我需要在SQL server上编写一个查询,以获得特定表中的列列表,其相关数据类型(长度)以及它们是否不为空。我已经做到了这么多。

但现在我还需要得到,在同一个表中,对一个列- TRUE,如果该列是一个主键。

我该怎么做呢?

我的期望输出是:

Column name | Data type | Length | isnull | Pk

当前回答

你可以使用查询:

select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, 
       NUMERIC_PRECISION, DATETIME_PRECISION, 
       IS_NULLABLE 
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='TableName'

以获得除Pk信息之外的所有元数据。

其他回答

SELECT COLUMN_NAME, IS_NULLABLE, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH FROM information_schema.columns WHERE table_name = '<name_of_table_or_view>'

在上面的语句中运行SELECT *,以查看information_schema. schema是什么。列的回报。

这个问题之前已经回答过了- https://stackoverflow.com/a/11268456/6169225

查找数据类型和长度的组合结果,并以“NULL”和“非空”的形式为空。

SELECT c.name AS 'Column Name',
       t.name + '(' + cast(c.max_length as varchar(50)) + ')' As 'DataType',
       case 
         WHEN  c.is_nullable = 0 then 'null' else 'not null'
         END AS 'Constraint'
  FROM sys.columns c
  JOIN sys.types t
    ON c.user_type_id = t.user_type_id
 WHERE c.object_id    = Object_id('TableName')

你会发现结果如下所示。

谢谢你!

这里没有主键,但这可以帮助其他只想拥有一个包含字段名和基本字段属性的表名的用户

USE [**YourDB**]
GO
SELECT tbl.name, fld.[Column Name],fld.[Constraint],fld.DataType 
FROM sys.all_objects as tbl left join 
(SELECT c.OBJECT_ID,  c.name AS 'Column Name',
       t.name + '(' + cast(c.max_length as varchar(50)) + ')' As 'DataType',
       case 
         WHEN  c.is_nullable = 0 then 'null' else 'not null'
         END AS 'Constraint'
  FROM sys.columns c
  JOIN sys.types t
    ON c.user_type_id = t.user_type_id
) as fld on tbl.OBJECT_ID = fld.OBJECT_ID
WHERE ( tbl.[type]='U' and tbl.[is_ms_shipped] = 0)
ORDER BY tbl.[name],fld.[Column Name]
GO

我有点惊讶居然没人提

sp_help 'mytable'

扩展Alex的答案,您可以这样做以获得PK约束

Select C.COLUMN_NAME, C.DATA_TYPE, C.CHARACTER_MAXIMUM_LENGTH, C.NUMERIC_PRECISION, C.IS_NULLABLE, TC.CONSTRAINT_NAME
From INFORMATION_SCHEMA.COLUMNS As C
    Left Join INFORMATION_SCHEMA.TABLE_CONSTRAINTS As TC
      On TC.TABLE_SCHEMA = C.TABLE_SCHEMA
          And TC.TABLE_NAME = C.TABLE_NAME
          And TC.CONSTRAINT_TYPE = 'PRIMARY KEY'
Where C.TABLE_NAME = 'Table'

我一定是错过了您想要一个标记来确定给定的列是否是PK的一部分,而不是PK约束的名称。你可以用:

Select C.COLUMN_NAME, C.DATA_TYPE, C.CHARACTER_MAXIMUM_LENGTH
    , C.NUMERIC_PRECISION, C.NUMERIC_SCALE
    , C.IS_NULLABLE
    , Case When Z.CONSTRAINT_NAME Is Null Then 0 Else 1 End As IsPartOfPrimaryKey
From INFORMATION_SCHEMA.COLUMNS As C
    Outer Apply (
                Select CCU.CONSTRAINT_NAME
                From INFORMATION_SCHEMA.TABLE_CONSTRAINTS As TC
                    Join INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE As CCU
                        On CCU.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
                Where TC.TABLE_SCHEMA = C.TABLE_SCHEMA
                    And TC.TABLE_NAME = C.TABLE_NAME
                    And TC.CONSTRAINT_TYPE = 'PRIMARY KEY'
                    And CCU.COLUMN_NAME = C.COLUMN_NAME
                ) As Z
Where C.TABLE_NAME = 'Table'