如何在SQL Server数据库中列出用户定义的类型？

Question

我需要枚举在SQL Server数据库中创建的所有用户定义类型CREATE TYPE,和/或找出它们是否已经定义.

使用表或存储过程,我会做这样的事情:

if exists (select * from dbo.sysobjects where name='foobar' and xtype='U')
    drop table foobar

但是我找不到用户定义类型的等价物(或合适的替代品)!我绝对不能在任何地方看到它们sysobjects.

任何人都可以开导我吗？

Answer 1

类型和UDT不会出现在sys.objects中.您应该能够通过以下方式获得所需内容:

select * from sys.types
where is_user_defined = 1

Answer 2

虽然帖子很旧,但我发现使用类似的查询很有用.您可能找不到一些有用的格式,但我想要完全限定的类型名称,我希望看到按顺序列出的列.您可以删除所有SUBSTRING内容以仅获取列名称.

SELECT USER_NAME(TYPE.schema_id) + '.' + TYPE.name      AS "Type Name",
       COL.column_id,
       SUBSTRING(CAST(COL.column_id + 100 AS char(3)), 2, 2)  + ': ' + COL.name   AS "Column",
       ST.name                                          AS "Data Type",
       CASE COL.Is_Nullable
       WHEN 1 THEN ''
       ELSE        'NOT NULL' 
       END                                              AS "Nullable",
       COL.max_length                                   AS "Length",
       COL.[precision]                                  AS "Precision",
       COL.scale                                        AS "Scale",
       ST.collation                                     AS "Collation"
FROM sys.table_types TYPE
JOIN sys.columns     COL
    ON TYPE.type_table_object_id = COL.object_id
JOIN sys.systypes AS ST  
    ON ST.xtype = COL.system_type_id
where TYPE.is_user_defined = 1
ORDER BY "Type Name",
         COL.column_id

Answer 3

要扩展 jwolly2 的答案，以下是获取包括标准数据类型的定义列表的方法：

-- User Defined Type definitions TP 20180124
select t1.name, t2.name, t1.precision, t1.scale, t1.max_length as bytes, t1.is_nullable
from sys.types t1
join sys.types t2 on t2.system_type_id = t1.system_type_id and t2.is_user_defined = 0
where t1.is_user_defined = 1 and t2.name <> 'sysname'
order by t1.name