Question

有人可以解释为什么下面给我“必须声明标量变量@facilities”。但如果我使用VARCHAR而不是我创建的类型，可以正常工作吗？我该如何解决这个问题？

TIA

--CREATE TYPE integer_list AS TABLE (n int NOT NULL PRIMARY KEY)

--DROP PROCEDURE spTestTVP

CREATE PROCEDURE spTestTVP (
    @facilities integer_list READONLY
    --@facilities varchar(100)
 )
AS
    DECLARE @sql nvarchar(4000)

    SET @sql = 'SELECT * FROM TestTable'

    SET @sql = @sql + ' WHERE 1=1 '

    IF @facilities IS NOT NULL 
        SET @sql = @sql + ' AND (FacilityNo IN (' + @facilities + ') OR FacilityNo IS NULL)'


    EXEC sp_executesql @sql

Answer 1

当您在dynamicSQl语句中连接事物时，构建语句的所有部分必须是varchar或nvarchar。这是SQL的限制。

另一方面，由于您创建了一个表，因此不需要动态sql。

SELECT * FROM TestTable t
LEFT join @facilities f on f.n = t.facilityNO

Answer 2

DECLARE @items VARCHAR(MAX)
SELECT@items = COALESCE(@items+',' ,'') + n
FROM @facilities

DECLARE @sql nvarchar(4000)

    SET @sql = 'SELECT * FROM TestTable'

    SET @sql = @sql + ' WHERE 1=1 '

    IF @facilities IS NOT NULL 
        SET @sql = @sql + ' AND (FacilityNo IN (' + @items + ') OR FacilityNo IS NULL)'


    EXEC sp_executesql @sql

或不动态如下：

SELECT t.* FROM TestTable as t
left outer join
@facilities as f
on
 f.n = t.FacilityNo
where
t.FacilityNo is null
or
f.n is not null

必须使用表值参数和存储过程声明标量变量

2 个答案: