【PHP学习】常用sql语句整理
增
增加一张表
CREATE TABLE `table_name`( ... )ENGINE=InnoDB DEFAULT CHARSET=utf8;
增加记录
INSERT INTO `your_table_name`(`column_name`) VALUES ('your_value_one'), ('your_value_two');
增加字段
ALTER TABLE `your_table_name` ADD `your_column_name` ... AFTER `column_name`;
增加索引
主键
ALTER TABLE `your_table_name` ADD PRIMARY KEY your_index_name(your_column_name);
唯一索引
ALTER TABLE `your_table_name` ADD UNIQUE your_index_name(your_column_name);
普通索引
ALTER TABLE `your_table_name` ADD INDEX your_index_name(your_column_name);
全文索引
ALTER TABLE `your_table_name` ADD FULLTEXT your_index_name(your_column_name);
删
逐行删除
DELETE FORM `table_name` WHERE ...;
清空整张表
TRUNCATE TABLE `your_table_name`;
删除表
DROP TABLE `your_table_name`;
删除字段
ALTER TABLE `your_table_name` DROP `column_name`;
删除索引
ALTER TABLE `your_table_name` DROP INDEX your_index_name(your_column_name);
改
变更数据
UPDATE `table_name` SET column_name=your_value WHERE ...;
变更字段
ALTER TABLE `your_table_name` CHANGE `your_column_name` `your_column_name` ...(变更);
变更字段值为另一张表的某个值
UPDATE `your_table_name` AS a JOIN `your_another_table_name` AS b SET a.column = b.another_column WHERE a.id = b.a_id...;
查
普通查询
SELECT `column_name_one`, `column_name_two` FROM `table_name`;
关联查询
SELECT * FROM `your_table_name` AS a JOIN `your_anther_table_name` AS b WHERE a.column_name = b.column_name...;
合计函数条件查询:WHERE 关键字无法与合计函数一起使用
SELECT aggregate_function(column_name) FROM your_table_name GROUP BY column_name HAVING aggregate_function(column_name)...;
同一个实例下跨库查询
SELECT * FROM database_name.your_table_name AS a JOIN anther_database_name.your_anther_table_name AS b WHERE a.column_name = b.column_name...;
复制一张表结构
CREATE `your_table_name` LIKE `destination_table_name`;
完全复制一张表:表结构+全部数据
CREATE `your_table_name` LIKE `destination_table_name`; INSERT INTO `your_table_name` SELECT * FROM `destination_table_name`;
附录:mysql常用命令
登陆: mysql -h host -u username -p
列出数据库:SHOW DATABESES;
列出表:SHOW TABLES;
表结构:DESC table_name;
使用一个数据库:USE database_name;
导入:source 'file';
导出:mysqldump -h 127.0.0.1 -u root -p "database_name"
"table_name" --where="condition" >
file_name.sql;