SQL Server - 用企业管理器,把INFORMATION_SCHEMA里的东西挨个过一遍
SELECT T.TABLE_NAME AS [Table], C.COLUMN_NAME AS [Column], C.IS_NULLABLE AS [Allows Nulls?], C.DATA_TYPE AS [Type] FROM INFORMATION_SCHEMA.Tables T JOIN INFORMATION_SCHEMA.Columns C ON T.TABLE_NAME = C.TABLE_NAME WHERE T.TABLE_NAME NOT LIKE 'sys%' AND T.TABLE_NAME <> 'dtproperties' AND T.TABLE_SCHEMA <> 'INFORMATION_SCHEMA' ORDER BY T.TABLE_NAME, C.ORDINAL_POSITION
Oracle -查看数据词典时,可以根据需求,选择不同的前缀,然后配合目标内容,如TABLES、COLUMNS、VIEWS等等
USER 前缀
User's view (what is in the user's schema) // 目标范围锁定在当前用户所拥有的对象中
ALL 前缀
Expanded user's view (what the user can access)// 目标范围锁定在当前用户可以访问的对象中
DBA 前缀
Database administrator's view (what is in all users' schemas)// 目标范围锁定在所有用户拥有的对象中
SELECT * FROM USER_OBJECTS; SELECT * FROM USER_TABLES;
DB2 - 想要的东西都可以在Schema SYSCAT中找到
SELECT * FROM SYSCAT.TABLES; SELECT * FROM SYSPUBLIC.DUAL // 这个比较特殊,空表一个,类似于Oracle中的DUAL
DB2可以通过改变DB2_COMPATIBILITY_VECTOR 的设置来启用Oracle兼容模式,这样就可以打开支持PL/SQL的功能,并且能够使用Oracle中提供访问数据词典的表和视图了。
mysql - 东西也是在information_schema中,这个是mysql 5中的新内容
mysql> use information_schema; Database changed mysql> show tables; +---------------------------------------+ | Tables_in_information_schema | +---------------------------------------+ | CHARACTER_SETS | | COLLATIONS | | COLLATION_CHARACTER_SET_APPLICABILITY | | COLUMNS | | COLUMN_PRIVILEGES | | KEY_COLUMN_USAGE | | PROFILING | | ROUTINES | | SCHEMATA | | SCHEMA_PRIVILEGES | | STATISTICS | | TABLES | | TABLE_CONSTRAINTS | | TABLE_PRIVILEGES | | TRIGGERS | | USER_PRIVILEGES | | VIEWS | +---------------------------------------+ 17 rows in set (0.00 sec) mysql>
对于版本 4 来说,可以使用 SHOW 命令(http://dev.mysql.com/doc/refman/4.1/en/show.html)