An expression is a combination of one or more constants, literals, functions, column identifiers and/or variables, separated by operators, that returns a single value. Expressions can be of several types, including arithmetic, relational, logical (or Boolean), and character string. In some Transact-SQL clauses, a subquery can be used in an expression. A case expression can be used in an expression.
Table 4-1 lists the types of expressions that are used in Adaptive Server syntax statements.
Usage |
Definition |
|---|---|
expression |
Can include constants, literals, functions, column identifiers, variables, or parameters |
logical expression |
An expression that returns TRUE, FALSE, or UNKNOWN |
constant expression |
An expression that always returns the same value, such as “5+3” or “ABCDE” |
float_expr |
Any floating-point expression or an expression that implicitly converts to a floating value |
integer_expr |
Any integer expression or an expression that implicitly converts to an integer value |
numeric_expr |
Any numeric expression that returns a single value |
char_expr |
Any expression that returns a single character-type value |
binary_expression |
An expression that returns a single binary or varbinary value |
