pgsql 存儲過程初識

表T1 {

id bigint primary key;

t2_id bigint ;

}

表T2 {

id bigint primary key;

path not null;

}

其中T1的字段 t2_id 是T2 的外鍵 

刪除T1 中某條記錄時，若T2中有相應記錄，則返回其path值 ； 若無相應 T2 記錄，則返回null；

實現的存儲過程以下create or replace function test( tid bigint) returns varchar as$$         declare    cursor1 refcursor;    result varchar;begin    select t1.t2_id from T t1 where t1.id = tid into result;    if  result is null  then        raise notice '11';        open cursor1 for delete from T1 t1 where t1.id = tid returning null as path;        fetch cursor1 into result;        return result;    else        raise notice '22';        open cursor1 for delete from T1 t1 using T2 t2 where t1.id = tid and t1.t2_id = t2.id returning t2.path as path;        fetch cursor1 into result;        return result;    end if;end$$language plpgsql;