SQL语句，使用case when 实现批量更新数据

实例一：更新user表中id为1,2,3的记录中的status字段当id=1时，status设为"正常"；当id=2时，status设为"禁用"；当id=3时，status设为"过期"；

      update user set
            status = case id 
               when 1 then \'正常\'
               when 2 then \'禁用\'
               when 3 then \'过期\'
            end
      where id in (1,2,3);

实例二：更新user表中id为1,2,3的记录中的status、rank字段

      update user set
            status = case id 
               when 1 then \'正常\'
               when 2 then \'禁用\'
               when 3 then \'过期\'
            end,
            rank = case id
               when 1 then 1
               when 2 then 2
               when 3 then 3
            end
      where id in (1,2,3);

实例三：更新$data数组中的记录数不确定时，使用sql拼接的形式

      $ids = implode(",",array_column($data,\'id\')); //获取所有要更新的记录id

      $sql = "update user set status = case id ";
      foreach ($data as $item) {
          $id = $item[\'id\'];
          $status = $item[\'status\'];
          $sql .= " when " . $id . " then " . $status;
      }
      $sql .= " end where id in (" . $ids . ")";