TSQL正常运行，但不能通过sp_executesql

Question

I have some C# code that looks like this:

string strSql = "SELECT DISTINCT A." + strProcessingDateColumn
        + " FROM GA_Item A "
        + " WHERE A.TOWControlID = @TOWControlID"
        + " AND A.ItemTypeExt = 'PDF' "
        + " AND A." + strSourceColumn + " = 'Teller Report' "
        + " AND A." + strReportNumberColumn + " = @ReportNum "
        + " AND A." + strIBTColumn + " <> '9999' "
        + " AND ISNULL(A." + strMergedColumn + ", 'N') = 'N'"
        + " AND CAST(LTRIM(RTRIM(A." + strProcessingDateColumn + ")) AS DATETIME) < @ProcessingDate";
      using (SqlCommand command = new SqlCommand(strSql, conn))
      {
        command.Parameters.AddWithValue("@TOWControlID", iTOWControlID);
        command.Parameters.AddWithValue("@ReportNum", iReportNumber.ToString());
        command.Parameters.AddWithValue("@ProcessingDate", dtCurrentDate);
        try
        {
          using (SqlDataReader datereader = command.ExecuteReader())
          {
            while (datereader.Read())
            {
              //...
            }
          }
        }
      }

Which generates an sp_executesql statement (which I pulled from the SQL profiler) that looks like this:

exec sp_executesql N'SELECT DISTINCT A.UserField1 FROM GA_Item A
WHERE A.TOWControlID = @TOWControlID
    AND A.ItemTypeExt = ''PDF''
    AND A.UserField4 = ''Teller Report''
    AND A.UserField3 = @ReportNum
    AND A.UserField2 <> ''9999''
    AND ISNULL(A.UserField5, ''N'') = ''N''
    AND CAST(LTRIM(RTRIM(A.UserField1)) AS DATETIME) < @ProcessingDate'
,N'@TOWControlID int,@ReportNum nvarchar(1),@ProcessingDate datetime'
,@TOWControlID=9999
,@ReportNum=N'6'
,@ProcessingDate='2015-03-24 00:00:00'

Which results in 2 errors: The conversion of a nvarchar data type to a datetime data type resulted in an out-of-range value. and Conversion failed when converting date and/or time from character string.

That leads me to believe that something is causing an overflow in the table I'm selecting from. However, if I extract the query out of the sp_executesql statement so it looks like this:

declare @TOWControlID int = 9999,
        @ReportNum nvarchar = '6',
        @ProcessingDate datetime = '2015-03-24'
SELECT DISTINCT A.UserField1 FROM GA_Item A
WHERE A.TOWControlID = @TOWControlID
      AND A.ItemTypeExt = 'PDF'
      AND A.UserField4 = 'Teller Report'
      AND A.UserField3 = @ReportNum
      AND A.UserField2 <> '9999'
      AND ISNULL(A.UserField5, 'N') = 'N'
      AND CAST(LTRIM(RTRIM(A.UserField1 AS DATETIME))) < @ProcessingDate

The query works as expected.

The stranger thing is that this exact code used to work in SQL 2000, but we have migrated the system to use SQL 2008 and now we are getting this problem. I had an issue in SQL 2000 where the query straight up refused to run unless the datetime equality condition was the last one in the list, so once we moved it to the bottom of the list it worked fine for months.

I have checked and double checked and I cannot see anything wrong with the data I'm giving it, as well as the data in the table. I can convert every value in UserField1 (which is an nvarchar(256) ) to a datetime no problem in a separate query.

Am I missing something?

The schema of the table is quite large, so I won't post the whole thing here, but it basically boils down to UserField1-20 nvarchar(256), null , TOWControlID int null , and ItemTypeEXT nvarchar(50), null

I should also note that if I remove the AND CAST(LTRIM(RTRIM(A.UserField1)) AS DATETIME) < @ProcessingDate from the sp_executesql statement the query runs, but it doesn't get the right results.

Everything is pointing to a data error in the table, but if I run this:

declare @TOWControlID int = 9999,
        @ReportNum nvarchar = '6',
        @ProcessingDate datetime = '2015-03-24'
SELECT CAST(LTRIM(RTRIM(A.UserField1)) FROM GA_Item A
WHERE A.TOWControlID = @TOWControlID
      AND A.ItemTypeExt = 'PDF'
      AND A.UserField4 = 'Teller Report'
      AND A.UserField3 = @ReportNum
      AND A.UserField2 <> '9999'
      AND ISNULL(A.UserField5, 'N') = 'N'

The query executes fine.

Answer 1

You need to set the date format explicitly, see https://msdn.microsoft.com/en-us/library/ms189491.aspx

Did the default language change after the upgrade to SQL2008, see

How to change the language and date format in SQL Server?

Answer 2

do a subselect to get the converted date, or an error date if it can't convert and then compare against that

CASE 
WHEN ISDATE(LTRIM(RTRIM(A.UserField1))) = 1 
THEN CONVERT(datetime, LTRIM(RTRIM(A.UserField1))) 
ELSE @ProcessingDate END as convertedDate

and convertedDate < @ProcessingDate

it seems the where clause evaluation order is not specified. so non dates which should be excluded by the other clauses, may be evaluated as dates unless the excusion clause happens to run first

Using case statements with IsDate in a SQL where clause