CREATE TABLE student ( id INT, sn INT comment '学号', name VARCHAR(20) comment '姓名', qq_mail VARCHAR(20) comment 'QQ邮箱' ); 1. 2. 3. 4. 5. 6. 7. 8. 单行数据 + 全列插入 -- 插入两条记录,value_list 数量必须和定义表的列的数量及顺序一致 INSERT INTO student VALUES (100, ...
1、modify、change都可以修改列的属性;一同的是modify只能修改表的数据类型、change比它要牛逼一点它可以在修改数据类型的同时也修改列名。 2、modify 的语法:alter table table_name modify new_colum_defnition。 如:alter table user modify id bigint; 3、change的语法:alter table table_name change old_colum...
which is a bit of a misleading term). This is done in order to allow users to see a consistent view of the system without expensive and performance-constraining locking which would limit concurrency. (This
1833 - Cannot change column ‘XXX’: used in a foreign key constraint ‘XXX’ of table ‘XXX.XXX’ 错误原因: 由于外键关联问题,修改表结构时出现问题。 解决方案: ①把表中的外键全部去除。 ②删除该表,重新建表。 扫码添加技术【解决问题】 专注企业网站建设、网站安全16年。 承接:企业网站建设、网站...
1846 (0A000): ALGORITHM=INPLACE is not supported.问题现象在RDS MySQL实例中,使用INPLACE方式扩展VARCHAR字段长度时,提示如下错误:ERROR 1846 (0A000):ALGORITHM=INPLACE is not suppor...
The parameter innodb_large_prefix was introduced in MySQL 5.5, so that users could avoid accidentally creating tables that would be incompatible with the InnoDB Plugin in MySQL 5.1. Now that MySQL 5.1 is not supported any more, it makes no sense to use any other value than innodb_large_prefi...
Disable MySQL's constraint checks, otherwise, it won't allow modifications on the tables; 1SETforeign_key_checks=0; Alter the collation of a table with the below query; 1ALTERTABLE<table-name>CONVERTTOCHARACTERSETutf8COLLATEutf8_bin;
change buffer是内存中的一块区域,它保存在Innodb的buffer pool中,它在磁盘上也有对应的持久化空间,在系统表空间ibdata中。MySQL中的change buffer信息如下,默认值是25,代表它的大小最大只能占用到innodb buffer pool的25%大小,如下: 代码语言:javascript
on the replica. A warning (ER_WARN_OPEN_TEMP_TABLES_MUST_BE_ZERO) is issued whenever this occurs. You can avoid this in such cases by making sure that the value of theReplica_open_temp_tablessystem status variable is equal to 0 prior to executing such aCHANGE REPLICATION SOURCE TO...
errorinMySQL that makes the server to die when trying to rename a tablewithFKs.See https://bugs.mysql.com/bug.php?id=96145Since pt-online-schema change needs to rename the old<->newtablesasthe final step,and the requested table has FKs,it cannot be executed under the current MySQL versi...