MySql:
show full columns from tableName;
Sql server:
SELECT A.name AS table_name, B.name AS column_name, C.value AS column_description FROM sys.tables AS A INNER JOIN sys.columns AS B ON B.object_id = A.object_id LEFT OUTER JOIN sys.extended_properties AS C ON C.major_id = B.object_id AND C.minor_id = B.column_id WHERE (A.name = '表名')