insert into from和insert into select有什么区别？
select into from 和 insert into select都是用来复制表，两者的主要区别为： select into from 要求目标表不存在，因为在插入时会自动创建。insert into select from 要求目标表存在。备份表数据： create table emp as select * from scott.emp还原表数据：insert into emp select * from scott.emp复制表结构及其数据：create table table_name_new as select * from table_name_old只复制表结构：create table table_name_new as select * from table_name_old where 1=2;或者：create table table_name_new like table_name_old只复制表数据：如果两个表结构一样：insert into table_name_new select * from table_name_old如果两个表结构不一样：insert into table_name_new(column1,column2...) select column1,column2...from table_name_old pasting
什么是select into from和insert into select？
select into from 和 insert into select都是用来复制表，两者的主要区别为： select into from 要求目标表不存在，因为在插入时会自动创建。insert into select from 要求目标表存在。备份表数据： create table emp as select * from scott.emp还原表数据：insert into emp select * from scott.emp复制表结构及其数据：create table table_name_new as select * from table_name_old只复制表结构：create table table_name_new as select * from table_name_old where 1=2;或者：create table table_name_new like table_name_old只复制表数据：如果两个表结构一样：insert into table_name_new select * from table_name_old如果两个表结构不一样：insert into table_name_new(column1,column2...) select column1,column2...from table_name_old pasting
如何使用select into 进行备份mysql数据库
使用SELECT INTO进行备份与MYSQLDUMP很相似，同样是把数据库备份到一个指定的文件中。其结果文件只能被建立在MySQL服务器上，而不是任何其他主机。SELECT INTO语句的语法格式如下：
Select … into outfile 'path_and_filename' ;
示例：
使用SELECT INTO语句查询数据库“mr_mysql”中的“mr_gly”表，把该表备份到“D:\\gly.txt”目录下，文件的名称是“gly.txt”。
mysql> use mr_mysql
Database changed
mysql> select * from mr_gly into outfile "D:\\gly.txt";
Query OK, 5 rows affected (0.00 sec)
下面的这些参数是SELECT INTO语句的非默认参数。
[fields
[terminated by '\t' ] //设置输出文件以什么作为分界标识
[enclosed by '' ] //指定的字符包围了所有的域
[[optionally] enclosed by '' ] //指定只有字符域被包括
[escaped by '\\'] ]
[lines terminated by '\n' ] //设置长行的中断被什么字符代替
下面是应用了SELECT INTO语句非默认参数的几个示例。
示例：
在每个域之间，默认的制表符被字符“|”代替。
mysql> use tpsc
Database changed
mysql> select * from jtsr into outfile "D:\\user1.txt" fields terminated by '|' ;
Query OK, 5 rows affected (0.00 sec)
示例：
Enclosed关键字用指定的字符“双引号”包围了所有的域。
mysql> select * from jtsr into outfile "D:\\user2.txt" fields terminated by '|' enclosed by '"';
Query OK, 5 rows affected (0.02 sec)
示例：
Optionally关键字的使用，导致了只有字符域被双引号包括。
mysql> select * from jtsr into outfile "D:\\user3.txt" fields terminated by '|' optionally enclosed by '"' ;
Query OK, 5 rows affected (0.02 sec)
示例：
lines terminated的使用，使每行之间的中断被字符“\n”
代替。
mysql> select * from jtsr into outfile "D:\\user4.txt" fields terminated by '|' lines terminated by '\n' ;
Query OK, 5 rows affected (0.02 sec)
示例：
综合使用这些参数。
mysql> select * from jtsr into outfile "D:\\user5.txt" fields terminated by '|' optionally enclosed
by '"' lines terminated by '\n' ;
Query OK, 5 rows affected (0.02 sec)
示例：
使用SELECT语句中的条件进行备份。
mysql> select * from jtsr where id>3 into outfile "D:\\user6.txt" fields terminated by '|' optionall
y enclosed by '"' lines terminated by '\n' ;
Query OK, 2 rows affected (0.01 sec)
注意：在使用SELECT INTO语句时，为备份的文件命名时切忌不要重写已存在的文件;在编写文件输出的位置时不要忘记使用换码符“\”。