qt数据库用户接口

1.QSqlQueryModel *model = new QSqlQueryModel();

2.model->setQuery("SELECT table_er_id, table_group.group_name FROM

table_group,"

3."table_user WHERE table_group.group_id=table_user.group_id");

4.

5.for(int i = 0; i < model->rowCount(); i++)

6.{

7.qDebug() << model->record(i).value("user_id").toString();

8.qDebug() << model->record(i).value("group_name").toString();

9.}

1.sqlite3可以有多种多表查询方法，比如 select (select * from table2) from table1

where xxx=xxx;

1.select table1.abc from table1,table2 where table1.xxx=table

2.xxx;

1.select table1.abc from table1 inner join table2 on table1.xxx=table

2.xxx;

1.QSqlTableModel tablemodel; //单表查询

2.tablemodel.setTable("table_user"); //绑定表

3.tablemodel.setFilter("group_id=1"); //设置查询条件

4.tablemodel.select(); //查询

5.for(int i = 0; i < tablemodel.rowCount(); i++)

6.{

7.qDebug() << tablemodel.record(i).value(1).toString();

8.}

1.int UserID_Index = tablemodel.record().indexOf("user_id");

2.qDebug() << tablemodel.record(i).value(UserID_Index).toString();

1.tablemodel.record(i).value("user_id").toString();

1.QSqlRelationalTableModel *model = new QSqlRelationalTableModel();

2.model->setTable("table_user");

3.model->setRelation(1, QSqlRelation("table_group", "group_id",

"group_id")); //表明table_group.group_id是table_group的主键

4.model->setHeaderData(0, Qt::Horizontal, tr("工号"));

5.model->setHeaderData(1, Qt::Horizontal, tr("组别"));

6.

7.if(!model->select())

8.{

9.QMessageBox::critical(this, tr("错误提示"), model->lastError().text(),

QMessageBox::Cancel);

10.}