You get this error in an online page or while running a Application engine program. This error happens when you try to insert more than 254 characters in a long field using sqlexec and do not use %TextIn meta sql.
Use %TextIn meta-sql for the bind variable that is used for inserting into a long field. For e.g. %TextIn(:1)
%TextIn is documented in peoplebooks and is mandatory for all insertions/update of LongChar fields using sqlexec for all database platforms.
Here are some resolutions that discusses this issue in Metalink – Oracle support site.
E-AE Application Engine PeopleCode Step with SQLExec Receives Error; return code 8015 "Bind value is too long" [ID 889806.1]
E-PC:"Bind value is too long" Error When Using SQLExec to Insert into Long Char Field [ID 620874.1]