userName1 VARCHAR(70) UNIQUE NOT NULL, FOREIGN KEY(userName1) REFERENCES User(userName), Product VARCHAR(70) NOT NULL, INDEX(orderID, userName1)) How does a query, that wants to insert data into the "Order" table, has to look like?
#修改默认值:ALTER TABLE testalter_tbl ALTER i SET DEFAULT 1000;#删除默认值:ALTER TABLE testalter_tbl ALTER i DROP DEFAULT; #更改表名rename table 原表名 to 新表名; 增删改表的字段 三、表内容操作 1、增 语法:insert into 表 (列名,列名...) values (值,值,值...) #插入单条数据insert in...
ERROR1075(42000): Incorrecttabledefinition; there can beonlyone autocolumnandit must be definedasakeycreatetabletest(numintprimarykeyauto_increment);--思考,如何删除主键?altertabletest modify idint;--auto_increment没了,但这样写主键依然存在,所以还要加上下面这句altertabletestdropprimarykey;--仅仅用这...
Insert some rows into the child table using the statement shown here: mysql> INSERT INTO child (id,parent_id) VALUES ROW(1,1), ROW(2,1), ROW(3,1); Verify that the data was inserted, like this: mysql> TABLE child; +---+---+ | id | parent_id | +---+---+ | 1 | ...
mysql> SET FOREIGN_KEY_CHECKS=0;如果存在外键,要关闭外键约束 Query OK, 0 rows affected (0.00 sec) mysql> load data infile '/tmp/ec_school.sql' into table ec_school.action_group;/root目录下可能会出现cannot get stat的报错 Query OK, 28 rows affected (0.04 sec) ...
show table status from 数据库名 like 'runob%'\G; // 加上\G,查询结果按列打印 1. 2. 3. 14.创建数据库: create database 数据库名; 1. 15.删除数据库: drop database 数据库名; 1. 16.MySQL中的数据类型 MySQL支持多种类型,大致可以分为三类:数值、日期/时间和字符串(字符)类型。
在事务内创建TEMPORARY TABLE或DROP TEMPORARY TABLE语句 更新事务和非事务表的事务或语句。 enforce_gtid_consistency仅在语句进行二进制日志记录时生效。如果在服务器上禁用了二进制日志记录,或者由于过滤器删除了语句而未将语句写入二进制日志,则不会对未记录的语句检查或强制执行GTID一致性。
CREATE TABLE T1(A INT PRIMARY KEY, B INT, C CHAR(1)) ENGINE=InnoDB; 代码语言:javascript 代码运行次数:0 运行 AI代码解释 INSERTINTOT1VALUES (1,2,'a'), (2,3,'b'), (3,2,'c'), (4,3,'d'), (5,2,'e');COMMIT;ALTERTABLET1ADDINDEX(B),ADDUNIQUEINDEX(C); ...
MySQL supports foreign keys, which permit cross-referencing related data across tables, and foreign key constraints, which help keep the related data consistent. A foreign key relationship involves a parent table that holds the initial column values, and a child table with column values that referen...
mysql>insert into t3_bak_1124 select*from t3_bak limit3;QueryOK,3rowsaffected(0.01sec)Records:3Duplicates:0Warnings:0 1. 2. 3. 查看锁等待信息 其中: 给t3_bak 表中扫描的每行数据的主键索引加 S 型 next-key lock。 分析 执行流程