CREATE TABLE [IF NOT EXISTS] table_name( column_definition1, column_definition2, …….., table_constraints ); 也可简写为: CREATE TABLE table_name (column_name column_type); 上述语法的参数说明如下: 以下例子中我们将在 RUNOON 数据库中创建数据...
mysql> create table uu(id int unsigned not null primary key auto_increment, user_name varchar(15) not null)auto_increment=100; Query OK, 0 rows affected (0.01 sec) mysql> === mysql>insert into uu(id,user_name) values(1, 'jojo'); Query OK, 1 row affected (0.00 sec) mysql>insert...
This section discusses the relationship of partitioning keys with primary keys and unique keys. The rule governing this relationship can be expressed as follows: All columns used in the partitioning expression for a partitioned table must be part of every unique key that the table may have. In ...
For example - CREATE TABLE table1 ( column1 INT(11), column2 INT(11), PRIMARY KEY (column1) ); ALTER TABLE table1 DROP INDEX `PRIMARY`, ADD PRIMARY KEY (column1, column2); Devart Company, MySQL management tools http://www.devart.com/dbforge/mysql/...
倒数第四段，CREATE TABLE creates a table with the given name. You must have theCREATE privilege for the table.告诉你，你必须拥有 表的 CREATE 权限，才可以创建表。除了以上倒数四段，其他的段，都是语法语句结构。好吧，我们必须看明白语法结构才可以。以下是分离出来的第1~3段信息。蓝色文字标出的是...
create table customers(id int auto_increment primary key not null, name varchar(15)); insert into customers(name) values("name1"),("name2"); select id from customers; 1. 2. 3. 4. 5. 以上sql语句先创建了customers表,然后插入两条记录,在插入时仅仅设定了name字段的值。最后查询表中id字段,...
ALTER TABLE table_name ADD PRIMARY KEY(primary_key_column); 以下示例将id列添加到主键。 首先,创建 t1表而不定义主键。 CREATE TABLE t1( id INT, title VARCHAR(255) NOT NULL ); 其次,将id 列作为t1表的主键。 ALTER TABLE t1 ADD PRIMARY KEY(id); ...
---约束演示---create tableyuser(id int primary key auto_increment comment'主键',namevarchar(10)notnullunique comment'姓名',age intcheck(age>0&&age<=120)comment'年龄',statuschar(1)default'1'comment'状态',genderchar(1)comment'性别')comment'用户表';--插入数据 insert intoyuser(name,age,sta...
localhost:ytt> show create table t1\G *** 1. row *** : t1 Create Table: CREATE TABLE `t1` ( `id` int NOT NULL, `r1` date DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci 1 row in set (0.00 sec) localhost:ytt> show ...
CREATE TABLE innodb_lock_monitor (a INT) ENGINE=INNODB; DROP TABLE innodb_lock_monitor; MySQL 5.6.16 版本之后,修改系统参数 innodb_status_output 后,使用show engine innodb status查看 set GLOBAL innodb_status_output=ON; set GLOBAL innodb_status_output_locks=ON; ...