在SQL Server中,“describe table”相当于什么?

412

我有一个SQL Server数据库,想知道它有哪些列和数据类型。我更倾向于通过查询来完成这个任务而不是使用Enterprise Manager等GUI工具。有没有一种方法可以做到这一点?


1
另一个stackoverflow问题已经解答了这个问题。 - Shiva
我不明白为什么微软之前没有放置这个选项。这是必备的功能。 - nomadSK25
24个回答

6
你可以使用 sp_help 'TableName'。它与指定表相关的所有信息都将被返回。

6

试一试:

EXEC [ServerName].[DatabaseName].dbo.sp_columns 'TableName'

你可以获取一些表结构信息,例如:

TABLE_QUALIFIER(表的限定符)、TABLE_OWNER(表所有者)、TABLE_NAME(表名称)、COLUMN_NAME(列名称)、DATA_TYPE(数据类型)、TYPE_NAME(类型名称)...


1
你能否请详细解释一下答案? - Koushik Roy
谢谢提醒,我已经添加了一些解释。 - jiujiu

5
除了上面的问题,如果我们在数据库中有表格,例如db_name.dbo.table_name,我们可以按照以下步骤操作:
  1. 连接到数据库

    USE db_name;

  2. 使用EXEC sp_help命令,并且别忘了将表名作为'dbo.tablename'输入,如果你的模式为dbo

    exec sp_help 'dbo.table_name'

这应该可以解决问题!

4
  1. 首先连接到您的数据库,

使用 DB_name

  1. 然后执行以下命令:

exec sp_help 'Production.Et_Issue'

这里的“production”是模式名称。如果您没有模式,则可以简单地编写sp_help table_name

enter image description here


3
我試過這個方法,對我有用。
exec sp_help TABLE_NAME

2
这是我在 EntityFramework Reverse POCO Generator 中使用的代码(可在 这里 下载)。
表格 SQL:
SELECT  c.TABLE_SCHEMA AS SchemaName,
        c.TABLE_NAME AS TableName,
        t.TABLE_TYPE AS TableType,
        c.ORDINAL_POSITION AS Ordinal,
        c.COLUMN_NAME AS ColumnName,
        CAST(CASE WHEN IS_NULLABLE = 'YES' THEN 1
                  ELSE 0
             END AS BIT) AS IsNullable,
        DATA_TYPE AS TypeName,
        ISNULL(CHARACTER_MAXIMUM_LENGTH, 0) AS [MaxLength],
        CAST(ISNULL(NUMERIC_PRECISION, 0) AS INT) AS [Precision],
        ISNULL(COLUMN_DEFAULT, '') AS [Default],
        CAST(ISNULL(DATETIME_PRECISION, 0) AS INT) AS DateTimePrecision,
        ISNULL(NUMERIC_SCALE, 0) AS Scale,
        CAST(COLUMNPROPERTY(OBJECT_ID(QUOTENAME(c.TABLE_SCHEMA) + '.' + QUOTENAME(c.TABLE_NAME)), c.COLUMN_NAME, 'IsIdentity') AS BIT) AS IsIdentity,
        CAST(CASE WHEN COLUMNPROPERTY(OBJECT_ID(QUOTENAME(c.TABLE_SCHEMA) + '.' + QUOTENAME(c.TABLE_NAME)), c.COLUMN_NAME, 'IsIdentity') = 1 THEN 1
                  WHEN COLUMNPROPERTY(OBJECT_ID(QUOTENAME(c.TABLE_SCHEMA) + '.' + QUOTENAME(c.TABLE_NAME)), c.COLUMN_NAME, 'IsComputed') = 1 THEN 1
                  WHEN DATA_TYPE = 'TIMESTAMP' THEN 1
                  ELSE 0
             END AS BIT) AS IsStoreGenerated,
        CAST(CASE WHEN pk.ORDINAL_POSITION IS NULL THEN 0
                  ELSE 1
             END AS BIT) AS PrimaryKey,
        ISNULL(pk.ORDINAL_POSITION, 0) PrimaryKeyOrdinal,
        CAST(CASE WHEN fk.COLUMN_NAME IS NULL THEN 0
                  ELSE 1
             END AS BIT) AS IsForeignKey
FROM    INFORMATION_SCHEMA.COLUMNS c
        LEFT OUTER JOIN (SELECT u.TABLE_SCHEMA,
                                u.TABLE_NAME,
                                u.COLUMN_NAME,
                                u.ORDINAL_POSITION
                         FROM   INFORMATION_SCHEMA.KEY_COLUMN_USAGE u
                                INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc
                                    ON u.TABLE_SCHEMA = tc.CONSTRAINT_SCHEMA
                                       AND u.TABLE_NAME = tc.TABLE_NAME
                                       AND u.CONSTRAINT_NAME = tc.CONSTRAINT_NAME
                         WHERE  CONSTRAINT_TYPE = 'PRIMARY KEY') pk
            ON c.TABLE_SCHEMA = pk.TABLE_SCHEMA
               AND c.TABLE_NAME = pk.TABLE_NAME
               AND c.COLUMN_NAME = pk.COLUMN_NAME
        LEFT OUTER JOIN (SELECT DISTINCT
                                u.TABLE_SCHEMA,
                                u.TABLE_NAME,
                                u.COLUMN_NAME
                         FROM   INFORMATION_SCHEMA.KEY_COLUMN_USAGE u
                                INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc
                                    ON u.TABLE_SCHEMA = tc.CONSTRAINT_SCHEMA
                                       AND u.TABLE_NAME = tc.TABLE_NAME
                                       AND u.CONSTRAINT_NAME = tc.CONSTRAINT_NAME
                         WHERE  CONSTRAINT_TYPE = 'FOREIGN KEY') fk
            ON c.TABLE_SCHEMA = fk.TABLE_SCHEMA
               AND c.TABLE_NAME = fk.TABLE_NAME
               AND c.COLUMN_NAME = fk.COLUMN_NAME
        INNER JOIN INFORMATION_SCHEMA.TABLES t
            ON c.TABLE_SCHEMA = t.TABLE_SCHEMA
               AND c.TABLE_NAME = t.TABLE_NAME
WHERE c.TABLE_NAME NOT IN ('EdmMetadata', '__MigrationHistory')

外键 SQL:
SELECT  FK.name AS FK_Table,
        FkCol.name AS FK_Column,
        PK.name AS PK_Table,
        PkCol.name AS PK_Column,
        OBJECT_NAME(f.object_id) AS Constraint_Name,
        SCHEMA_NAME(FK.schema_id) AS fkSchema,
        SCHEMA_NAME(PK.schema_id) AS pkSchema,
        PkCol.name AS primarykey,
        k.constraint_column_id AS ORDINAL_POSITION
FROM    sys.objects AS PK
        INNER JOIN sys.foreign_keys AS f
            INNER JOIN sys.foreign_key_columns AS k
                ON k.constraint_object_id = f.object_id
            INNER JOIN sys.indexes AS i
                ON f.referenced_object_id = i.object_id
                   AND f.key_index_id = i.index_id
            ON PK.object_id = f.referenced_object_id
        INNER JOIN sys.objects AS FK
            ON f.parent_object_id = FK.object_id
        INNER JOIN sys.columns AS PkCol
            ON f.referenced_object_id = PkCol.object_id
               AND k.referenced_column_id = PkCol.column_id
        INNER JOIN sys.columns AS FkCol
            ON f.parent_object_id = FkCol.object_id
               AND k.parent_column_id = FkCol.column_id
ORDER BY FK_Table, FK_Column

扩展属性:
SELECT  s.name AS [schema],
        t.name AS [table],
        c.name AS [column],
        value AS [property]
FROM    sys.extended_properties AS ep
        INNER JOIN sys.tables AS t
            ON ep.major_id = t.object_id
        INNER JOIN sys.schemas AS s
            ON s.schema_id = t.schema_id
        INNER JOIN sys.columns AS c
            ON ep.major_id = c.object_id
               AND ep.minor_id = c.column_id
WHERE   class = 1
ORDER BY t.name

2

这些答案的问题在于你缺少关键信息。 虽然有点混乱,但这是我想出来的一个快速版本,以确保它包含与 MySQL Describe 显示相同的信息。

Select SC.name AS 'Field', ISC.DATA_TYPE AS 'Type', ISC.CHARACTER_MAXIMUM_LENGTH AS 'Length', SC.IS_NULLABLE AS 'Null', I.is_primary_key AS 'Key', SC.is_identity AS 'Identity'
From sys.columns AS SC 
LEFT JOIN sys.index_columns AS IC
ON IC.object_id = OBJECT_ID('dbo.Expenses') AND 
IC.column_id = SC.column_id
LEFT JOIN sys.indexes AS I 
ON I.object_id = OBJECT_ID('dbo.Expenses') AND 
IC.index_id = I.index_id
LEFT JOIN information_schema.columns ISC
ON ISC.TABLE_NAME = 'Expenses'
AND ISC.COLUMN_NAME = SC.name
WHERE SC.object_id = OBJECT_ID('dbo.Expenses')

is_primary_key为什么可能没有值? - Michael

2

I like this format:

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

"最初的回答":所以我使用了这个:

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;

1
使用。
SELECT COL_LENGTH('tablename', 'colname')

没有其他解决方案对我有用。


这需要知道其他列是什么。此外,还有一个拼写错误。 - pcnate
修正了引号。 - nikeee

1
只需双击表名,然后按下Alt+F1即可。

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