mysql - 将 mySQL 触发器转换为 SQL

Question

寻求帮助将此 mySQL 触发器转换为 TSQL。

CREATE TRIGGER IF not exists TF_WATCHLIST_PERSISTENCE_ADD_POSITION 
AFTER INSERT ON TF_WATCHLIST_PERSISTENCE
FOR EACH ROW
WHEN NEW.WATCHLIST_POSITION IS NULL
BEGIN 
    UPDATE TF_WATCHLIST_PERSISTENCE SET
    WATCHLIST_POSITION = (SELECT COUNT(*) - 1 FROM TF_WATCHLIST_PERSISTENCE WHERE WATCHLIST_USER = NEW.WATCHLIST_USER)
    WHERE rowid = NEW.rowid;
END;

Answer 1

感谢您的帮助

我最终得到了这个。

CREATE TRIGGER TF_WATCHLIST_PERSISTENCE_ADD_POSITION 
ON TF_WATCHLIST_PERSISTENCE
AFTER INSERT, UPDATE
AS
DECLARE @MyCursor CURSOR;
DECLARE @MyField_USER varchar(250);
DECLARE @MyField_ID varchar(250);
DECLARE @MyField_NewPos int

BEGIN 
SET @MyCursor = CURSOR FOR 
SELECT      WATCHLIST_USER
        ,   WATCHLIST_ID
FROM    inserted
WHERE inserted.WATCHLIST_POSITION is null

OPEN @MyCursor 
FETCH NEXT FROM @MyCursor
INTO @MyField_USER,  @MyField_ID

WHILE @@FETCH_STATUS = 0

BEGIN 
    set @MyField_NewPos = (SELECT MAX(WATCHLIST_POSITION) + 1 FROM TF_WATCHLIST_PERSISTENCE WHERE WATCHLIST_USER = @MyField_USER)
    print @MyField_NewPos

    update TF_WATCHLIST_PERSISTENCE 
        SET WATCHLIST_POSITION = ISNULL(@MyField_NewPos,0)
        WHERE       WATCHLIST_USER = @MyField_USER 
            AND     WATCHLIST_ID = @MyField_ID
            AND     WATCHLIST_POSITION IS NULL 

        Print @MyField_USER 
        Print @MyField_ID
        FETCH NEXT FROM @MyCursor
        INTO @MyField_USER,  @MyField_ID
END;


END;
CLOSE @MyCursor