union合并查询结果集,all-保留重复行select stockname from table2***insert***insert into table_name (Stock_name,Stock_number) value ("xxx","xxxx")value (select Stockname , Stocknumber from Stock_table2)---value为select语句***update***update table_name set Stockname = "xxx" [where Stockid = 3]Stockname = defaultStockname = nullStocknumber = Stockname + 4***delete***delete from table_name where Stockid = 3truncate table_name ----------- 删除表中所有行,仍保持表的完整性drop table table_name --------------- 完全删除表***alter table*** --- 修改数据库表结构alter table database.owner.table_name add column_name char(2) null .....sp_help table_name ---- 显示表已有特征create table table_name (name char(20), age smallint, lname varchar(30))insert into table_name select ......... ----- 实现删除列的方法(创建新表)alter table table_name drop constraint Stockname_default ---- 删除Stockname的default约束***function(/*常用函数*/)***----统计函数----AVG --求平均值COUNT --统计数目MAX --求最大值MIN --求最小值SUM --求和--AVGuse panguselect avg(e_wage) as dept_avgWagefrom employeegroup by dept_id--MAX--求工资最高的员工姓名use panguselect e_namefrom employeewhere e_wage =(select max(e_wage)from employee)--STDEV()--STDEV()函数返回表达式中所有数据的标准差--STDEVP()--STDEVP()函数返回总体标准差--VAR()--VAR()函数返回表达式中所有值的统计变异数--VARP()--VARP()函数返回总体变异数----算术函数----/***三角函数***/SIN(float_expression) --返回以弧度表示的角的正弦COS(float_expression) --返回以弧度表示的角的余弦TAN(float_expression) --返回以弧度表示的角的正切COT(float_expression) --返回以弧度表示的角的余切/***反三角函数***/ASIN(float_expression) --返回正弦是FLOAT 值的以弧度表示的角ACOS(float_expression) --返回余弦是FLOAT 值的以弧度表示的角ATAN(float_expression) --返回正切是FLOAT 值的以弧度表示的角ATAN2(float_expression1,float_expression2)--返回正切是float_expression1 /float_expres-sion2的以弧度表示的角DEGREES(numeric_expression)--把弧度转换为角度返回与表达式相同的数据类型可为--INTEGER/MONEY/REAL/FLOAT 类型RADIANS(numeric_expression) --把角度转换为弧度返回与表达式相同的数据类型可为--INTEGER/MONEY/REAL/FLOAT 类型EXP(float_expression) --返回表达式的指数值LOG(float_expression) --返回表达式的自然对数值LOG10(float_expression)--返回表达式的以10 为底的对数值SQRT(float_expression) --返回表达式的平方根/***取近似值函数***/CEILING(numeric_expression) --返回>=表达式的最小整数返回的数据类型与表达式相同可为--INTEGER/MONEY/REAL/FLOAT 类型FLOOR(numeric_expression) --返回<=表达式的最小整数返回的数据类型与表达式相同可为--INTEGER/MONEY/REAL/FLOAT 类型ROUND(numeric_expression) --返回以integer_expression 为精度的四舍五入值返回的数据--类型与表达式相同可为INTEGER/MONEY/REAL/FLOAT 类型ABS(numeric_expression) --返回表达式的绝对值返回的数据类型与表达式相同可为--INTEGER/MONEY/REAL/FLOAT 类型SIGN(numeric_expression) --测试参数的正负号返回0 零值1 正数或-1 负数返回的数据类型--与表达式相同可为INTEGER/MONEY/REAL/FLOAT 类型PI() --返回值为π 即3.1415926535897936RAND([integer_expression]) --用任选的[integer_expression]做种子值得出0-1 间的随机浮点数----字符串函数----ASCII() --函数返回字符表达式最左端字符的ASCII 码值CHAR() --函数用于将ASCII 码转换为字符--如果没有输入0 ~ 255 之间的ASCII 码值CHAR 函数会返回一个NULL 值LOWER() --函数把字符串全部转换为小写UPPER() --函数把字符串全部转换为大写STR() --函数把数值型数据转换为字符型数据LTRIM() --函数把字符串头部的空格去掉RTRIM() --函数把字符串尾部的空格去掉LEFT(),RIGHT(),SUBSTRING() --函数返回部分字符串CHARINDEX(),PATINDEX() --函数返回字符串中某个指定的子串出现的开始位置SOUNDEX() --函数返回一个四位字符码--SOUNDEX函数可用来查找声音相似的字符串但SOUNDEX函数对数字和汉字均只返回0 值DIFFERENCE() --函数返回由SOUNDEX 函数返回的两个字符表达式的值的差异--0 两个SOUNDEX 函数返回值的第一个字符不同--1 两个SOUNDEX 函数返回值的第一个字符相同--2 两个SOUNDEX 函数返回值的第一二个字符相同--3 两个SOUNDEX 函数返回值的第一二三个字符相同--4 两个SOUNDEX 函数返回值完全相同QUOTENAME() --函数返回被特定字符括起来的字符串/*select quotename('abc', '{') quotename('abc')运行结果如下----------------------------------{{abc} [abc]*/REPLICATE() --函数返回一个重复character_expression 指定次数的字符串/*select replicate('abc', 3) replicate( 'abc', -2)运行结果如下----------- -----------abcabcabc NULL*/REVERSE() --函数将指定的字符串的字符排列顺序颠倒REPLACE() --函数返回被替换了指定子串的字符串/*select replace('abc123g', '123', 'def')运行结果如下----------- -----------abcdefg*/SPACE() --函数返回一个有指定长度的空白字符串STUFF() --函数用另一子串替换字符串指定位置长度的子串----数据类型转换函数----CAST() 函数语法如下CAST() (<expression> AS <data_ type>[ length ])CONVERT() 函数语法如下CONVERT() (<data_ type>[ length ], <expression> [, style])select cast(100+99 as char) convert(varchar(12), getdate())运行结果如下------------------------------ ------------199 Jan 15 2000----日期函数----DAY() --函数返回date_expression 中的日期值MONTH() --函数返回date_expression 中的月份值YEAR() --函数返回date_expression 中的年份值DATEADD(<datepart> ,<number> ,<date>)--函数返回指定日期date 加上指定的额外日期间隔number 产生的新日期DATEDIFF(<datepart> ,<number> ,<date>)--函数返回两个指定日期在datepart 方面的不同之处DATENAME(<datepart> , <date>) --函数以字符串的形式返回日期的指定部分DATEPART(<datepart> , <date>) --函数以整数值的形式返回日期的指定部分GETDATE() --函数以DATETIME 的缺省格式返回系统当前的日期和时间----系统函数----APP_NAME() --函数返回当前执行的应用程序的名称COALESCE() --函数返回众多表达式中第一个非NULL 表达式的值COL_LENGTH(<'table_name'>, <'column_name'>) --函数返回表中指定字段的长度值COL_NAME(<table_id>, <column_id>) --函数返回表中指定字段的名称即列名DATALENGTH() --函数返回数据表达式的数据的实际长度DB_ID(['database_name']) --函数返回数据库的编号DB_NAME(database_id) --函数返回数据库的名称HOST_ID() --函数返回服务器端计算机的名称HOST_NAME() --函数返回服务器端计算机的名称IDENTITY(<data_type>[, seed increment]) [AS column_name])--IDENTITY() 函数只在SELECT INTO 语句中使用用于插入一个identity column列到新表中/*select identity(int, 1, 1) as column_nameinto newtablefrom oldtable*/ISDATE() --函数判断所给定的表达式是否为合理日期ISNULL(<check_expression>, <replacement_value>) --函数将表达式中的NULL 值用指定值替换ISNUMERIC() --函数判断所给定的表达式是否为合理的数值NEWID() --函数返回一个UNIQUEIDENTIFIER 类型的数值NULLIF(<expression1>, <expression2>)--NULLIF 函数在expression1 与expression2 相等时返回NULL 值若不相等时则返回expression1 的值sql中的保留字action add aggregate allalter after and asasc avg avg_row_length auto_incrementbetween bigint bit binaryblob bool both bycascade case char characterchange check checksum columncolumns comment constraint createcross current_date current_time current_timestampdata database databases datedatetime day day_hour day_minuteday_second dayofmonth dayofweek dayofyeardec decimal default delayeddelay_key_write delete desc describedistinct distinctrow double dropend else escape escapedenclosed enum explain existsfields file first floatfloat4 float8 flush foreignfrom for full functionglobal grant grants grouphaving heap high_priority hourhour_minute hour_second hosts identifiedignore in index infileinner insert insert_id intinteger interval int1 int2int3 int4 int8 intoif is isam joinkey keys kill last_insert_idleading left length likelines limit load locallock logs long longbloblongtext low_priority max max_rowsmatch mediumblob mediumtext mediumintmiddleint min_rows minute minute_secondmodify month monthname myisamnatural numeric no notnull on optimize optionoptionally or order outeroutfile pack_keys partial passwordprecision primary procedure processprocesslist privileges read realreferences reload regexp renamereplace restrict returns revokerlike row rows secondselect set show shutdownsmallint soname sql_big_tables sql_big_selectssql_low_priority_updates sql_log_off sql_log_update sql_select_limit sql_small_result sql_big_result sql_warnings straight_joinstarting status string tabletables temporary terminated textthen time timestamp tinyblobtinytext tinyint trailing totype use using uniqueunlock unsigned update usagevalues varchar variables varyingvarbinary with write whenwhere year year_month zerofill查看全文常用SQL命令和ASP编程在进行数据库操作时,无非就是添加、删除、修改,这得设计到一些常用的SQL 语句,如下:SQL常用命令使用方法:(1) 数据记录筛选:sql="select * from 数据表where 字段名=字段值order by 字段名[desc]"sql="select * from 数据表where 字段名like %字段值% order by 字段名[desc]"sql="select top 10 * from 数据表where 字段名order by 字段名[desc]"sql="select * from 数据表where 字段名in (值1,值2,值3)"sql="select * from 数据表where 字段名between 值1 and 值2"(2) 更新数据记录:sql="update 数据表set 字段名=字段值where 条件表达式"sql="update 数据表set 字段1=值1,字段2=值2 …… 字段n=值n where 条件表达式"(3) 删除数据记录:sql="delete from 数据表where 条件表达式"sql="delete from 数据表" (将数据表所有记录删除)(4) 添加数据记录:sql="insert into 数据表(字段1,字段2,字段3 …) valuess (值1,值2,值3 …)"sql="insert into 目标数据表select * from 源数据表" (把源数据表的记录添加到目标数据表)(5) 数据记录统计函数:AVG(字段名) 得出一个表格栏平均值COUNT(*|字段名) 对数据行数的统计或对某一栏有值的数据行数统计MAX(字段名) 取得一个表格栏最大的值MIN(字段名) 取得一个表格栏最小的值SUM(字段名) 把数据栏的值相加引用以上函数的方法:sql="select sum(字段名) as 别名from 数据表where 条件表达式"set rs=conn.excute(sql)用rs("别名") 获取统的计值,其它函数运用同上。
精妙SQL语句介绍
目录1.在现有表中添加字段 (1)2.查询从第30条到第40条的记录数 (1)3.复制表结构(b表不存在,a表存在) (1)4.拷贝表数据(原表名:a 目标表名:b) (2)5.外连接查询 (2)6.快速插入2万条数据 (3)7.分页 (3)1.在现有表中添加字段/*SQL数据库*/alter table tablename add fieldname fieldtype2.查询从第30条到第40条的记录数/*SQL数据库*/select top10 *from temp where id not in(select top30 id from temp order by id asc)order by id asc/*ORACLE数据库*/select*from(select rownum m,a.*from temp a)where m>=30 and m<=40 order by id asc3.复制表结构(b表不存在,a表存在)/*SQL数据库*/select*into b from a/*ORACLE数据库*/create table b as select*from a where 1=2create table b as select*from a//复制表结构并且复制数据4.拷贝表数据(原表名:a 目标表名:b)/*SQL数据库、ORACLE数据库*/insert into b(c,d,e)select f,g,h from a5.外连接查询外连接就是查两张表左连接就是左边的表全有值,右边的值可以为空(+)右连接就是左边表值可以为空(+),右边表的值全有全连接是左连接和右连接的并集内连接是左连接和右连接的交集交叉连接,查看的表的笛卡尔积/*ORACLE数据库*/1、左连接select stname, e.departmentid, d.departmentnamefrom employees eleft outer join departments don (e.departmentid = d.departmentid);等价于select stname, e.departmentid, d.departmentnamefrom employees e, departments dwhere e.departmentid=d.departmentid(+);查询结果:所有员工及对应部门的记录,包括没有对应部门编号departmentid的员工记录。
数据库基本SQL语句大全
数据库基本_SQL语句大全学会数据库是很实用D~~记录一些常用的sql语句...有入门有提高有见都没见过的...好全...收藏下...其实一般用的就是查询,插入,删除等语句而已....但学学存储过程是好事...以后数据方面的东西就不用在程序里搞喽..而且程序与数据库只要一个来回通讯就可以搞定所有数据的操作....一、基础1、说明:创建数据库Create DATABASE database-name2、说明:删除数据库drop database dbname3、说明:备份sql server--- 创建备份数据的deviceUSE masterEXEC sp_addumpdevice ‘disk‘, ‘testBack‘, ‘c:\mssql7backup\‘--- 开始备份BACKUP DATABASE pubs TO testBack4、说明:创建新表create table tabnamecol1 type1 not null primary key,col2 type2 not null,..根据已有的表创建新表:A:create table tab_new like tab_old 使用旧表创建新表B:create table tab_new as select col1,col2… from tab_old definition only 5、说明:删除新表drop table tabname6、说明:增加一个列Alter table tabname add column col type注:列增加后将不能删除;DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度;7、说明:添加主键:Alter table tabname add primary keycol说明:删除主键:Alter table tabname drop primary keycol8、说明:创建索引:create unique index idxname on tabnamecol….删除索引:drop index idxname注:索引是不可更改的,想更改必须删除重新建;9、说明:创建视图:create view viewname as select statement删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select from table1 where 范围插入:insert into table1field1,field2 valuesvalue1,value2删除:delete from table1 where 范围更新:update table1 set field1=value1 where 范围查找:select from table1 where field1 like ’%value1%’ ---like的语法很精妙,查资料排序:select from table1 order by field1,field2 desc总数:select count as totalcount from table1求和:select sumfield1 as sumvalue from table1平均:select avgfield1 as avgvalue from table1最大:select maxfield1 as maxvalue from table1最小:select minfield1 as minvalue from table111、说明:几个高级查询运算词A:UNION 运算符UNION 运算符通过组合其他两个结果表例如TABLE1 和TABLE2并消去表中任何重复行而派生出一个结果表;当ALL 随UNION 一起使用时即UNION ALL,不消除重复行;两种情况下,派生表的每一行不是来自TABLE1 就是来自TABLE2;B:EXCEPT 运算符EXCEPT 运算符通过包括所有在TABLE1 中但不在TABLE2 中的行并消除所有重复行而派生出一个结果表;当ALL 随EXCEPT 一起使用时EXCEPT ALL,不消除重复行;C:INTERSECT 运算符INTERSECT 运算符通过只包括TABLE1 和TABLE2 中都有的行并消除所有重复行而派生出一个结果表;当ALL 随INTERSECT 一起使用时INTERSECT ALL,不消除重复行;注:使用运算词的几个查询结果行必须是一致的;12、说明:使用外连接A、left outer join:左外连接左连接:结果集几包括连接表的匹配行,也包括左连接表的所有行;SQL: select , , , , , from a LEFT OUT JOIN b ON =B:right outer join:右外连接右连接:结果集既包括连接表的匹配连接行,也包括右连接表的所有行;C:full outer join:全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录;二、提升1、说明:复制表只复制结构,源表名:a 新表名:b Access可用法一:select into b from a where 1<>1法二:select top 0 into b from a2、说明:拷贝表拷贝数据,源表名:a 目标表名:b Access可用insert into ba, b, c select d,e,f from b;3、说明:跨数据库之间表的拷贝具体数据使用绝对路径Access可用insert into ba, b, c select d,e,f from b in ‘具体数据库’ where 条件例子:..from b in ‘"&"."&"\" &"‘ where..4、说明:子查询表名1:a 表名2:bselect a,b,c from a where a IN select d from b 或者: select a,b,c from a where a IN 1,2,35、说明:显示文章、提交人和最后回复时间select ,, from table a,select maxadddate adddate from table where = b6、说明:外连接查询表名1:a 表名2:bselect , , , , , from a LEFT OUT JOIN b ON =7、说明:在线视图查询表名1:aselect from Select a,b,c FROM a T where > 1;8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括select from table1 where time between time1 and time2select a,b,c, from table1 where a not between 数值1 and 数值29、说明:in 的使用方法select from table1 where a not in ‘值1’,’值2’,’值4’,’值6’10、说明:两张关联表,删除主表中已经在副表中没有的信息delete from table1 where not exists select from table2 where =11、说明:四表联查问题:select from a left inner join b on = right inner join c on = inner join d on = where .....12、说明:日程安排提前五分钟提醒SQL: select from 日程安排where datediff‘minute‘,f开始时间,getdate>513、说明:一条sql 语句搞定数据库分页select top 10 b. from select top 20 主键字段,排序字段from 表名order by 排序字段desc a,表名b where b.主键字段= a.主键字段order by a.排序字段14、说明:前10条记录select top 10 form table1 where 范围15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.select a,b,c from tablename ta where a=select maxa from tablename tb where =16、说明:包括所有在TableA 中但不在TableB和TableC 中的行并消除所有重复行而派生出一个结果表select a from tableA except select a from tableB except select a from tableC 17、说明:随机取出10条数据select top 10 from tablename order by newid18、说明:随机选择记录select newid19、说明:删除重复记录Delete from tablename where id not in select maxid from tablename group by col1,col2,...20、说明:列出数据库里所有的表名select name from sysobjects where type=‘U‘21、说明:列出表里的所有的sele ct name from syscolumns where id=object_id‘TableName‘22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case;select type,sumcase vender when ‘A‘ then pcs else 0 end,sumcase vender when ‘C‘ then pcs else 0 end,sumcase vender when ‘B‘ then pcs else 0 end FROM tablename group by type显示结果:type vender pcs电脑A 1电脑A 1光盘B 2光盘A 2手机B 3手机C 323、说明:初始化表table1TRUNCATE TABLE table124、说明:选择从10到15的记录select top 5 from select top 15 from table order by id asc table_别名order by id desc三、技巧1、1=1,1=2的使用,在SQL语句组合时用的较多“where 1=1” 是表示选择全部“where 1=2”全部不选,如:if strWhere =‘beginset strSQL = ‘select count as Total from ‘ + tblName + ‘ where ‘ + strWhere endelsebeginset strSQL = ‘select count as Total from ‘ + tblName + ‘‘end我们可以直接写成set strSQ L = ‘select count as Total from ‘ + tblName + ‘ where 1=1 安定‘+ strWhere2、收缩数据库--重建索引DBCC REINDEXDBCC INDEXDEFRAG--收缩数据和日志DBCC SHRINKDBDBCC SHRINKFILE3、压缩数据库dbcc shrinkdatabasedbname4、转移数据库给新用户以已存在用户权限exec sp_change_users_login ‘update_one‘,‘newname‘,‘oldname‘go5、检查备份集RESTORE VERIFYONLY from disk=‘E:\‘6、修复数据库Alter DATABASE dvbbs SET SINGLE_USERGODBCC CHECKDB‘dvbbs‘,repair_allow_data_loss WITH TABLOCKGOAlter DATABASE dvbbs SET MULTI_USERGO7、日志清除SET NOCOUNT ONDECLARE LogicalFileName sysname,MaxMinutes INT,NewSize INTUSE tablename -- 要操作的数据库名Select LogicalFileName = ‘tablename_log‘, -- 日志文件名MaxMinutes = 10, -- Limit on time allowed to wrap log.NewSize = 1 -- 你想设定的日志文件的大小M-- Setup / initializeDECLARE OriginalSize intSelect OriginalSize = sizeFROM sysfilesWhere name = LogicalFileNameSelect ‘Original Size of ‘ + db_name + ‘ LOG is ‘ + CONVERTVARCHAR30,OriginalSize + ‘ 8K pages or ‘ + CONVERTVARCHAR30,OriginalSize8/1024 + ‘MB‘FROM sysfilesWhere name = LogicalFileNameCreate TABLE DummyTransDummyColumn char 8000 not nullDECLARE Counter INT,StartTime DATETIME,TruncLog VARCHAR255Select StartTime = GETDATE,TruncLog = ‘BACKUP LOG ‘ + db_name + ‘ WITH TRUNCATE_ONLY‘DBCC SHRINKFILE LogicalFileName, NewSizeEXEC TruncLog-- Wrap the log if necessary.WHILE MaxMinutes > DATEDIFF mi, StartTime, GETDATE -- time has not expiredAND OriginalSize = Select size FROM sysfiles Where name = LogicalFileNameAND OriginalSize 8 /1024 > NewSizeBEGIN -- Outer loop.Select Counter = 0WHILE Counter < OriginalSize / 16 AND Counter < 50000 BEGIN -- updateInsert DummyTrans VALUES ‘Fill Log‘Delete DummyTransSelect Counter = Counter + 1ENDEXEC TruncLogENDSelect ‘Final Size of ‘ + db_name + ‘ LOG is ‘ + CONVERTVARCHAR30,size + ‘ 8K pages or ‘ + CONVERTVARCHAR30,size8/1024 + ‘MB‘FROM sysfilesWhere name = LogicalFileNameDrop TABLE DummyTransSET NOCOUNT OFF8、说明:更改某个表exec sp_changeobjectowner ‘tablename‘,‘dbo‘9、存储更改全部表Create PROCEDUREOldOwner as NVARCHAR128,NewOwner as NVARCHAR128ASDECLARE Name as NVARCHAR128DECLARE Owner as NVARCHAR128DECLARE OwnerName as NVARCHAR128 DECLARE curObject CURSOR FORselect ‘Name‘ = name,‘Owner‘ = user_nameuidfrom sysobjectswhere user_nameuid=OldOwnerorder by nameOPEN curObjectFETCH NEXT FROM curObject INTO Name, Owner WHILEFETCH_STATUS=0BEGINif Owner=OldOwnerbeginset OwnerName = OldOwner + ‘.‘ + rtrimNameexec sp_changeobjectowner OwnerName, NewOwnerend-- select name,NewOwner,OldOwnerFETCH NEXT FROM curObject INTO Name, Owner ENDclose curObjectdeallocate curObjectGO10、SQL SERVER中直接循环写入数据declare i intset i=1while i<30begininsert into test userid valuesiset i=i+1end。
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精妙SQL语句收集摘要:一、基础二、提升三、技巧正文:SQL语句先前写的时候,很容易把一些特殊的用法忘记,我特此整理了一下SQL语句操作。
一、基础1、说明:创建数据库Create DATABASE database-name2、说明:删除数据库drop database dbname3、说明:备份sql server--- 创建备份数据的deviceUSE masterEXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'--- 开始备份BACKUP DATABASE pubs TO testBack4、说明:创建新表create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) 根据已有的表创建新表:A:create table tab_new like tab_old (使用旧表创建新表)B:create table tab_new as select col1,col2... from tab_old definition only5、说明:删除新表drop table tabname6、说明:增加一个列Alter table tabname add column col type注:列增加后将不能删除。
DB2中列加上后数据类型也不能改变,唯一能改变的是增加var char类型的长度。
7、说明:添加主键:Alter table tabname add primary key(col)说明:删除主键:Alter table tabname drop primary key(col)8、说明:创建索引:create [unique] index idxname on tabname(col....)删除索引:drop index idxname注:索引是不可更改的,想更改必须删除重新建。
9、说明:创建视图:create view viewname as select statement删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select * from table1 where 范围插入:insert into table1(field1,field2) values(value1,value2)删除:delete from table1 where 范围更新:update table1 set field1=value1 where 范围查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! 排序:select * from table1 order by field1,field2 [desc]总数:select count as totalcount from table1求和:select sum(field1) as sumvalue from table1平均:select avg(field1) as avgvalue from table1最大:select max(field1) as maxvalue from table1最小:select min(field1) as minvalue from table111、说明:几个高级查询运算词A:UNION 运算符UNION 运算符通过组合其他两个结果表(例如TABLE1 和TABLE2)并消去表中任何重复行而派生出一个结果表。
当ALL 随UNION 一起使用时(即UNION ALL),不消除重复行。
两种情况下,派生表的每一行不是来自TABLE1 就是来自TABLE2。
B:EXCEPT 运算符EXCEPT 运算符通过包括所有在TABLE1 中但不在TABLE2 中的行并消除所有重复行而派生出一个结果表。
当ALL 随EXCEPT 一起使用时(EXCEPT ALL),不消除重复行。
C:INTERSECT 运算符INTERSECT 运算符通过只包括TABLE1 和TABLE2 中都有的行并消除所有重复行而派生出一个结果表。
当ALL 随INTERSECT 一起使用时(INTERSECT ALL),不消除重复行。
注:使用运算词的几个查询结果行必须是一致的。
12、说明:使用外连接A、left outer join:左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。
SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c B:right outer join:右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。
C:full outer join:全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。
二、提升1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用)法一:select * into b from a where 1<>1法二:select top 0 * into b from a2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用)insert into b(a, b, c) select d,e,f from b;3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用)insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where..4、说明:子查询(表名1:a 表名2:b)select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3)5、说明:显示文章、提交人和最后回复时间select a.title,ername,b.adddate from table a,(select max(adddate) adddate fro m table where table.title=a.title) b6、说明:外连接查询(表名1:a 表名2:b)select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c7、说明:在线视图查询(表名1:a )select * from (Select a,b,c FROM a) T where t.a > 1;8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括select * from table1 where time between time1 and time2select a,b,c, from table1 where a not between 数值1 and 数值29、说明:in 的使用方法select * from table1 where a [not] in ('值1','值2','值4','值6')10、说明:两张关联表,删除主表中已经在副表中没有的信息delete from table1 where not exists ( select * from table2 where table1.field1=ta ble2.field1 )11、说明:四表联查问题:select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner joi n d on a.a=d.d where .....12、说明:日程安排提前五分钟提醒SQL: select * from 日程安排where datediff('minute',f开始时间,getdate())>513、说明:一条sql 语句搞定数据库分页select top 10 b.* from (select top 20 主键字段,排序字段from 表名order by 排序字段desc) a,表名 b where b.主键字段= a.主键字段order by a.排序字段14、说明:前10条记录select top 10 * form table1 where 范围15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.)select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b)16、说明:包括所有在TableA 中但不在TableB和TableC 中的行并消除所有重复行而派生出一个结果表(select a from tableA ) except (select a from tableB) except (select a from tableC)17、说明:随机取出10条数据select top 10 * from tablename order by newid()18、说明:随机选择记录select newid()19、说明:删除重复记录Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)20、说明:列出数据库里所有的表名select name from sysobjects where type='U'21、说明:列出表里的所有的select name from syscolumns where id=object_id('TableName')22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。