14.5.3 SET 和 SHOW 语法
SET 可以用于设置各种变量或者选项。
SHOW 可以以各种形式描述数据库系统的信息，诸如数据表，字段，服务器状态等等。大致有以下这些方法：
SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [LIKE ‘pattern’]
SHOW CREATE DATABASE db_name
SHOW CREATE TABLE tbl_name
SHOW DATABASES [LIKE ‘pattern’]
SHOW [STORAGE] ENGINES
SHOW ERRORS [LIMIT [offset,] row_count]
SHOW GRANTS FOR user
SHOW INDEX FROM tbl_name [FROM db_name]
SHOW INNODB STATUS
SHOW [BDB] LOGS
SHOW PRIVILEGES
SHOW [FULL] PROCESSLIST
SHOW STATUS [LIKE ‘pattern’]
SHOW TABLE STATUS [FROM db_name] [LIKE ‘pattern’]
SHOW [OPEN] TABLES [FROM db_name] [LIKE ‘pattern’]
SHOW [GLOBAL | SESSION] VARIABLES [LIKE ‘pattern’]
SHOW WARNINGS [LIMIT [offset,] row_count]
SHOW CREATE DATABASE db_name
SHOW CREATE TABLE tbl_name
SHOW DATABASES [LIKE ‘pattern’]
SHOW [STORAGE] ENGINES
SHOW ERRORS [LIMIT [offset,] row_count]
SHOW GRANTS FOR user
SHOW INDEX FROM tbl_name [FROM db_name]
SHOW INNODB STATUS
SHOW [BDB] LOGS
SHOW PRIVILEGES
SHOW [FULL] PROCESSLIST
SHOW STATUS [LIKE ‘pattern’]
SHOW TABLE STATUS [FROM db_name] [LIKE ‘pattern’]
SHOW [OPEN] TABLES [FROM db_name] [LIKE ‘pattern’]
SHOW [GLOBAL | SESSION] VARIABLES [LIKE ‘pattern’]
SHOW WARNINGS [LIMIT [offset,] row_count]
如果 SHOW 语法中包括 LIKE ‘pattern’ 分句的话，’pattern’ 是一个可以包括 SQL 语法中‘ % ‘和‘ _ ‘等通配符的字符串。这个模式语句对于取得相应的结果十分有用。 继续阅读