SQL选择:如果存在则更新,否则插入 - 使用日期部分比较?

时间:2008-12-04 12:06:06

标签: sql sql-server sql-update

我需要使用以下字段更新数据库中的记录

[ID] int (AutoIncr. PK)
[ScorerID] int
[Score] int
[DateCreated] smalldatetime

如果今天的日期存在记录(只应检查日期部分,而不是时间)和给定的记分员,我想更新这个人和今天的分数值。如果得分手今天没有记录,我想创建一个新记录。

我正在试图弄清楚如何把它变成单个(这可能吗?)sql语句。顺便说一句,我正在使用MSSQl数据库和ExecuteNonQuery()方法来发出查询。

4 个答案:

答案 0 :(得分:16)

IF EXISTS (SELECT NULL FROM MyTable WHERE ScorerID = @Blah AND CONVERT(VARCHAR, DateCreated, 101) = CONVERT(VARCHAR, GETDATE(), 101))
    UPDATE MyTable SET blah blah blah
ELSE
    INSERT INTO MyTable blah blah blah

答案 1 :(得分:3)

其他人已经涵盖了2005(和之前)兼容的T-SQL / apprroaches。我只想补充一点,如果你有幸使用SQL Server 2008,你可以利用新的Merge(有时称为Upsert)语句。

我很难找到可以进一步解释的博客文章或文章,但我确实发现了(1) helpful entry。官方MSDN条目为(2) here.

(1)[http://www.sqlservercurry.com/2008/05/sql-server-2008-merge-statement.html]
(2)[http://msdn.microsoft.com/en-us/library/bb510625.aspx]

答案 2 :(得分:1)

CREATE PROCEDURE InsertOrUpdateScorer(@ScorerID INT, @Score INT)
AS
BEGIN
  IF EXISTS (
    SELECT 1 
    FROM Scorer 
    WHERE ScorerID = @ScorerID AND DATEDIFF(dd, GETDATE(), DateCreated) = 0
  )
  BEGIN
    UPDATE
      Scorer
    SET 
      Score = @Score
    WHERE
      ScorerID = @ScorerID

    RETURN @ScorerID
  END
  ELSE
  BEGIN
    INSERT 
      Scorer 
      (ScorerID, Score, DateCreated)
    VALUES
      (@ScorerID, @Score, GETDATE())

    RETURN SCOPE_IDENTITY()
  END
END

使用该程序的返回值来获取新的ScorerId。

SqlCommand UpdateScorer = New SqlCommand("InsertOrUpdateScorer", DbConn);
UpdateScorer.CommandType = CommandType.StoredProcedure;

SqlParameter RetValue = UpdateScorer.Parameters.Add("RetValue", SqlDbType.Int);
RetValue.Direction = ParameterDirection.ReturnValue;

SqlParameter Score = UpdateScorer.Parameters.Add("@Score", SqlDbType.Int);
Score.Direction = ParameterDirection.Input;

SqlParameter ScorerId = UpdateScorer.Parameters.Add("@ScorerID", SqlDbType.Int);
ScorerId.Direction = ParameterDirection.Input;

Score.Value = 15;    // whatever
ScorerId.Value = 15; // whatever

UpdateScorer.ExecuteNonQuery();
Console.WriteLine(RetValue.Value);

答案 3 :(得分:1)

对于需要一次更新或插入所有值的情况,不仅仅是我使用此代码段的一条记录

首先运行更新脚本<​​/ p>

UPDATE Table1 
SET OPIS = T1.OPIS
FROM
    Table1 AS T
INNER JOIN
    Table2 AS T1
    ON
        T.col = T1.col;

然后执行插入脚本

INSERT INTO Table1 
SELECT * FROM 
    (
        SELECT T1.* Table2 AS T1
        LEFT JOIN Table1 AS T2 ON (T2.col = T1.col)
        WHERE T2.col IS NULL
    ) AS T;

希望有人发现这很有用。

MySql中的相当于(在某些情况下)是这样的:

INSERT INTO table (a,b,c) VALUES (1,2,3)
  ON DUPLICATE KEY UPDATE c=c+1;

有人可以发现这与Solutions for INSERT OR UPDATE on SQL Server

上的文章有关

使用MERGE (Transact-SQL)更新版本:

DECLARE @USER_ID AS INT=76;
DECLARE @TYPE AS NVARCHAR(MAX)='set.global';
DECLARE @FKEY AS NVARCHAR(MAX)='21';
DECLARE @DATA AS NVARCHAR(MAX)='test';

        begin tran
            MERGE UserData
            USING (SELECT @USER_ID, @TYPE, @FKEY, @DATA) AS Source([UserId], [Type], [FKey], [Data])
            ON (UserData.[UserId] = Source.[UserId] AND UserData.[Type] = Source.[Type] AND (UserData.[FKey] = Source.[FKey] OR (Source.[FKey] IS NULL AND UserData.[FKey] IS NULL)))
            WHEN MATCHED
            THEN
                UPDATE SET [Data] = Source.[Data]
            WHEN NOT MATCHED BY TARGET THEN
                INSERT 
                           ([UserId]
                           ,[Type]
                           ,[FKey]
                           ,[Data])
                     VALUES
                           ( Source.[UserId]
                           ,Source.[Type]
                           ,Source.[FKey]
                           ,Source.[Data]);

        commit tran