A delimiter is used to separate the lexical units in the language for compiler processing. Delimiters are either spaces, control characters, comments or special tokens. A comment must be preceded by double hyphens (--).

The following symbols are used as special tokens in SQL:

 

,	()	<	>	.
:	=	+	-	*
<>	<=	>=	/	;
?	~>	~<	~=	"