department_idINT);-- 插入示例数据INSERTINTOdepartments (department_name)VALUES('HR'), ('Engineering');INSERTINTOemployees (first_name, last_name, department_id)VALUES('John','Doe',1), ('Jane','Smith',2), ('Jim','Brown',NULL); 要删除employees表中department_id为NULL的记录,可以使用以下语...
building_no INT NOT NULL, FOREIGN KEY (building_no) REFERENCES buildings (building_no) ON DELETE CASCADE )ENGINE=InnoDB DEFAULT CHARSET=utf8; 注意:在外键约束定义的末尾添加ON DELETE CASCADE子句。 第三步, 将一些数据插入到buildings表,如下插入语句: INSERT INTO buildings(building_name,address) VALUES...
SQL CREATETABLEdbo.Table1 (ColAintNOTNULL, ColBdecimal(10,3)NOTNULL); GOCREATETABLEdbo.Table2 (ColAintPRIMARYKEYNOTNULL, ColBdecimal(10,3)NOTNULL); GOINSERTINTOdbo.Table1VALUES(1,10.0), (1,20.0);INSERTINTOdbo.Table2VALUES(1,0.0); GODELETEdbo.Table2FROMdbo.Table2INNERJOINdbo.Table1ON(...
AI代码解释 mysql>create tableundo_demo(->id int notnull,->key1varchar(100),->colvarchar(100),->primarykey(id),->keyidx_key1(key1)->);QueryOK,0rowsaffected(0.05sec) 表中id主键,key1是二级索引,col是普通列。我们前面说过每个表都有一个唯一的table id,在information_Shcema中的innodb_sys_ta...
INSERT INTO course VALUES('03' , '英语' , '03'); --3条记录 SELECT count(1) FROM cours...
name}, </if> <if test="item.age != null"> age=#{item.age} </if> </set> WHERE id=#{item.id}; </foreach> </update> 控制台sql语句: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 Preparing: UPDATE mutest.student SET name=?, age=? WHERE id=?; UPDATE mutest.student SET...
mysql tables in use 1, locked 1 7 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 4 MySQL thread id 300, OS thread handle 140425969882880, query id 5479930 172.18.70.114 root update insert into session_endpoint (...) values (...) ...
对于sql 节点的信息比较简单我们直接看源码: /*** 这个方法没做什么具体的操作,最后就是把sql节点的内容 放进了 sqlFragments 里 * private final Map<String, XNode> sqlFragments; *@paramlist*/privatevoidsqlElement(List<XNode>list) {//databaseIdif(configuration.getDatabaseId() !=null) { ...
2)查看正在执行的SQL insert into account values(null,'Jay',100) 1. 3)正在等待锁释放(WAITING FOR THIS LOCK TO BE GRANTED),插入意向排他锁(lock_mode X locks gap before rec insert intention waiting),普通索引(idx_name),物理记录(PHYSICAL RECORD),间隙区间(未知,Wei); ...
`name` varchar(255) DEFAULT NULL, `state` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=18 DEFAULT CHARSET=utf8; 1. 2. 3. 4. 5. 6. AI检测代码解析 begin; SELECT * from city where id = "1" lock in share mode;(不提交,commit) ...