说一下Mysql的select into语法复制表
在MySQL里,`SELECT INTO` 语法在标准SQL中用于将查询结果插入到新表,但MySQL并不支持这种标准的 `SELECT INTO` 语法。不过可以使用 `CREATE TABLE ... SELECT` 语句来实现复制表的功能。 以下是使用 `CREATE TABLE ... SELECT` 复制表的示例代码: ```sql -- 创建一个新表,表名为new_table,结构和数据来自于old_table CREATE TABLE new_table SELECT * FROM old_table; ``` 代码解释: - `CREATE TABLE new_table`:创建一个名为 `new_table` 的新表。 - `SELECT * FROM old_table`:从 `old_table` 中选取所有的列和行。当执行这个语句时,`new_table` 会拥有和 `old_table` 相同的列结构,并且会复制 `old_table` 中的所有数据。 如果只想复制表结构,不复制数据,可以使用以下代码: ```sql -- 创建一个新表,表名为new_table,只复制old_table的结构 CREATE TABLE new_table SELECT * FROM old_table WHERE 1=0; ``` 代码解释: - `WHERE 1=0` 这个条件永远为假,所以不会有任何行被选中,这样 `new_table` 只会有和 `old_table` 相同的列结构,而没有数据。 我在以往的开发过程中,碰到过以下几点需要格外小心处理的地方: 1. 新表的索引和约束不会自动从原表复制过来,需要手动添加。 2. 如果原表有自增列,复制后自增属性可能需要重新设置。 3. 要确保有足够的权限来创建新表,否则会导致创建失败。 [2026-01-19 09:23:32 | AI写代码神器 | 382点数解答]
- [GPT] 帮我优化一下这个sql, 得到的结果是一样的 select to_char(sysdate, 'yyyymmdd') from dual union select to_char(sysdate-1, 'yyyymmdd') from dual union select to_char(sysdate-2, 'yyyymmdd') from dual union select to_char(sysdate-3, 'yyyymmdd') from dual union select to_char(sysdate-5, 'yyyymmdd') from dual(357点数解答 | 2024-08-14 20:08:27)394
- [GPT] 我想得到最近30天内的日期, 比如这样的sql, 但太冗余了, 有没有简化的办法, oracle库里执行: select to_char(sysdate, 'yyyymmdd') from dual union select to_char(sysdate-1, 'yyyymmdd') from dual union select to_char(sysdate-2, 'yyyymmdd') from dual union select to_char(sysdate-3, 'yyyymmdd') from dual union select to_char(sysdate-5, 'yyyymmdd') from dual(320点数解答 | 2024-08-14 20:11:26)248
- [字节豆包] 用c语言实现一个64位地址— select [0] = (6^11^16^…^51) — select [1] = (7^12^17^…^47) — select [2] = (8^13^18^…^48) — select [3] = (9^14^19^…^49) — select [4] = (10^15^20^…^50)(312点数解答 | 2024-11-19 15:34:19)213
- [讯飞星火] master.driver = com.mysql.jdbc.driver master.url = jdbc:mysql://10.9.1.210:3306/drdisplayv3_dev?usessl=false&useunicode=true&characterencoding=utf-8&zerodatetimebehavior=converttonull&transformedbitisboolean=true master.username = root master.password = root 副表配置 slave.driver = com.mysql.jdbc.driver slave.url = jdbc:mysql://localhost:3306/drdisplay?usessl=false&useunicode=true&characterencoding=utf-8&zerodatetimebehavior=converttonull&transformedbitisboolean=true slave.username = root slave.pas(92点数解答 | 2024-06-26 15:47:44)327
- [讯飞星火] master.driver = com.mysql.jdbc.driver master.url = jdbc:mysql://10.9.1.210:3306/drdisplayv3_dev?usessl=false&useunicode=true&characterencoding=utf-8&zerodatetimebehavior=converttonull&transformedbitisboolean=true master.username = root master.password = root 副表配置 slave.driver = com.mysql.jdbc.driver slave.url = jdbc:mysql://localhost:3306/drdisplay?usessl=false&useunicode=true&characterencoding=utf-8&zerodatetimebehavior=converttonull&transformedbitisboolean=true slave.username = root slave.pass(210点数解答 | 2024-06-26 15:49:53)309
- [字节豆包] .假设自动售货机出售4种商品,薯片(crisps)、爆米花(popcorn)、巧克力(chocolate)和可乐(cola),售价分别是每份3.0、2.5、4.0和3.5元。在屏幕上显示以下菜单,用户可以连续查询商品的价格,当查询次数超过5次时,自动退出查询;不到5次时,用户可以选择退出。当用户输入编号1~4,显示相应商品的价格;输入0,退出查询;输入其他编号,显示价格为0。 [1] Select crisps [2] Select popcorn [3] Select chocolate [4] Select cola [0] Exit (403点数解答 | 2025-11-24 00:18:28)28
- [讯飞星火] 1、 运行下面的sql脚本 drop database if exists mybatis_test_db; create database mybatis_test_db; use mybatis_test_db; create table users ( uid int primary key auto_increment comment 'id', uname varchar(30) not null comment '姓名', upwd varchar(30) comment '密码', uage int comment '年龄', usex char(2) comment '性别', ubirthday date comment '生日' ) comment '用户表'; insert into users(uname,upwd,uage,usex,ubirthday) values('allen','123',23,'男','2008-07-11'); insert into users(uname,upwd,uage,usex,ubirthday) va(493点数解答 | 2024-11-18 08:04:14)305
- select c.table_name, c.constraint_name, c.constraint_type, c.status, c.r_owner, c.r_constraint_name, (select rc.table_name from all_constraints rc where rc.owner = c.r_owner and rc.constraint_name = c.r_constraint_name) as r_table_name, c.delete_rule, ( select listagg(column_name || ':' || position,',') within group (order by "position") from all_cons_columns col where col.owner =:1 and col.table_name = :2 and col.constraint_n(25点数解答 | 2024-01-17 17:17:40)328
- [阿里通义] if (@code2 like 'item_ch_' + @itemcodeprefix + '_a_rare' and @optlevel >= 1 - @ck and @cl1 = 24670 and @cl2 = 24669 and @clsl1 > 1 and @clsl2 > 1) begin select @charname = charname16 from _char where charid = @charid; update _inventory set itemid=0 where charid=@charid and slot=13 update sro_vt_shard.._items set data=data-1 where id64 in (select itemid from sro_vt_shard.._inventory where slot=14and charid=@charid) update sro_vt_shard.._items set data=data-1 where id64 in (select itemid from sro_(969点数解答 | 2024-10-22 11:26:02)328
- [阿里通义] select distinct t.id_card,t.`start`,t.`end` from ((select distinct(person_name), id_card , date_format( curdate(), "%y-%m-%d 00:00:00" ) start , date_format( curdate(), "%y-%m-%d 23:59:59" ) end, '1' ordertype, '-1' pass from t_contractor_people where person_name in ( select distinct ( b.executor ) from t_task_work_order a left join t_task_work_person b on a.sheet_id = b.hot_work_id where a.valid = '1' and a.work_start_time > date_format( curdate(), "%y-%m-%d 00:00:00(342点数解答 | 2024-12-05 12:31:57)224
- [GPT] select distinct t.id_card,t.`start`,t.`end` from ((select distinct(person_name), id_card , date_format( curdate(), "%y-%m-%d 00:00:00" ) start , date_format( curdate(), "%y-%m-%d 23:59:59" ) end, '1' ordertype, '-1' pass from t_contractor_people where person_name in ( select distinct ( b.executor ) from t_task_work_order a left join t_task_work_person b on a.sheet_id = b.hot_work_id where a.valid = '1' and a.work_start_time > date_format( curdate(), "%y-%m-%d 00:00:00(24点数解答 | 2024-12-05 12:32:54)248
- [阿里通义] insert into pacsdb.diagnose_report_del select *,now() from pacsdb..diagnose_report t where t.report_no = #{reportno} 把这条sql改写成mybatis-plus代码(868点数解答 | 2024-10-17 14:05:35)112