关于psql在EXECUTE中使用NEW*

如何解决关于psql在EXECUTE中使用NEW*

我检查了所有与SO有关的问题，但对我的情况没有帮助。 我有2个循环（外部用于表，内部用于列）。表用“ r”表示，列用“ m”表示。在“ m”循环中时，该循环应该将列值发送到要创建的触发函数。当我尝试使用“ NEW.m”（尝试许多不同的格式化尝试）时，编译器始终会出错。 您能对此提出建议吗？ Br

FOR r IN SELECT table_name   FROM information_schema.tables  LOOP 
 FOR m IN SELECT column_name FROM information_schema.columns WHERE (table_name = r.table_name )  LOOP                                                                               
function_name := 'dictionary_functions_foreach_trigger';





   EXECUTE format('CREATE OR REPLACE FUNCTION %s()
   RETURNS trigger AS
   $BODY$
   DECLARE

   BEGIN
        IF NEW.m IS NOT NULL AND NEW.m IN  (SELECT key FROM tableX.tableX_key)       
     THEN  RETURN NEW;
        END IF;
   END;

   $BODY$
   LANGUAGE plpgsql VOLATILE
   COST 100;
   ALTER FUNCTION %s()
   OWNER TO mydb;',function_name,function_name);  



     EXECUTE 'CREATE  TRIGGER ' || function_name || ' BEFORE INSERT OR UPDATE  ON '  || belonging_to_schema || '.' || r.table_name || ' FOR EACH ROW EXECUTE PROCEDURE ' || function_name || '();';

----编辑后的触发功能-

 EXECUTE format(
        
  'CREATE OR REPLACE FUNCTION %s()
   RETURNS trigger AS
   $BODY$
   DECLARE
      insideIs text := %s ;
     
   BEGIN
         
         FOR %s IN 0..(TG_NARGS-1) LOOP
            IF %I= TG_ARGV[%s]
            THEN insideIs := %s ;     
             END IF;
         END LOOP; 
     
     
        IF NEW.%I IS NOT NULL AND   (insideIs =%s) AND  NEW.%I IN  (SELECT key FROM tableX.tableX_key)       
        THEN  RETURN NEW;
        ELSE             RETURN OLD;              
        END IF;
       
     END;
   $BODY$  
  LANGUAGE plpgsql VOLATILE
    COST 100;
   ALTER FUNCTION %s()
   OWNER TO mydb;','notInside','i',m.column_name,'ok',function_name);  

解决方法

您需要使用其他占位符作为列名，就像您写的那样，列名"m"在函数中硬编码。

您实际上也不需要外部循环，因为table_name也可以在information_schema.columns中使用。

如果条件不成立，因为在这种情况下您没有return，则触发器也会因运行时错误而失败。如果要中止该语句，请使用return null;

对于format()语句，您还应该使用create trigger。

FOR m IN SELECT table_schema,table_name,column_name 
         FROM information_schema.columns 
         WHERE table_name in (...) 
LOOP                                                                               
  function_name := 'dictionary_functions_foreach_trigger';
  EXECUTE format('CREATE OR REPLACE FUNCTION %I()
    RETURNS trigger AS
    $BODY$
    DECLARE
    BEGIN
        IF NEW.%I IS NOT NULL AND NEW.%I IN  (SELECT key FROM tableX.tableX_key) THEN  
          RETURN NEW;
        END IF;
        RETURN null; --<< you need some kind of return here!
   END;
   $BODY$
   LANGUAGE plpgsql VOLATILE
   COST 100;
   ALTER FUNCTION %s()
   OWNER TO mydb;',function_name,m.column_name,function_name);  

  EXECUTE format('CREATE TRIGGER %I BEFORE INSERT OR UPDATE ON %I.%I FOR EACH ROW EXECUTE PROCEDURE %I()',m.table_schema,m.table_name,function_name);
END LOOP;   

Online example