function - 如何在 PostgreSQL 函数的插入查询中插入参数值？

Question

我在 PostgreSQL 中编写了一个带有参数的函数，我想将参数值插入到数据库表中。脚本执行正常，但是当我调用该函数时，我收到一条错误消息:

CREATE OR REPLACE FUNCTION sp_load_purchase_order(x int)
  RETURNS void AS
$$ 
declare var_val char;
begin

var_val='p'+i;
insert into purchase_order(
create_uid, 
   create_date, 
   write_date, 
   write_uid, 
   journal_id, 
   date_order, 
   partner_id, 
   amount_untaxed, 
   location_id, 
   company_id, 
   amount_tax, 
   state, 
   pricelist_id, 
   warehouse_id, 
   payment_term_id, 
   amount_total, 
   name, 
   invoice_method, 
   shipped, 
   minimum_planned_date
) 
values(1,now(),now(),1,13,now(),17,1.00,12,1,0.00,'draft',2,1,3,1.00
      ,var_val,'order','f' ,now()
);

end;
$$
  LANGUAGE 'plpgsql';

错误信息:

ERROR:  column "i" does not exist
LINE 1: SELECT 'p'+i
                   ^
QUERY:  SELECT 'p'+i
CONTEXT:  PL/pgSQL function sp_load_purchase_order(integer) line 5 at assignment

********** Error **********

ERROR: column "i" does not exist
SQL state: 42703
Context: PL/pgSQL function sp_load_purchase_order(integer) line 5 at assignment

请帮我指出问题

Answer 1

而plpgsql中的赋值运算符是:=:
The forgotten assignment operator "=" and the commonplace ":="

不要引用语言名称plpgsql!

而且您不需要为此声明变量。连接可以发生在 INSERT 语句中，这样成本更低。

CREATE OR REPLACE FUNCTION sp_load_purchase_order(x int)
  RETURNS void AS
$func$ 
begin

insert into purchase_order(create_uid, ..., name, ...) 
values(1, ..., 'p' || x, ...);

end
$func$  LANGUAGE plpgsql;