如何在SQL中编写以下代码?该查询将从结果更新表中的每个列。
DECLARE @table_list NVARCHAR -- What data type do I use to hold a list?
DECLARE @column_list NVARCHAR
SET @table_list = (SELECT DISTINCT [ID_TABLE_NAME] FROM dbo.VMO) -- there are more than one results
SET @column_list = (SELECT DISTINCT [USR_COL_NAME] FROM dbo.VMO) -- there are more than one results
foreach(@table IN @table_list)
{
foreach(@column IN @column_list)
{
UPDATE @table
SET @column = '101211'
WHERE @column = '10120'
}
}
您可以使用CURSOR像foreach循环一样:
DECLARE @table NVARCHAR(255)
DECLARE @column NVARCHAR(255)
DECLARE OUTER_CURSOR CURSOR
FOR SELECT DISTINCT [ID_TABLE_NAME] FROM dbo.VMO
OPEN OUTER_CURSOR
FETCH NEXT FROM OUTER_CURSOR INTO @table
WHILE (@@FETCH_STATUS <> -1)
BEGIN
DECLARE INNER_CURSOR CURSOR
FOR SELECT DISTINCT [USR_COL_NAME] FROM dbo.VMO
OPEN INNER_CURSOR
FETCH NEXT FROM INNER_CURSOR INTO @column
WHILE (@@FETCH_STATUS <> -1)
BEGIN
DECLARE @strQuery NVARCHAR(MAX)
SET @strQuery = 'UPDATE [' + @table + '] SET [' + @column + '] = ''101211'' WHERE [' + @column + '] = ''10120'';'
EXEC(@strQUERY)
FETCH NEXT FROM INNER_CURSOR INTO @column
END
CLOSE INNER_CURSOR
DEALLOCATE INNER_CURSOR
FETCH NEXT FROM OUTER_CURSOR INTO @table
END
CLOSE OUTER_CURSOR
DEALLOCATE OUTER_CURSOR
T-SQL没有FOR loop
,也许它有一个WHILE (Transact-SQL)
使用如下SQL:
DECLARE @table_list NVARCHAR -- What data type do I use to hold a list?
DECLARE @column_list NVARCHAR
SET @table_list = (SELECT DISTINCT [ID_TABLE_NAME] FROM dbo.VMO) -- there are more than one results
SET @column_list = (SELECT DISTINCT [USR_COL_NAME] FROM dbo.VMO) -- there are more than one results
WHILE @column_list > @table_list
BEGIN
UPDATE @table
SET @column = '101211'
WHERE @column = '10120'
END;