MySQL

Declarations must follow a certain order. Cursors must be declared before declaring handlers, and variables and conditions must be declared before declaring either cursors or handlers.

DECLARE is allowed only inside a BEGIN ... END compound statement and must be at its start, before any other statements.

Each parameter is an IN parameter by default. To specify otherwise for a parameter, use the keyword OUT or INOUT before the parameter name.

Specifying a parameter as IN, OUT, or INOUT is valid only for a PROCEDURE. (FUNCTION parameters are always regarded as IN parameters.)