sql-input-ring-separator

sql-input-ring-separator is a variable defined in `sql.el'.
Its value is

"
--
"

Documentation:
Separator between commands in the history file.

If set to "\n", each line in the history file will be interpreted as
one command. Multi-line commands are split into several commands when
the input ring is initialized from a history file.

This variable used to initialize `comint-input-ring-separator'.
`comint-input-ring-separator' is part of Emacs 21; if your Emacs
does not have it, setting `sql-input-ring-separator' will have no
effect. In that case multiline commands will be split into several
commands when the input history is read, as if you had set
`sql-input-ring-separator' to "\n".

You can customize this variable.