我有一个SQL Server数据库,我想知道它有什么列和类型。我更喜欢通过查询而不是使用像Enterprise Manager这样的GUI来实现这一点。有办法做到这一点吗?


当前回答

我试过了,对我很有效

exec sp_help TABLE_NAME

其他回答

SELECT C.COLUMN_NAME, C.IS_NULLABLE, C.DATA_TYPE, TC.CONSTRAINT_TYPE, C.COLUMN_DEFAULT
    FROM INFORMATION_SCHEMA.COLUMNS AS C
    FULL JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS CC ON C.COLUMN_NAME = CC.COLUMN_NAME 
    FULL JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS TC ON CC.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
WHERE C.TABLE_NAME = '<Table Name>';

样例输出

有几个方法可以获取一个表的元数据:

EXEC sp_help tablename

将返回几个结果集,描述表、它的列和约束。

INFORMATION_SCHEMA视图将为您提供所需的信息,但不幸的是,您必须手动查询这些视图并连接它们。

下面的查询将提供类似于python、Pandas库中的info()函数的输出。

USE [Database_Name]

IF OBJECT_ID('tempdo.dob.#primary_key', 'U') IS NOT NULL DROP TABLE #primary_key

SELECT 
CONS_T.TABLE_CATALOG,
CONS_T.TABLE_SCHEMA,
CONS_T.TABLE_NAME,
CONS_C.COLUMN_NAME,
CONS_T.CONSTRAINT_TYPE,
CONS_T.CONSTRAINT_NAME
INTO  #primary_key
FROM
INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS CONS_T 
JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS CONS_C ON CONS_C.CONSTRAINT_NAME= CONS_T.CONSTRAINT_NAME


SELECT
SMA.name AS [Schema Name],
ST.name AS [Table Name],
SC.column_id AS [Column Order],
SC.name AS [Column Name],
PKT.CONSTRAINT_TYPE, 
PKT.CONSTRAINT_NAME, 
SC.system_type_id,
STP.name AS [Data Type],
SC.max_length,
SC.precision, 
SC.scale, 
SC.is_nullable, 
SC.is_masked
FROM sys.tables  AS ST
JOIN sys.schemas AS SMA ON SMA.schema_id = ST.schema_id
JOIN sys.columns AS SC ON SC.object_id = ST.object_id 
JOIN sys.types AS STP ON STP.system_type_id = SC.system_type_id
LEFT JOIN #primary_key AS PKT ON PKT.TABLE_SCHEMA = SMA.name
                                 AND PKT.TABLE_NAME = ST.name
                                 AND PKT.COLUMN_NAME = SC.name
ORDER BY ST.name ASC, SMA.name ASC

我喜欢这种格式:

name     DataType      Collation             Constraints         PK  FK          Comment

id       int                                 NOT NULL IDENTITY   PK              Order Line Id
pid      int                                 NOT NULL                tbl_orders  Order Id
itemCode varchar(10)   Latin1_General_CI_AS  NOT NULL                            Product Code

所以我用了这个:

DECLARE @tname varchar(100) = 'yourTableName';

SELECT  col.name,

        CASE typ.name
            WHEN 'nvarchar' THEN 'nvarchar('+CAST((col.max_length / 2) as varchar)+')'
            WHEN 'varchar' THEN 'varchar('+CAST(col.max_length as varchar)+')'
            WHEN 'char' THEN 'char('+CAST(col.max_length as varchar)+')'
            WHEN 'nchar' THEN 'nchar('+CAST((col.max_length / 2) as varchar)+')'
            WHEN 'binary' THEN 'binary('+CAST(col.max_length as varchar)+')'
            WHEN 'varbinary' THEN 'varbinary('+CAST(col.max_length as varchar)+')'
            WHEN 'numeric' THEN 'numeric('+CAST(col.precision as varchar)+(CASE WHEN col.scale = 0 THEN '' ELSE ','+CAST(col.scale as varchar) END) +')'
            WHEN 'decimal' THEN 'decimal('+CAST(col.precision as varchar)+(CASE WHEN col.scale = 0 THEN '' ELSE ','+CAST(col.scale as varchar) END) +')'
            ELSE typ.name
            END DataType,

        ISNULL(col.collation_name,'') Collation,

        CASE WHEN col.is_nullable = 0 THEN 'NOT NULL ' ELSE '' END + CASE WHEN col.is_identity = 1 THEN 'IDENTITY' ELSE '' END Constraints,

        ISNULL((SELECT 'PK'
                FROM    sys.key_constraints kc INNER JOIN
                        sys.tables tb ON tb.object_id = kc.parent_object_id INNER JOIN
                        sys.indexes si ON si.name = kc.name INNER JOIN
                        sys.index_columns sic ON sic.index_id = si.index_id AND sic.object_id = si.object_id
                WHERE kc.type = 'PK'
                  AND tb.name = @tname
                  AND sic.column_id = col.column_id),'') PK,

        ISNULL((SELECT (SELECT name FROM sys.tables st WHERE st.object_id = fkc.referenced_object_id)
                FROM    sys.foreign_key_columns fkc INNER JOIN
                        sys.columns c ON c.column_id = fkc.parent_column_id AND fkc.parent_object_id = c.object_id INNER JOIN
                        sys.tables t ON t.object_id = c.object_id
                WHERE t.name = tab.name
                  AND c.name = col.name),'') FK,

        ISNULL((SELECT value
                FROM sys.extended_properties
                WHERE major_id = tab.object_id
                  AND minor_id = col.column_id),'') Comment

FROM sys.columns col INNER JOIN
     sys.tables tab ON tab.object_id = col.object_id INNER JOIN
     sys.types typ ON typ.system_type_id = col.system_type_id
WHERE tab.name = @tname
  AND typ.name != 'sysname'
ORDER BY col.column_id;

use

SELECT COL_LENGTH('tablename', 'colname')

其他的解决方法对我都不起作用。