Search results
Learn how to create a table with a primary key constraint using CREATE TABLE or ALTER TABLE statements. See examples of single and multiple column primary keys in MySQL, SQL Server, Oracle and MS Access.
13 wrz 2021 · To create a Primary key in the table, we have to use a keyword; “PRIMARY KEY ( )” Query: CREATE TABLE `Employee` ( `Emp_ID` VARCHAR(20) NOT NULL ,`Name` VARCHAR(50) NOT NULL , `Age` INT NOT NULL ,`Phone_No` VARCHAR(10) NOT NULL ,`Address` VARCHAR(100) NOT NULL , PRIMARY KEY (`Emp_ID`));
18 kwi 2024 · Creating a new table with a primary key requires CREATE TABLE permission in the database and ALTER permission on the schema in which the table is being created. Creating a primary key in an existing table requires ALTER permission on the table.
To create a new table with a column defined as the primary key, you can use the keyword PRIMARY KEY at the end of the definition of that column. In our example, we create the table product using a CREATE TABLE clause, with the names of the columns and their respective data types in parentheses.
Learn what a primary key is and how to use the PRIMARY KEY constraint to add a primary key to a table. See examples of creating tables with one or more columns as primary keys and how to alter or drop them.
This tutorial shows you how to use SQLite PRIMARY KEY constraint to define the primary key for a table.
14 lis 2024 · Define a primary key table constraint for the table films: CREATE TABLE films ( code char(5), title varchar(40), did integer, date_prod date, kind varchar(10), len interval hour to minute, CONSTRAINT code_title PRIMARY KEY(code,title) );
