QSQLITE使用整理，sql常用语句

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效果图
这里写图片描述

源码
注意：在.pro中添加QT += sql

#include <QCoreApplication>#include <QTextCodec>#include <QSqlDatabase>#include <QSqlQuery>#include <QTime>#include <QSqlError>#include <QtDebug>#include <QSqlDriver>#include <QSqlRecord>int main(int argc, char *argv[]){    QCoreApplication a(argc, argv);    QTextCodec::setCodecForLocale(QTextCodec::codecForLocale());    QSqlDatabase db =QSqlDatabase::addDatabase("QSQLITE");/*    db.setHostName("easybook-3313b0");          //设置数据库主机名    db.setDatabaseName("qtDB.db");              //设置数据库名    db.setUserName("aa");                //设置数据库用户名    db.setPassword("123456"); */                  //设置数据库密码    db.open();                                  //打开连接    //创建数据库表    QSqlQuery query;    bool success=query.exec("create table automobil(id int primary key,attribute varchar,type varchar,kind varchar,nation int,carnumber int,elevaltor int,distance int,oil int,temperature int)");    if(success)        qDebug()<<QObject::tr("数据库表创建成功！\n");    else        qDebug()<<QObject::tr("数据库表创建失败！\n");    //查询    query.exec("select * from automobil");    QSqlRecord rec = query.record();    qDebug() << QObject::tr("automobil表字段数：" )<< rec.count();    //插入记录    QTime t;    t.start();    query.prepare("insert into automobil values(?,?,?,?,?,?,?,?,?,?)");    long records=100;    for(int i=0;i<records;i++)    {        query.bindValue(0,i);        query.bindValue(1,"四轮");        query.bindValue(2,"轿车");        query.bindValue(3,"富康");        query.bindValue(4,rand()%100);        query.bindValue(5,rand()%10000);        query.bindValue(6,rand()%300);        query.bindValue(7,rand()%200000);        query.bindValue(8,rand()%52);        query.bindValue(9,rand()%100);        success=query.exec();        if(!success)        {            QSqlError lastError=query.lastError();            qDebug()<<lastError.driverText()<<QString(QObject::tr("插入失败"));        }    }    qDebug()<<QObject::tr("插入 %1 条记录，耗时：%2 ms").arg(records).arg(t.elapsed());    //排序    t.restart();    success=query.exec("select * from automobil order by id desc");    if(success)        qDebug()<<QObject::tr("排序 %1 条记录，耗时：%2 ms").arg(records).arg(t.elapsed());    else        qDebug()<<QObject::tr("排序失败！");    //更新记录    t.restart();    for(int i=0;i<records;i++)    {       query.clear();       query.prepare(QString("update automobil set attribute=?,type=?,"                             "kind=?,nation=?,"                             "carnumber=?,elevaltor=?,"                             "distance=?,oil=?,"                             "temperature=? where id=%1").arg(i));       query.bindValue(0,"四轮");       query.bindValue(1,"轿车");       query.bindValue(2,"富康");       query.bindValue(3,rand()%100);       query.bindValue(4,rand()%10000);       query.bindValue(5,rand()%300);       query.bindValue(6,rand()%200000);       query.bindValue(7,rand()%52);       query.bindValue(8,rand()%100);       success=query.exec();       if(!success)       {           QSqlError lastError=query.lastError();           qDebug()<<lastError.driverText()<<QString(QObject::tr("更新失败"));       }    }    qDebug()<<QObject::tr("更新 %1 条记录，耗时：%2 ms").arg(records).arg(t.elapsed());    //删除    t.restart();    query.exec("delete from automobil where id=15");    qDebug()<<QObject::tr("删除一条记录，耗时：%1 ms").arg(t.elapsed());    return 0;    //return a.exec();}

sql常用语句

#include "mainwindow.h"#include <QApplication>#include <QCoreApplication>#include <QTextCodec>#include <QtSql/QSqlDatabase>#include <QtSql/QSqlQuery>#include <QtSql/QSqlError>#include <QtSql/QSqlDriver>#include <QtSql/QSqlRecord>#include <QTime>#include <QDebug>int main(int argc, char *argv[]){    QApplication a(argc, argv);    //设置编码格式--    //QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));    QTextCodec::setCodecForLocale(QTextCodec::codecForLocale());    //添加Sqllite数据库驱动    QSqlDatabase db =QSqlDatabase::addDatabase("QSQLITE");    //设置要打开或创建的数据库名称    db.setDatabaseName("D:/MyDBTest/MyDB.db");    //如果没有打开，返回-1    if(!db.open()){        qDebug() << db.lastError();//打印未打开的错误信息        return -1;    }    QSqlQuery query;    //创建表格--crete table 表名(id varchar,name varchar,age int)    query.exec("create table mytable(id varchar primary key,name varchar)");    //从已有表格中取出几列创建新的表格--    //create table tableNew as select name,address from tableOld    //更改表格名称    //ALTER TABLE mytable RENAME TO mytablenew    //删除表格    //drop table 表格名称    //为表格插入新的一列    //ALTER TABLE table1 ADD COLUMN other varchar    //插入数据--insert into 表名 values('id1','name1',25)    //insert into table1(name,address) values('name2','address2')    query.exec(QString("insert into mytable values('id1','name1')"));    //更新数据--update table1 set name='new_name',age=20 where id='id1'    //更新表格中一整列的内容--update table age=10;将table1中的age列全部改为10    //删除一条记录    //delete from table1 where id='id1'    //delete from table2--删除表中所有的数据    //查询--select 字段名（用，隔开）from 表名 where 查询条件    //group by 分组的字段 having 筛选条件 order by 排序字段    //select * from table2 where id<>'id1'--<>表示不等于，为空的is null    //select * from table1 where name like "%热点%"--查找name中包含热点的数据(包含在首末)    // %表示0或者多个，_表格一个,   desc从大到小，asc从小到大    //select * from table1 where age between 10 and 20 order by desc    return a.exec();}

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