日期和表名称作为Dynamic SQL中的参数

Question

I'm Trying to create a stored procedure that will allow me to pick a start date and end date to get data from and to have a variable table name to write this data to.

I would like to pass in the two dates and the table name as parameters in the stored procedure. Here is that part I'm stuck on. I took out the stored procedure to try and get this working. this way I can see the lines the error is on.

DECLARE @MinDateWeek DATETIME
SELECT @MinDateWeek= DATEADD(WEEK, DATEDIFF(WEEK,0,GETDATE()), -7)
DECLARE @MaxDateWeek DATETIME
SELECT @MaxDateWeek= DATEADD(WEEK, DATEDIFF(WEEK,0,GETDATE()),0)
DECLARE @SQLCommand NVARCHAR(MAX)

    SET @SQLCommand = ' --ERROR ON THIS LINE
-- Getting how much space is used in the present
    DECLARE @Present Table (VMName NVARCHAR(50), UseSpace float(24))
    INSERT INTO @Present 
        SELECT  VMName
            ,SUM(CapacityGB-FreeSpaceGB)  
        FROM VMWareVMGuestDisk 

        GROUP BY VMName;
    -- Getting how much space was used at the reference date

    DECLARE @Past Table (VMName NVARCHAR(50), UseSpace float(24))
    INSERT INTO @Past
        SELECT  VMName
            ,SUM(CapacityGB-FreeSpaceGB)  
        FROM VMWareVMGuestDisk 
        WHERE Cast([Date] AS VARCHAR(20))= '''+CAST(@MinDateWeek AS varchar(20))+'''
        GROUP BY VMName;

    --Inserting the average growth(GB/DAY) between the 2 dates in a Temporary Table

    CREATE TABLE #TempWeek (VMName NVARCHAR(50) 
                    , CapacityGB float(24)
                    , GrowthLastMonthGB float(24)
                    , FreeSpace FLOAT(24) )

    INSERT INTO #TempWeek
    SELECT DISTINCT V.VMName
        ,SUM(V.CapacityGB)
        ,SUM(((W1.UseSpace-W2.UseSpace)/(DATEDIFF(DAY,'''+CONVERT(VARCHAR(50),@MaxDateWeek)+''','''+CONVERT(VARCHAR (50),@MaxDateWeek)+'''))))
        ,SUM(V.FreeSpaceGb)
    FROM VMWareVMGuestDisk AS V
        LEFT JOIN
        @Present AS W1
        ON
        V.VMName=W1.VMName
        LEFT JOIN
        @Past AS W2
        ON
        W1.VMName=W2.VMName
    WHERE (CONVERT(VARCHAR(15),Date))='''+CONVERT(VARCHAR(50),@MaxDateWeek)+'''
    GROUP BY V.VMName;

    -- Checking if there is already data in the table

            TRUNCATE TABLE SAN_Growth_Weekly;

    --insert data in permanent table
    INSERT INTO SAN_Growth_Weekly (VMName,Datacenter,Cluster,Company,DaysLeft,Growth,                                                             Capacity,FreeSpace,ReportDate)
        SELECT DISTINCT
            G.VMName
            ,V.Datacenter
            ,V.Cluster
            ,S.Company
            , DaysLeft = 
            CASE 
                WHEN G.GrowthLastMonthGB IS NULL 
                    THEN ''NO DATA''
                WHEN (G.GrowthLastMonthGB)<=0 
                    THEN ''UNKNOWN''
                WHEN (G.FreeSpace/G.GrowthLastMonthGB)>0 AND (G.FreeSpace/G.GrowthLastMonthGB) <=30 
                    THEN ''Less then 30 Days''
                WHEN (G.FreeSpace/G.GrowthLastMonthGB)>30 AND (G.FreeSpace/G.GrowthLastMonthGB)<=60                                 THEN ''Less then 60 Days''
                WHEN (G.FreeSpace/G.GrowthLastMonthGB)>60 AND (G.FreeSpace/G.GrowthLastMonthGB)<=90 
                    THEN ''Less then 90 Days''
                WHEN (G.FreeSpace/G.GrowthLastMonthGB)>90 AND (G.FreeSpace/G.GrowthLastMonthGB)<=180                                THEN ''Less then 180 Days''
                WHEN (G.FreeSpace/G.GrowthLastMonthGB)>180 AND (G.FreeSpace/G.GrowthLastMonthGB)<=365                               THEN ''Less then 1 Year''
                ELSE ''Over 1 Year''
            END
            ,G.GrowthLastMonthGB
            ,G.CapacityGB
            ,G.FreeSpace
            ,'''+@MaxDateWeek+'''
        FROM #tempWeek AS G
        RIGHT JOIN VMWareVMGuestDisk AS V
            ON V.VMName = G.VMName COLLATE SQL_Latin1_General_CP1_CI_AS
        LEFT JOIN Server_Reference AS S
            ON G.VMName COLLATE SQL_Latin1_General_CP1_CI_AS=S.[Asset Name]
        WHERE '''+CONVERT(VARCHAR(50),@MaxDateWeek)+'''= CONVERT(VARCHAR(50),V.Date);'

    EXEC sp_executesql @SQLCommand;

The error I get is

Conversion failed when converting date and/or time from character string.

Thanks for the help.

Answer 1

Are you forgetting to enclose your Group By in the dynamic sql?:

ALTER PROCEDURE SAN_DISK_GROWTH
    @MaxDateWeek DATETIME ,
    @MinDateWeek DATETIME
AS
    BEGIN
        DECLARE @SQLCommand NVARCHAR(MAX)
        SELECT  @SQLCommand = '
    DECLARE @Present Table (VMName NVARCHAR(50), UseSpace float(24))
    INSERT INTO @Present 
        SELECT  VMName
            ,SUM(CapacityGB - FreeSpaceGB)  
        FROM VMWareVMGuestDisk 
        WHERE CONVERT(VARCHAR(15),Date) = '''
                + CONVERT(VARCHAR(50), @MaxDateWeek) + ''' GROUP BY VMName;'

    END

Answer 2

Try specifying your date/time values as parameters to the dynamic SQL query. In other words, instead of converting the dates to a varchar, use parameters in the query:

WHERE @MaxDateWeek = V.Date;

And pass the parameters on the call to sp_executesql like so:

EXEC sp_executesql @SQLCommand,
    '@MindateWeek datetime, @MaxDateWeek datetime',
    @MinDateWeek = @MinDateWeek,
    @MaxDateWeek = @MaxDateWeek

Then you won't have to convert your dates to strings.

Note that this does not work for dynamic table names or column names. Those need to be concatenated together as part of the dynamic SQL itself.

For example, if you had a table name variable like this:

declare @TableName sysname
set @TableName = 'MyTable'

And you wanted the dynamic SQL to retrieve data from that table, then you would need to build your FROM statement like this:

set @SQLCommand = N'SELECT ...
    FROM ' + @TableName + N' WHERE...

This build the name into the SQL like so:

'SELECT ... FROM MyTable WHERE...'