查询表结构

方法一
SELECT
   序号=C.column_id,
    列名=C.name,
    是否主键=ISNULL(IDX.PrimaryKey,N''),
    数据类型=T.name,
    长度=C.max_length,
    Precision=C.precision,
    小数位=C.scale,
    允许空=CASE WHEN C.is_nullable=1 THEN N'是'ELSE N'否' END,
    默认值=ISNULL(D.definition,N''),
    说明=ISNULL(PFD.[value],N'')
FROM sys.columns C
    INNER JOIN sys.objects O
        ON C.[object_id]=O.[object_id]
            AND O.type='U'
            AND O.is_ms_shipped=0
    INNER JOIN sys.types T
        ON C.user_type_id=T.user_type_id
    LEFT JOIN sys.default_constraints D
        ON C.[object_id]=D.parent_object_id
            AND C.column_id=D.parent_column_id
            AND C.default_object_id=D.[object_id]
    LEFT JOIN sys.extended_properties PFD
        ON PFD.class=1
            AND C.[object_id]=PFD.major_id
            AND C.column_id=PFD.minor_id
    LEFT JOIN sys.extended_properties PTB
        ON PTB.class=1
            AND PTB.minor_id=0
            AND C.[object_id]=PTB.major_id
    LEFT JOIN                       -- 索引及主键信息
    (
        SELECT
            IDXC.[object_id],
            IDXC.column_id,
            Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending')
                WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END,
            PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N'是'ELSE N'否' END,
            IndexName=IDX.Name
        FROM sys.indexes IDX
        INNER JOIN sys.index_columns IDXC
            ON IDX.[object_id]=IDXC.[object_id]
                AND IDX.index_id=IDXC.index_id
        LEFT JOIN sys.key_constraints KC
            ON IDX.[object_id]=KC.[parent_object_id]
                AND IDX.index_id=KC.unique_index_id
        INNER JOIN  -- 对于一个列包含多个索引的情况,只显示第1个索引信息
        (
            SELECT [object_id], Column_id, index_id=MIN(index_id)
            FROM sys.index_columns
            GROUP BY [object_id], Column_id
        ) IDXCUQ
            ON IDXC.[object_id]=IDXCUQ.[object_id]
                AND IDXC.Column_id=IDXCUQ.Column_id
                AND IDXC.index_id=IDXCUQ.index_id
    ) IDX
        ON C.[object_id]=IDX.[object_id]
            AND C.column_id=IDX.column_id
WHERE C.object_id= object_id('dbo.CRM_商店')       -- 指定表
ORDER BY O.name,C.column_id

方法二
SELECT S.name    ColumName
                      ,(
                       CASE
                        WHEN S.is_nullable=1 THEN N'是'
                        ELSE N'否' END
                      ) AS    AllowNULL
                      ,S.max_length  MaxLength
                      ,TYPESYSTABLE.name DateType
                    FROM sys.Columns S
                     INNER JOIN sys.types TYPESYSTABLE ON S.system_type_id = TYPESYSTABLE.system_type_id
                    WHERE S.object_id= object_id(@TableName)
   AND TYPESYSTABLE.name != 'sysname'
方法三（优化方法一）

                    SELECT  S.column_id     序号
       ,S.name      列名称
       ,ISNULL(IDX.PrimaryKey,N'否') 主键
                      ,(
                       CASE
                        WHEN S.is_nullable=1 THEN N'是'
                        ELSE N'否'
                        END
                      ) AS      是否允许空
                      ,S.max_length    长度
                      ,TYPESYSTABLE.name   数据类型
                      ,S.scale     小数位
                      ,ISNULL(D.definition,N'') 默认值
                      ,ISNULL(PFD.[value],N'') 说明
                    FROM sys.Columns S
                     INNER JOIN sys.types TYPESYSTABLE ON S.system_type_id = TYPESYSTABLE.system_type_id
                     INNER JOIN sys.objects O ON S.[object_id]=O.[object_id]
             AND O.type='U'
             AND O.is_ms_shipped=0
      LEFT JOIN sys.default_constraints D ON S.[object_id]=D.parent_object_id
             AND S.column_id=D.parent_column_id
             AND S.default_object_id=D.[object_id]
      LEFT JOIN sys.extended_properties PFD ON PFD.class=1
             AND S.[object_id]=PFD.major_id
             AND S.column_id=PFD.minor_id
      LEFT JOIN                       -- 索引及主键信息
       (   SELECT
         IDXC.[object_id],
         IDXC.column_id,
         Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending')
          WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END,
         PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N'是'ELSE N'否' END,
         IndexName=IDX.Name
        FROM sys.indexes IDX
         INNER JOIN sys.index_columns IDXC ON IDX.[object_id]=IDXC.[object_id]
                  AND IDX.index_id=IDXC.index_id
         LEFT JOIN sys.key_constraints KC ON IDX.[object_id]=KC.[parent_object_id]
                  AND IDX.index_id=KC.unique_index_id
         INNER JOIN  -- 对于一个列包含多个索引的情况,只显示第1个索引信息
          ( 
           SELECT [object_id], Column_id, index_id=MIN(index_id)
           FROM sys.index_columns
           GROUP BY [object_id], Column_id
          ) IDXCUQ ON IDXC.[object_id]=IDXCUQ.[object_id]
           AND IDXC.Column_id=IDXCUQ.Column_id
           AND IDXC.index_id=IDXCUQ.index_id
        ) IDX ON S.[object_id]=IDX.[object_id]
          AND S.column_id=IDX.column_id
                    WHERE S.object_id= object_id('CRM_商店')
      AND TYPESYSTABLE.name != 'sysname'
     ORDER BY O.name, S.column_id