private static string sql = @"SELECT Sysobjects.name AS TABLE_NAME, syscolumns.Id, syscolumns.name AS COLUMN_NAME,
systypes.name AS DATA_TYPE, syscolumns.length as CHARACTER_MAXIMUM_LENGTH,
sys.extended_properties.[value] AS COLUMN_DESCRIPTION,  syscomments.text as
COLUMN_DEFAULT,syscolumns.isnullable as IS_NULLABLE FROM syscolumns
INNER JOIN systypes
    ON syscolumns.xtype = systypes.xtype
    LEFT JOIN sysobjects ON syscolumns.id = sysobjects.id
   LEFT OUTER JOIN sys.extended_properties ON
   ( sys.extended_properties.minor_id = syscolumns.colid
     AND sys.extended_properties.major_id = syscolumns.id)
   LEFT OUTER JOIN syscomments ON syscolumns.cdefault = syscomments.id
   WHERE syscolumns.id IN 
    (SELECT id FROM SYSOBJECTS WHERE xtype = 'U') AND (systypes.name <> 'sysname')
    ORDER BY syscolumns.colid";

 private static string sql = @"SELECT Sysobjects.name AS TABLE_NAME, syscolumns.Id, syscolumns.name AS COLUMN_NAME,
systypes.name AS DATA_TYPE, syscolumns.length as CHARACTER_MAXIMUM_LENGTH,
sys.extended_properties.[value] AS COLUMN_DESCRIPTION,  syscomments.text as
COLUMN_DEFAULT,syscolumns.isnullable as IS_NULLABLE FROM syscolumns
INNER JOIN systypes
    ON syscolumns.xtype = systypes.xtype
    LEFT JOIN sysobjects ON syscolumns.id = sysobjects.id
   LEFT OUTER JOIN sys.extended_properties ON
   ( sys.extended_properties.minor_id = syscolumns.colid
     AND sys.extended_properties.major_id = syscolumns.id)
   LEFT OUTER JOIN syscomments ON syscolumns.cdefault = syscomments.id
   WHERE syscolumns.id IN 
    (SELECT id FROM SYSOBJECTS WHERE xtype = 'U') AND (systypes.name <> 'sysname')
    ORDER BY syscolumns.colid";