Question

我在SQL Server中有一个过程如下：

我正在尝试编写一个与上面完全相同的postgresql函数。我试过这样的事情：

CREATE OR REPLACE FUNCTION getadmbyyear(IN a integer, IN b character varying)
  RETURNS TABLE(monname character varying, mon integer, adm integer, selected integer) AS
$BODY$

DECLARE testtypeid int;

select top 1 testtypeid := typeid from Reports_ReportMenu
where ID = $2

select MonName,Mon,Adm,
case when ROW_NUMBER() OVER(ORDER BY Mon,Adm) = '1' then
cast(1 as int) else cast(0 as int) end as Selected 
from eivTestAdms
where test_type_id=testtypeid and "YR"=$1 and Adm is not null
order by Mon,Adm

$BODY$
 LANGUAGE sql;

这里我在int的declare语句中遇到语法错误。我是以正确的格式编写函数吗？

Answer 1

您无法在SQL函数中使用变量，这些变量仅在使用PL / pgSQL时可用。

但无论如何都不需要这个变量。你可以把它放到一个子选择中。

另外cast(1 as int)没用。 1已经是一个整数，0也是如此，因此不需要进行转换。

CREATE OR REPLACE FUNCTION getadmbyyear(IN a integer, IN b character varying)
  RETURNS TABLE(monname character varying, mon integer, adm integer, selected integer) 
AS
$body$
    select MonName, 
           Mon,
           Adm,
           case 
              when ROW_NUMBER() OVER (ORDER BY Mon,Adm) = 1 then 1 
              else 0 
           end as Selected 
    from eivTestAdms
    where test_type_id = (select testtypeid 
                          from Reports_ReportMenu 
                          where ID = $2
                          limit 1)
     and "YR"=$1 
     and Adm is not null
    order by Mon,Adm;
$body$
language sql;

但SQL Server的bit数据类型通常用作穷人的布尔值。所以它应该是Postgres中真正的boolean。这使得案例陈述更短：

    select MonName, 
           Mon,
           Adm,
           ROW_NUMBER() OVER (ORDER BY Mon,Adm) = 1 as selected -- this is a boolean expression that will return true or false
    from eivTestAdms

然后，您需要将功能签名调整为：

RETURNS TABLE(monname character varying, mon integer, adm integer, selected boolean)

来自SQL Server存储过程的Postgresql函数

1 个答案: