VFP has a limit of 255 characters per string literal. You can split it in the shorter parts and join them with '+' operator. The limit on the size of string variable (according to the help) is 16,777,184 characters.

MySele = "12345678901234567890123456789012345678901234567890" + ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890" +  ;
  "12345678901234567890123456789012345678901234567890"

>I am working in Visual Foxpro 6.
>
>1-. if i want to use SQLEXEC and my SQL sentence is to some extend,
> Visual Foxpro send me one error relation with string too longe. so
> that, can't work with sentence SQL Large, and this is my case.
> example:
>
>
< snip >