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本文结合具体的实例讲解mysql基础常用语法
CREATE DATABASE
CREATE DATABASE db_name
CREATE DATABASE用给定的名字创建一个数据库，创建数据库mysqllearn。
create database mysqllearn;
CREATE TABLE
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [select_statement] create_definition: col_name type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [PRIMARY KEY] [reference_definition] or PRIMARY KEY (index_col_name,...) or KEY [index_name] (index_col_name,...) or INDEX [index_name] (index_col_name,...) or UNIQUE [INDEX] [index_name] (index_col_name,...) or [CONSTRAINT symbol] FOREIGN KEY index_name (index_col_name,...) [reference_definition] or CHECK (expr)
CREATE TABLE在当前数据库中用给出的名字创建一个数据库表，创建数据库表t_video。
DROP TABLE IF EXISTS `t_video`; CREATE TABLE `t_video` ( `id` int(11) NOT NULL AUTO_INCREMENT, `code_number` varchar(20) NOT NULL, `name` varchar(100) DEFAULT NULL, `director` varchar(50) DEFAULT NULL, `starring` varchar(100) DEFAULT NULL, `release_time` date DEFAULT NULL, `production_area` varchar(50) DEFAULT NULL, `showtimes` int(11) DEFAULT ‘0‘, `hits` int(11) DEFAULT ‘0‘, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
ALTER TABLE
ALTER [IGNORE] TABLE tbl_name alter_spec [, alter_spec ...] alter_specification: ADD [COLUMN] create_definition [FIRST | AFTER column_name ] or ADD INDEX [index_name] (index_col_name,...) or ADD PRIMARY KEY (index_col_name,...) or ADD UNIQUE [index_name] (index_col_name,...) or ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT} or CHANGE [COLUMN] old_col_name create_definition or MODIFY [COLUMN] create_definition or DROP [COLUMN] col_name or DROP PRIMARY KEY or DROP INDEX index_name or RENAME [AS] new_tbl_name or table_options
ALTER TABLE允许你修改一个现有表的结构。例如，你可以增加或删除列、创造或消去索引、改变现有列的类型、或重新命名列或表本身。你也能改变表的注释和表的类型。
现在我们尝试去修改刚刚定义的表t_video中showtimes和hits字段的数据格式，修改前表结构可用describe tb_name来查看：
讲主演starring字段长度修改为200，修改语句如下：
alter table t_video modify starring varchar(200);
INSERT
INSERT [LOW_PRIORITY | DELAYED] [IGNORE] [INTO] tbl_name [(col_name,...)] VALUES (expression,...),(...),... 或 INSERT [LOW_PRIORITY | DELAYED] [IGNORE] [INTO] tbl_name [(col_name,...)] SELECT ... 或 INSERT [LOW_PRIORITY | DELAYED] [IGNORE] [INTO] tbl_name SET col_name=expression, col_name=expression, ...
INSERT把新行插入到一个存在的表中，INSERT ... VALUES形式的语句基于明确指定的值插入行，INSERT ... SELECT形式插入从其他表选择的行。
插入部分实例数据如下：
INSERT INTO `t_video` VALUES (‘1‘, ‘F_C_001‘, ‘心花怒放‘, ‘宁浩‘, ‘黄渤,徐峥,袁泉,周冬雨,陶慧‘, ‘2014-09-30‘, ‘中国‘, ‘0‘, ‘0‘);
INSERT INTO `t_video` VALUES (‘2‘, "F_C_002","黄金时代","许鞍华","汤唯 冯绍峰 王志文 朱亚文 黄轩","2014-10-01","中国","100","102400");
INSERT INTO `t_video` VALUES (‘3‘, "F_C_003","食人虫","严嘉","夏梓桐 张梓琳 王传君 丁春诚 ","2014-10-10","中国","121","102100");
INSERT INTO `t_video` VALUES (‘4‘, "F_C_004","一生一世","邹佡","谢霆锋 高圆圆 杜海涛 洛诗 林雪 车晓","2014-09-05","中国","100","102421");
INSERT INTO `t_video` VALUES (‘5‘, "F_C_005","亲爱的","陈可辛","赵薇 黄渤 佟大为 郝蕾 张译 张雨绮","2014-09-25","中国","100","102422");
INSERT INTO `t_video` VALUES (‘6‘, "F_C_006","闺蜜","黄真真","陈意涵 薛凯琪 杨子姗 余文乐 钟汉良 吴建豪","2014-07-31","中国","100","102434");
DELETE
DELETE [LOW_PRIORITY] FROM tbl_name [WHERE where_definition] [LIMIT rows]
DELETE从tbl_name表中删除满足由where_definition给出的条件的行，并且返回删除记录的个数。如果你发出一个没有WHERE子句的DELETE，则所有行都被删除。
删除id=6的记录示意如下：
SELECT
SELECT [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [HIGH_PRIORITY] [DISTINCT | DISTINCTROW | ALL] select_expression,... [INTO {OUTFILE | DUMPFILE} ‘file_name‘ export_options] [FROM table_references [WHERE where_definition] [GROUP BY col_name,...] [HAVING where_definition] [ORDER BY {unsigned_integer | col_name | formula} [ASC | DESC] ,...] [LIMIT [offset,] rows] [PROCEDURE procedure_name] ]
SELECT被用来检索从一个或多个表中精选的行。select_expression指出你想要检索的列。SELECT也可以用来检索不引用任何表的计算行。
LOAD DATA INFILE
LOAD DATA [LOW_PRIORITY] [LOCAL] INFILE ‘file_name.txt‘ [REPLACE | IGNORE] INTO TABLE tbl_name [FIELDS [TERMINATED BY ‘\t‘] [OPTIONALLY] ENCLOSED BY ‘‘] [ESCAPED BY ‘\\‘ ]] [LINES TERMINATED BY ‘\n‘] [IGNORE number LINES] [(col_name,...)]
MySQL的LOAD DATA INFILE语句用于高速地从一个文本文件中读取行，并装入一个表中。文件名称必须为一个文字字符串。下面以MySQL5为例说明，说明如何使用MySQL的LOAD DATA命令实现文本数据的导入。
数据库中，最常见的写入数据方式是通过SQL INSERT来写入，另外就是通过备份文件恢复数据库，这种备份文件在MySQL中是SQL脚本，实际上执行的还是在批量INSERT语句。在实际中，常常会遇到两类问题：一类是数据导入，比如从word、excel表格或者txt文档导入数据（这些数据一般来自于非技术人员通过OFFICE工具录入的文档）；一类数据交换，比如从MySQL、Oracle、DB2数据库之间的数据交换。
接下来介绍一下mysql的数据导入和导出
将表t_video表中的数据导出到d:/data.txt目录文件中：
SELECT * FROM t_video INTO OUTFILE ‘d:/data.txt‘ FIELDS TERMINATED BY ‘,‘ lines terminated by ‘\r\n‘;
文件导出后将t_video表清空，再执行导入
LOAD DATA INFILE ‘d:/data.txt‘ into table t_video FIELDS TERMINATED BY ‘,‘ lines terminated by ‘\r\n‘;
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原文地址：http://www.cnblogs.com/molyeo/p/4339577.html
