存储过程中的临时表不访问数据？

Question

这是我的代码

create proc TEMP
    AS
    BEGIN
    DECLARE @SQL nvarchar(4000)
    IF OBJECT_ID(N'tempdb..#TEMP1') IS NOT NULL
        DROP TABLE #TEMP1;
    SET @SQL ='SELECT CUSTOMERS,AREA,HOUSEHOLDS'+CHAR(10)
    SET @SQL = @SQL +'INTO #TEMP1'+CHAR(10)
    SET @SQL = @SQL +'FROM NEW'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)
    IF OBJECT_ID(N'tempdb..#TEMP2') IS NOT NULL
        DROP TABLE #TEMP2;
    SET @SQL ='SELECT CUSTOMERS,AREA,VEHICELS'+CHAR(10)
    SET @SQL = @SQL +'INTO #TEMP2'+CHAR(10)
    SET @SQL = @SQL +'FROM OLD'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)
    IF OBJECT_ID(N'tempdb..#TEMP3') IS NOT NULL
        DROP TABLE #TEMP3;
    SET @SQL ='SELECT 0.VEHICELS,C.HOUSEHOLDS'+CHAR(10)
    SET @SQL = @SQL +'INTO #TEMP3'+CHAR(10)
    SET @SQL = @SQL +'FROM #TEMP1 C'+CHAR(10)
    SET @SQL = @SQL +'INNER JOIN #TEMP2 O '+CHAR(10)
    SET @SQL = @SQL +'on C.CUSTOMERS=O.CUSTOMERS'+CHAR(10)
    SET @SQL = @SQL +'AND C.AREA=O.AREA'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)
    END

我的错误：

Msg 208, Level 16, State 0, Line 1
Invalid object name '#TEMP1'.

第一个 TEMP1 和 TEMP2 运行良好，但是当涉及到 TEMP3 时，它不会访问存在数据的 TEMP1

你们能检查一下这个令人困惑的问题吗？？？

DECLARE @sql varchar(max)
SET @sql = 'CREATE TABLE ##T1 (Col1 varchar(20))'
EXEC(@sql)
INSERT INTO ##T1 (Col1) VALUES ('This will work.')
SELECT * FROM ##T1

如果我们使用全球临时表，我们将来会遇到任何问题吗？？？

Answer 1

一旦 exec 执行完毕，#temp 表就会被删除 也许如果你尝试使用更广泛的范围，它可能会成功，我不知道。

试试这样的。

create proc TEMP
AS
BEGIN
    DECLARE @now datetime;
    DECLARE @TempTableTableSuffix sysname
    SET @now = GETDATE()

    select @TempTableTableSuffix = CONVERT(VARCHAR, CONVERT(int,RAND(DATEPART(MILLISECOND,@now)+1000*(DATEPART(SECOND,@now)+60*(DATEPART(MINUTE,@now)+60*DATEPART(HOUR,@now)))) * 100000000))

    DECLARE @SQL nvarchar(4000)
    SET @SQL ='SELECT CUSTOMERS,AREA,HOUSEHOLDS'+CHAR(10)
    SET @SQL = @SQL +'INTO ##TEMP1' + @TempTableTableSuffix + CHAR(10)
    SET @SQL = @SQL +'FROM NEW'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)
    SET @SQL ='SELECT CUSTOMERS,AREA,VEHICELS'+CHAR(10)
    SET @SQL = @SQL +'INTO ##TEMP2' + @TempTableTableSuffix + CHAR(10)
    SET @SQL = @SQL +'FROM OLD'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)
    SET @SQL ='SELECT 0.VEHICELS,C.HOUSEHOLDS'+CHAR(10)
    SET @SQL = @SQL +'INTO ##TEMP3'+CHAR(10)
    SET @SQL = @SQL +'FROM ##TEMP1' + + @TempTableTableSuffix + '  C'+CHAR(10)
    SET @SQL = @SQL +'INNER JOIN #TEMP2'+ @TempTableTableSuffix  + ' O '+CHAR(10)
    SET @SQL = @SQL +'on C.CUSTOMERS=O.CUSTOMERS'+CHAR(10)
    SET @SQL = @SQL +'AND C.AREA=O.AREA'+CHAR(10)
    PRINT(@SQL)
    EXEC (@SQL)

END

无论如何，我认为您不需要dynamic SQL。

Answer 2

使用单个 EXEC -

DECLARE @SQL nvarchar(MAX)
IF OBJECT_ID(N'tempdb..#TEMP1') IS NOT NULL
    DROP TABLE #TEMP1;
IF OBJECT_ID(N'tempdb..#TEMP2') IS NOT NULL
    DROP TABLE #TEMP2;    
IF OBJECT_ID(N'tempdb..#TEMP3') IS NOT NULL
    DROP TABLE #TEMP3;        


SET @SQL = ' SELECT CUSTOMERS,AREA,HOUSEHOLDS'+CHAR(10)
SET @SQL = @SQL + ' INTO #TEMP1'+CHAR(10)
SET @SQL = @SQL + ' FROM NEW'+CHAR(10)

SET @SQL = @SQL + ' SELECT CUSTOMERS,AREA,VEHICELS'+CHAR(10)
SET @SQL = @SQL + ' INTO #TEMP2'+CHAR(10)
SET @SQL = @SQL + ' FROM OLD'+CHAR(10)
SET @SQL = @SQL + ' SELECT 0.VEHICELS,C.HOUSEHOLDS'+CHAR(10)
SET @SQL = @SQL + ' INTO #TEMP3'+CHAR(10)
SET @SQL = @SQL + ' FROM #TEMP1 C'+CHAR(10)
SET @SQL = @SQL + ' INNER JOIN #TEMP2 O '+CHAR(10)
SET @SQL = @SQL + ' on C.CUSTOMERS=O.CUSTOMERS'+CHAR(10)
SET @SQL = @SQL + ' AND C.AREA=O.AREA'+CHAR(10)
PRINT(@SQL)
EXEC (@SQL)