Thinkphp5.0框架的Db操作实例分析【连接、增删改查(2)

//删除一条记录
$res = Db::name('user')->where(['id'=>1])->delete();
//如果where条件是主键，可以这样写
$res = Db::name('user')->delete(1);

    //打印sql,where值为数组
    $sql = Db::name('user')->where(['id'=>1])->buildSql();
    dump($sql);
    //结果：SELECT * FROM `user` WHERE `id` = 1
    //打印sql,where值为两个参数
    $sql2 = Db::name('user')->where('id',1)->buildSql();
    dump($sql2);
    //结果：SELECT * FROM `user` WHERE `id` = 1
    //打印sql,where值为三个参数
    $sql3 = Db::name('user')->where('id','=',1)->buildSql();
    dump($sql3);
    //结果：SELECT * FROM `user` WHERE `id` = 1
    //打印sql,where多条件
    $sql4 = Db::name('user')->where([
      'id' => ['in',[1,2,3,4,5]],
      'age' => ['gt',10]
    ])->buildSql();
    dump($sql4);
    //结果：SELECT * FROM `user` WHERE `id` IN (1,2,3,4,5) AND `age` > 10
    //使用EXP表达式
    $sql5 = Db::name('user')->where('id','EXP','not in (2,5)')->buildSql();
    dump($sql5);
    //结果：SELECT * FROM `bw_user` WHERE ( `id` not in (2,5) )
    //可以使用连续的where条件
    $sql6 = Db::name('user')
      ->where('id','EXP','not in (2,5)')
      ->where('age','>',10)
      ->buildSql();
    dump($sql6);
    //结果：SELECT * FROM `bw_user` WHERE ( `id` not in (2,5) ) AND `age` > 10
    //如果多个where条件是or关系，使用whereOr
    $sql7 = Db::name('user')
      ->where('id','EXP','not in (2,5)')
      ->whereOr('age','>',10)
      ->buildSql();
    dump($sql7);
    //结果：SELECT * FROM `bw_user` WHERE ( `id` not in (2,5) ) OR `age` > 10

    //链式操作，常用方法
    $data = Db::name('user')
      ->where(['id','>',10])
      ->field('id,name,age')
      ->order('addtime desc')
      ->limit('10,5')
//      ->page('3,5') //limit((page-1)*5,5)
//      ->group('course')
      ->select();
    dump($data);