在数据库中,我有一个名为SERVICE的表。对于这个表,我在INSER/UPDATE/DELETE之后有触发器。当我尝试使用EF将记录插入数据库时,会出现错误"元数据集合中不存在标识为'component_type_name'的成员。\r\n参数名称:identity"。列"component_type_name"不存在于SERVICE表中,但存在于component_TYPES_in_SERVICE表中。这是SERVICE表的插入触发器。当我从表中删除触发器时,插入不会有任何问题。
CREATE TRIGGER [dbo].[UpdateComponentTypesInServiceOnInsert]
ON [dbo].[SERVICE]
AFTER INSERT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE @componentID int;
SET @componentID = 0;
DECLARE @ComponentTypeID int;
SET @ComponentTypeID = 0;
DECLARE @ComponentTypeName nvarchar(255);
SET @ComponentTypeName = null;
SELECT @componentID = component_id from inserted;
SELECT @ComponentTypeID = c.component_type_id, @ComponentTypeName = ct.description from COMPONENTS c
inner join dbo.COMPONENT_TYPES ct on c.component_type_id = ct.id
WHERE c.id = @componentID;
Select * from COMPONENT_TYPES_IN_SERVICE cts
where cts.id = @ComponentTypeID;
IF (@@ROWCOUNT > 0)
BEGIN
UPDATE COMPONENT_TYPES_IN_SERVICE
SET number_of_components = number_of_components + 1
WHERE id = @ComponentTypeID;
END
ELSE
BEGIN
INSERT INTO COMPONENT_TYPES_IN_SERVICE(id, component_type_name, number_of_components)
VALUES (@ComponentTypeID, @ComponentTypeName, 1);
END
END
有人知道解决方案吗???
您不能这样做:
Select * from COMPONENT_TYPES_IN_SERVICE cts
where cts.id = @ComponentTypeID;
它将COMPONENT_TYPES_IN_SERVICE
记录返回给您的应用程序,EF尝试将返回的值复制到SERVICE
中,因为它认为您正在返回一些数据库生成的值。
使用实体框架时,触发器中不能有任何返回值的select语句
在大多数情况下,这种不熟悉错误的确切原因是在使用实体框架时触发器中存在SELECT
语句。删除它们将很有可能修复错误。