ACTION
DEFINE ACTION
Specifies a named action that is a parameterizable block of multiple top-level expressions.
Syntax
DEFINE ACTION
: action definition.- Action name that will be used to access the defined action further in the query.
- The values of parameter names are listed in parentheses.
AS
keyword.- List of top-level expressions.
END DEFINE
: The marker of the last expression inside the action.
One or more of the last parameters can be marked with a question mark ?
as optional. If they are omitted during the call, they will be assigned the NULL
value.
DO
Executes an ACTION
with the specified parameters.
Syntax
DO
: Executing an action.- The named expression for which the action is defined.
- The values to be used as parameters are listed in parentheses.
EMPTY_ACTION
: An action that does nothing.
Example
DEFINE ACTION $hello_world($name, $suffix?) AS
$name = $name ?? ($suffix ?? "world");
SELECT "Hello, " || $name || "!";
END DEFINE;
DO EMPTY_ACTION();
DO $hello_world(NULL);
DO $hello_world("John");
DO $hello_world(NULL, "Earth");
BEGIN .. END DO
Performing an action without declaring it (anonymous action).
Syntax
BEGIN
.- List of top-level expressions.
END DO
.
An anonymous action can't include any parameters.
Example
DO BEGIN
SELECT 1;
SELECT 2 -- here and in the previous example, you might omit ';' before END
END DO