Postgres function parameter is null then replace it with default value-CodePudding

I have a postgres function

 create or replace function start_batch(in start_date date, int end_date date) returns integer 
as $batch$

BEGIN
    
    if(start_date is null or end_date is null) then
           start_date = date_trunc('month',now())-interval '1 month')::date ;
            end_date = date_trunc('month'now())-interval '1 day')::date;
        end if;
    
    
END;
$bach$ language plpgsql;

but i get syntax error SQL errir [42704] ERROR: unrecognized exception condition "is null" is there any other way to check if in parameter date is null and replace it with default date

CodePudding user response：

You have many incorrect syntaxes here.

Sample for you, this is working:

CREATE OR REPLACE FUNCTION test(start_date date)
 RETURNS date
 LANGUAGE plpgsql
AS $function$
begin
    
    if (start_date is null) then 
    start_date = date_trunc('month', now() - interval '1 month')::date;
    end if; 

    return start_date;
    
end ;
$function$
;

select test(null)

-- Result: 
2022-11-01