如何在SQL Server 2008中检查用户定义表类型的存在？

Question

I have a user-defined table type. I want to check it's existence before editing in a patch using OBJECT_ID(name, type) function.

What type from the enumeration should be passed for user-defined table types?

N'U' like for user defined table doesn't work, ie IF OBJECT_ID(N'MyType', N'U') IS NOT NULL

Answer 1

You can look in sys.types or use TYPE_ID:

IF TYPE_ID(N'MyType') IS NULL ...

Just a precaution: using type_id won't verify that the type is a table type--just that a type by that name exists. Otherwise gbn's query is probably better.

Answer 2

IF EXISTS (SELECT * FROM sys.types WHERE is_table_type = 1 AND name = 'MyType')
    --stuff

sys.types ... they aren't schema-scoped objects so won't be in sys.objects

Update, Mar 2013

You can use TYPE_ID too

Answer 3

IF EXISTS(SELECT 1 FROM sys.types WHERE name = 'Person' AND is_table_type = 1 AND SCHEMA_ID('VAB') = schema_id)
DROP TYPE VAB.Person;
go
CREATE TYPE VAB.Person AS TABLE
(    PersonID               INT
    ,FirstName              VARCHAR(255)
    ,MiddleName             VARCHAR(255)
    ,LastName               VARCHAR(255)
    ,PreferredName          VARCHAR(255)
);

Answer 4

Following examples work for me, please note "is_user_defined" NOT "is_table_type"

IF TYPE_ID(N'idType') IS NULL
CREATE TYPE [dbo].[idType] FROM Bigint NOT NULL
go

IF not EXISTS (SELECT * FROM sys.types WHERE is_user_defined = 1 AND name = 'idType')
CREATE TYPE [dbo].[idType] FROM Bigint NOT NULL
go

Answer 5

You can use also system table_types view

IF EXISTS (SELECT *
           FROM   [sys].[table_types]
           WHERE  user_type_id = Type_id(N'[dbo].[UdTableType]'))
  BEGIN
      PRINT 'EXISTS'
  END