Text and image functions

For example, use the textptr function to locate the text column, copy, associated with title_id BU7832 in table blurbs. The text pointer, a 16-byte binary string, is put into a local variable, @val, and supplied as a parameter to the readtext command. readtext returns 5 bytes starting at the second byte, with an offset of 1. readtext provides a way to retrieve text, unitext, and image values if you want to retrieve only a portion of a column’s data.

declare @val binary(16) 
select @val = textptr(copy) from blurbs 
where au_id = "486-29-1786" 
readtext blurbs.copy @val 1 5

textptr returns a 16-byte varbinary string. Sybase suggests that you put this string into a local variable, as in the preceding example, and use it by reference.

An alternative to using textptr in the preceding declare example is the @@textptr global variable:

readtext texttest.blurb @@textptr 1 5