为了确保获得正确的长度，需要将unicode类型视为一种特殊情况。参见下面的代码。

更多信息请参见:https://msdn.microsoft.com/en-us/library/ms176106.aspx

SELECT 
   c.name 'Column Name',
   t.name,
   t.name +
   CASE WHEN t.name IN ('char', 'varchar','nchar','nvarchar') THEN '('+

             CASE WHEN c.max_length=-1 THEN 'MAX'

                  ELSE CONVERT(VARCHAR(4),

                               CASE WHEN t.name IN ('nchar','nvarchar')

                               THEN  c.max_length/2 ELSE c.max_length END )

                  END +')'

          WHEN t.name IN ('decimal','numeric')

                  THEN '('+ CONVERT(VARCHAR(4),c.precision)+','

                          + CONVERT(VARCHAR(4),c.Scale)+')'

                  ELSE '' END

   as "DDL name",
   c.max_length 'Max Length in Bytes',
   c.precision ,
   c.scale ,
   c.is_nullable,
   ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM    
   sys.columns c
INNER JOIN 
   sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN 
   sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN 
   sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
   c.object_id = OBJECT_ID('YourTableName')

SELECT  
   T.NAME AS [TABLE NAME]
   ,C.NAME AS [COLUMN NAME]
   ,P.NAME AS [DATA TYPE]
   ,P.MAX_LENGTH AS [Max_SIZE]
   ,C.[max_length] AS [ActualSizeUsed]
   ,CAST(P.PRECISION AS VARCHAR) +'/'+ CAST(P.SCALE AS VARCHAR) AS [PRECISION/SCALE]
FROM SYS.OBJECTS AS T
JOIN SYS.COLUMNS AS C
    ON T.OBJECT_ID = C.OBJECT_ID
JOIN SYS.TYPES AS P
    ON C.SYSTEM_TYPE_ID = P.SYSTEM_TYPE_ID
    AND C.[user_type_id] = P.[user_type_id]
WHERE T.TYPE_DESC='USER_TABLE'
  AND T.name = 'InventoryStatus'
ORDER BY 2

为了避免某些列的重复行，请使用user_type_id而不是system_type_id。

SELECT 
    c.name 'Column Name',
    t.Name 'Data type',
    c.max_length 'Max Length',
    c.precision ,
    c.scale ,
    c.is_nullable,
    ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM    
    sys.columns c
INNER JOIN 
    sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN 
    sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN 
    sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
    c.object_id = OBJECT_ID('YourTableName')

只需将YourTableName替换为实际的表名-适用于SQL Server 2005及更高版本。

如果您正在使用模式，请将YourTableName替换为YourSchemaName。YourTableName，其中YourSchemaName是实际的模式名，YourTableName是实际的表名。

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。

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！

存储过程sp_columns返回详细的表信息。

exec sp_columns MyTable