mysql create table unique
A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an ... ,SQL UNIQUE Constraint on ALTER TABLE. To create a UNIQUE constraint on the "ID" column when the table is already created, use the following SQL: MySQL ... , UNIQUE 用來保證欄位在資料表中的唯一性，約束資料表中的欄位不能有重複的資料。 ... CREATE TABLE customer ( C_Id INT NOT NULL UNIQUE, Name ... MySQL. ALTER TABLE customer DROP INDEX u_Customer_Id;.,To define a UNIQUE constraint for a column when you create a table, you use this syntax: CREATE TABLE table_name( ..., column_name data_type UNIQUE, ... ); In this syntax, you include the UNIQUE keyword in the definition of the column that you want to enf,CREATE TABLE table_name( ... UNIQUE KEY(index_column_,index_column_2,...) ); In this statement, you can also use the UNIQUE ... ,The syntax for creating a unique constraint using an ALTER TABLE statement in MySQL is: ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column1, column2, ... column_n); ,CREATE TABLE Persons ( Id_P int NOT NULL UNIQUE , LastName varchar(255) NOT NULL, FirstName ... MySQL / SQL Server / Oracle / MS Access: CREATE ... , CREATE TABLE `phpcolor_ad` ( `id` mediumint(8) NOT NULL AUTO_INCREMENT, `name` varchar(30) NOT NULL, `type` mediumint(1) NOT ...,CREATE TABLE t1 ( col1 INT NOT NULL, col2 DATE NOT NULL, col3 INT NOT NULL, col4 INT NOT NULL, UNIQUE KEY (col1, col2) ) PARTITION BY ... , Primary Key比較沒有爭議，它一定是非null且unique，並且一個table只能 ... http://dreamlandit.wordpress.com/2013/02/20/creating-a-mysql-index/
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 mysql create table unique 相關參考資料
13.1.20 CREATE TABLE Statement - MySQL :: Developer Zone
A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an ... https://dev.mysql.com SQL UNIQUE Constraint - W3Schools
SQL UNIQUE Constraint on ALTER TABLE. To create a UNIQUE constraint on the "ID" column when the table is already created, use the following SQL: MySQL ... https://www.w3schools.com SQL UNIQUE Constraint 限制- SQL 語法教學Tutorial
UNIQUE 用來保證欄位在資料表中的唯一性，約束資料表中的欄位不能有重複的資料。 ... CREATE TABLE customer ( C_Id INT NOT NULL UNIQUE, Name ... MySQL. ALTER TABLE customer DROP INDEX u_Customer_Id;. https://www.fooish.com MySQL UNIQUE Constraint - MySQL Tutorial
To define a UNIQUE constraint for a column when you create a table, you use this syntax: CREATE TABLE table_name( ..., column_name data_type UNIQUE, ... ); In this syntax, you include the UNIQUE keywo... https://www.mysqltutorial.org Using MySQL UNIQUE Index To Prevent Duplicates
CREATE TABLE table_name( ... UNIQUE KEY(index_column_,index_column_2,...) ); In this statement, you can also use the UNIQUE ... https://www.mysqltutorial.org MySQL: Unique Constraints - TechOnTheNet
The syntax for creating a unique constraint using an ALTER TABLE statement in MySQL is: ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column1, column2, ... column_n); https://www.techonthenet.com SQL UNIQUE 约束 - w3school 在线教程
CREATE TABLE Persons ( Id_P int NOT NULL UNIQUE , LastName varchar(255) NOT NULL, FirstName ... MySQL / SQL Server / Oracle / MS Access: CREATE ... https://www.w3school.com.cn Mysql中key 、primary key 、unique key 與index區別- IT閱讀
CREATE TABLE `phpcolor_ad` ( `id` mediumint(8) NOT NULL AUTO_INCREMENT, `name` varchar(30) NOT NULL, `type` mediumint(1) NOT ... https://www.itread01.com MySQL 8.0 Reference Manual :: 23.6.1 Partitioning ... - MySQL
CREATE TABLE t1 ( col1 INT NOT NULL, col2 DATE NOT NULL, col3 INT NOT NULL, col4 INT NOT NULL, UNIQUE KEY (col1, col2) ) PARTITION BY ... https://dev.mysql.com Primary、Unique、Index各代表什麼意義? | MySQL Taiwan
Primary Key比較沒有爭議，它一定是非null且unique，並且一個table只能 ... http://dreamlandit.wordpress.com/2013/02/20/creating-a-mysql-index/ https://www.mysql.tw |