TSQL

Question

我的 tsql 数据中有一个 tabletable:

CREATE TABLE dbo.Test
(
     Col nVarChar (50) null
)
GO

然后我执行查询：

Select 
    c.name As Name, ty.name as Type, c.max_length As MaxLenght, c.precision As Precision, c.scale As Scale, c.is_nullable As IsNullable, *
From
    sys.schemas s
    inner join sys.tables t on s.schema_id = t.schema_id
    inner join sys.columns c on t.object_id = c.object_id
    inner join sys.types ty on ty.system_type_id = c.system_type_id
Where
    s.name LIKE 'dbo' AND t.name LIKE 'Test'

问题是……为什么会有Two Rows？！

Answer 1

检查这个：

SELECT ROW_NUMBER() OVER(PARTITION BY system_type_id ORDER BY system_type_id)
      , *
FROM sys.types;

检查第一列的值 >1...

映射到相同 system_type_id 的类型很少。有些名字只是其他东西的别名...

更新

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