1. SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' 2. AS statement FROM 3. WHERE table_schema = 'database_name' AND table_name LIKE 'myprefix_%'; 1. 2. 3. 然后执行该组装后的命令,比如从slowquery表中删除掉所有tmp_开头的表: 1. SELECT CONCAT( 'DROP TABLE ', GROUP...
drop table 表名; go --当表结构不存在时 --建表语法声明 create table 表名 ( --字段声明 列名int identity(1,1) not null, 列名int, primary key clustered(id asc) with(ignore_dup_key=off) on [primary], --主键索引声明 constraint 外键名 foreign key(列名) references 主表名(列名) on updat...
# tell mysql to ignore foreign keys for a little while SET FOREIGN_KEY_CHECKS = 0; # drop my old database table drop tableifexists entities; # re-create my table create table entities ( idintunsigned auto_increment notnullprimary key, project_idintunsigned notnull, name varchar(64) notn...
SET FOREIGN_KEY_CHECKS = 1; -- Re-enable foreign key checks Step #5: Execute Queries Copy and paste the output of the SELECT query (the list of DROP TABLE statements) and run it in the MySQL prompt. This will drop all the tables in the selected database. Method #2: MySQL DROP All...
alter table 表2 drop foreign key 外键名; 例如: 添加外键: alter table info add constraint fk_info_depart foreign key info(depart_id) references depart(id); 删除上面外键: alter table info drop foreign key fk_info_depart; 34.【mysql-数据表设计】 需求调研、数据表设计占工作的60%~70%。只有把...
drop table student2; 14. 禁止预读表信息 mysql> use performance_schema; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A mysql -uroot –p123456 -A # 禁止预读表信息 ...
then i added the foreign key thus; alter table staff add constraint fk_staff foreign key(student_with) references students on update cascade on delete set null; but when i try to drop the foreign key like this; alter table staff drop foreign key fk_staff; it says query ok, 2 row...
drop table if exists tb_role_acl;检查表是否存在，如果存在则删除表，估计你之前已经创建过该表，然后其中涉及到外键，这种情况首先得删除外键约束，然后才能删除表。删除约束的语法如下：alter table 表名称 drop constraint 约束名称
alter table 表名 add/change 5.删除 drop table +数据表名字; 6.给表重新命名 alter table 表名 rename to 新表名; 三.DML数据元素操作 操作方法 因为这是表中数据处理,不用额外加table,而是直接加表名就行 1.添加数据 insert to 表名(字段1,字段2) values (值1,值2); ...