INF: Finding Length of SQL IMAGE Fields While Using DB-Library

ID: Q63605

The information in this article applies to:

Microsoft SQL Server Programmer's Toolkit, version 4.2

SUMMARY

The following information discusses how to find the length of an IMAGE field using DB-Library (DB-Lib) or the datalength() function.

MORE INFORMATION

DB-Library does not support huge pointers; therefore, no single data block can be larger than 64K. For image data less than 64K, the DBDATLEN() command returns the correct size (if TEXTSIZE is set to 64K). Otherwise, a query to SQL Server using the datalength() function is the best method to use to retrieve this information. For example:


   select datalength(Imagecolum) from Imagetable where
   Fname = "MARTIAN.BMP"

The DBDATLEN() command returns the minimum of the actual data length of the image field or the TEXTSIZE as set by the SET TEXTSIZE command.

Additional query words: dblib Transact-SQL

Keywords : kbprg SSrvDB_Lib
Version : 4.2
Platform : OS/2
Issue type :