Configure Operators or Functions

On the Operators and Functions subtabs, you can add, remove, define and modify the expressions (signatures) and data types of functions or operators (either existing or custom) for new data source instances.

Throughout these subtabs, use the notation $1, $2, and so on, to indicate the first (arg1), second (arg2), and subsequent arguments.

Default Native Expression

Type a representative syntax for the expression as it is to be pushed to the data source. This syntax is a combination of argument notation and the characters that make up the operator or function name. For examples, examine some existing native expressions (like “$1 > $2”) in the user interface.

Add a Variation

Right below Default native expression is a field labeled Add <property_name> variation with number of arguments. Specify the number of arguments (up to 100) and click the Add button. A new argument combination (argument data types and native expression) is displayed at the top of the Argument combinations list for this property.

Argument Data Types

Type a data type, or a comma-separated list of data types, for each argument. You must use the prefix cis. or native. before each data type name to remove ambiguity. For a list all TDV data type names, see Data Type Naming.

Arguments are numbered by their position in each specific argument combination. For example, $2 in one native expression is not necessarily the same as $2 in another native expression.

Native Expression

You need to specify a new native expression if:

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An argument combination uses a different number or ordering of arguments than the default native expression.

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Behavior differs from the SQL standard, such as for a NULL argument, and so you need to map the function combination to something that would give an expected result. That result could be a literal, a CASE IF ELSE statement, or a different function altogether.