In SQL Query Builder, you can use build expressions of these types when creating SQL statements.
Table 1. Expression types
||A function returns a value.
Functions types include column functions, scalar
functions, row functions, or table functions.
The argument of a column function is a collection of like
values (a column). This function can return a NULL value.
The argument(s) of a scalar function are individual scalar
values, which can be of different types. This function can return a NULL value.
The argument of a row function is a structured type. The
function returns a row of built-in data types and can only be
specified as a transform function for a structured type.
The argument(s) of a table function are individual scalar
values, which can be of different types. The function returns a
table, and can be specified only within the FROM clause of a SELECT
|| CASE expressions allow an expression to be selected based on the evaluation of one or more conditions. A CASE expression contains one or more when clauses of either Search or Simple type.
A Search CASE expression contains a condition that is evaluated, such as i<8.
A Simple CASE expression determines if the when clause evaluates to true; otherwise, the else clause determines the value of the case-expression.
||A CAST function converts instances of a datatype to
instances of a different datatype.
|| A constant specifies a value: a string or a number.
Numeric constants can be an integer, floating-point, or decimal.
A string constant can be a character string, hexadecimal, or a host variable name. A colon precedes the host variable name, for example, :var. The host variable becomes a value when the statement is executed.
||A subquery is a SELECT, WITH, or FULLSELECT statement nested within
another SQL statement. The expression value is the result of the
|Build up expressions by operators
||You can build an expression by applying operators to columns or expressions such as x+y where x is a column and y is an expression.