Question

我有sql server表，带有架构

m_id ,
u_id ,
error ,
status_1 ,
status_2

目前，我正在使用查询一次更新所有行。

update [table_1] 
set status_1 = GETUTCDATE() 
where [m_id] % 2 != 0;

此查询使用m_id % 2 != 0更新所有行。

但不是这样，我想一次更新一行，也许使用C＃循环。请提出建议。

Answer 1

这是你可以做的，

                string cmdString = "select m_id from table_1");
                SqlCommand command = new SqlCommand(cmdString, conn);
                using (var reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        var m_Id = reader["m_id"];
                        if (macId != DBNull.Value)
                        {
                            cmdString = 
                            "update table_1 set last_status_update = GETUTCDATE() where [m_id] % 2 != 0 AND [m_id] ='" + m_Id + "';"

                            command = new SqlCommand(cmdString, conn);
                            command.ExecuteNonQuery();
                        }
                    }
                }

Answer 2

像

这样的东西

Update [table_1] 
set status_1 = GETUTCDATE() 
Where [m_id] = (select top 1 m_id from table_1 order. by status_1 desc)

每次执行时都应该执行一条记录。不知道为什么你会想要...而且显然只有少数才有用。否则在tsql循环中执行它

Answer 3

DECLARE @date DATETIME = GETUTCDATE()

WHILE (1=1) DO
BEGIN
  ;WITH s_cte AS (
  SELECT TOP 1 status_1 FROM table_1 WHERE [m_id] % 2 != 0 AND status_1 != @date
)
UPDATE s_cte SET status_1 = @date

  IF @@ROWCOUNT = 0 BREAK
END

如何使用c＃逐个更新SQL Server表行

3 个答案: