如何在SQL Server数据库中列出用户定义的类型?

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的内容:

select * from sys.types
where is_user_defined = 1

虽然这篇文章很旧,但我发现使用类似这样的查询很有用。 您可能不会发现某些格式有用,但我需要完全限定的类型名,并且希望看到按顺序列出的列。您只需删除所有子字符串内容,就可以自己获取列名。

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

要扩展Jwolly2的答案,下面是如何获得包括标准数据类型在内的定义列表:

-- 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