Predicates

In our simplified BNF, predicate can be defined as a statement that can be evaluated to either TRUE or FALSE. Table H-2 "decodes" SQL syntax for predicates.

Table H-2: Predicates

Element	Syntax
<predicate>	<boolean_term> [{AND | OR} <boolean_term>,...]
<boolean_term>	[NOT] <search_test>
<search_test>	<comparison_test> | <between_test> | <in_test> | <like_test> | <null_test> | <exists_test> | <quantified_comparisson_test>
<comparison_test>	<column_value> {= | <> | != | < | > | <= | >=} {<expression> | <single_row_subquery>}
<between_test>	<column_value> [NOT] BETWEEN <expression> AND <expression>
<in_test>	<column_value> [NOT] IN <expression_list> | <table_subquery>
<like_test>	<column_value> [NOT] LIKE <pattern> [ESCAPE <value>]
<null_test>	<column_value> IS [NOT] NULL
<exists_test>	EXISTS <table_subquery>
<quantified_ comparisson_test>	<column_value> {= | <> | != | < | > | <= | >=} {ALL | SOME | ANY} <table_subquery>
<expression_list>	(<expression>,...)
<expression>	<sub-expression> {+ | - | * | /} <sub-expression>
<sub-expression>	[- | +] {<value> | <function>}
<value>	<literal> | <variable>
<column_value>	[qualifier.]<column_name>