常見管理MySQL的命令
使用Mysql數據庫過程中常用的命令：
USE 數據庫名 :
選擇要操作的Mysql數據庫，使用該命令後所有Mysql命令都只針對該數據庫。
mysql> use School;
Database changed
SHOW DATABASES:
列出 MySQL 數據庫管理系統的數據庫列表。
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema | |
| mysql |
| onethink |
| performance_schema |
| phpmyadmin |
| test |
| wecenter |
| wordpress |
+--------------------+
10 rows in set (0.02 sec)
SHOW TABLES:
顯示指定數據庫的所有表，使用該命令前需要使用 use 命令來選擇要操作的數據庫。
mysql> use School;
Database changed
mysql> SHOW TABLES;
+------------------+
| Tables_in_School |
+------------------+
| employee_tbl |
| student_tbl |
| tcount_tbl |
+------------------+
3 rows in set (0.00 sec)
SHOW COLUMNS FROM 數據表:
顯示數據表的屬性，屬性類型，主鍵信息 ，是否爲 NULL，默認值等其他信息。
mysql> SHOW COLUMNS FROM student_tbl;
+-----------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+--------------+------+-----+---------+-------+
| student_id | int(11) | NO | PRI | NULL | |
| student_title | varchar(255) | YES | | NULL | |
|+-----------------+--------------+------+-----+---------+-------+
2 rows in set (0.01 sec)
SHOW INDEX FROM 數據表:
顯示數據表的詳細索引信息，包括PRIMARY KEY（主鍵）。
mysql> SHOW INDEX FROM case_tbl;
+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| case_tbl | 0 | PRIMARY | 1 | case_id | A | 2 | NULL | NULL | | BTREE | | |
+------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
1 row in set (0.00 sec)
SHOW TABLE STATUS LIKE [FROM db_name] [LIKE 'pattern'] \G:
該命令將輸出Mysql數據庫管理系統的性能及統計信息。
mysql> SHOW TABLE STATUS FROM SCHOOL; # 顯示數據庫 SCHOOL 中所有表的信息
mysql> SHOW TABLE STATUS from SCHOOL LIKE 'student%'; # 表名以student開頭的表的信息
mysql> SHOW TABLE STATUS from SCHOOL LIKE 'student%'\G; # 加上 \G，查詢結果按列打印