mysql> create table TABLE_NAME ( [...], UNIQUE [INDEX_NAME] (Column(length)); 创建唯一键约束 1 mysql> alter TABLE_NAME add unique key [INDEX_NAME] on (Column(length)); 创建主键约束 1 mysql> create table TABLE_NAME(id INT NOT NULL AUTO_INCREMENT, Name VARCHAR(16) NOT NULL,PRIMARY...
方式2:insert into t1(name,id) values();# 1.not null非空# 2.default默认值# 3.unique唯一值# 4.primary key主键# 5.auto_increment自增 今日学习内容 自增特性 create table t1(idintprimary key auto_increment,# 创建表 t1 id int 主键 自动递增name varchar(32) ); insert into t1(name) value...
mysql> create table biao ( //创建一个表叫‘biao’ -> id int(4) not null primary key auto_increment, //第一个为id,类型为int,长度为4,不为空,定义其为主键,设置为自动增长 -> name varchar(10) not null, //第二个为name,类型为varchar,长度为10,不为空 -> address varchar(50) default '...
SELECT top10* FROM A SELECT * FROM A LIMIT0,10取前10行数据 CREATE TABLE #G1DaySum CREATE TEMPORARY TABLE `G1DaySum` 创建临时表 CREATE PROCEDURE AA(a INT, b INT output) CREATE PROCEDURE AA(IN a INT, OUT b INT) 存储过程参数格式 IF() BEGIN END IF() THEN END IF if用法 WHILE() ...
CREATE TABLE `TEST_TB_GRADE` ( `ID` int(10) NOT NULL AUTO_INCREMENT, `USER_NAME` varchar(20) DEFAULT NULL, `COURSE` varchar(20) DEFAULT NULL, `SCORE` float DEFAULT '0', PRIMARY KEY (`ID`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8; insert into TEST_TB_GRADE(USER_NAME...
MYI: my index 索引文件 InnoDB 存储表文件的作用: .ibd:存放数据库表数据和索引数据库:数据库也是以文件形式存储在磁盘上 Data文件中二、innodb的事物处理如果MySQL...MyISAM不支持三、建表的注意事项表的字段之间要使用逗号隔开 最后一个字段不要存在逗号数据表名不要和字段名重名 auto_increment 属性 必须依赖于...
SQL CREATE DATABASE SQL USE DATABASE SQL ALTER DATABASE SQL DROP DATABASE SQL DATA TYPES SQL COMMAND Groups SQL CREATE TABLE SQL ALTER TABLE SQL Integrity Constrain SQL AUTO INCREMENT SQL JOINS SQL RENAME SQL VIEWS SQL Subquery SQL Indexes SQL GRANT, REVOKE Oracle Functions SQL SELECT INTO SQL...
CREATEORALTERFUNCTIONdbo.ConvertRowVersionToDateTime(@DBTSBINARY(8))RETURNSSMALLDATETIMEASBEGINDECLARE@RetValSMALLDATETIME;SELECTTOP1@RetVal=WhenWasItFROMdbo.RowVersionTimeEstimatesWHERERV>=@DBTS;--If we have yet to record a value this big, that indicates the value is extremely new.IF@@ROWCOUNT=0SE...
Howt to Auto increment Alphanumeric ID Eg : IT001, IT002 in MSSQLAll replies (4)Tuesday, October 28, 2014 10:38 AM ✅AnsweredDirectly it's not possible. You can add a numeric column with IDENTITY (or a sequence) and add a calculated column to get the desired alphanumeric value....
SELECT SYSTEM_USER AS 'User' , HAS_PERMS_BY_NAME ('master', 'DATABASE', 'CREATE DATABASE') AS 'Permission Status'; GO Results: If a “1” is returned in the “Permission Status” column, congratulations, you have permission to create databases on your SQL Server instance. If a “0...