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MariaDB - AUTO INCREMENT



The AUTO INCREMENT feature allows to create a unique numerical value for each additional record inserted into a table. Generally, it is used to create the numerical primary key field.

MariaDB AUTO_INCREMENT Keyword

In MariaDB, the AUTO_INCREMENT keyword is used to perform an auto-increment feature. For example - the below mentioned query creates a table called Employee which contains five columns: EmpID, Name, City, Age and Salary in which auto-increment is applied on column EmpID.

CREATE TABLE Employee (
  EmpID INT NOT NULL      AUTO_INCREMENT,
  Name VARCHAR(255),
  City VARCHAR(100),
  Age INT,
  Salary DECIMAL(18,2),
  PRIMARY KEY(EmpID)
);

By default, the start value of AUTO_INCREMENT is 1, and it is increased by 1 for each new record.

To change the start value of auto-increment, the below query can be used.

ALTER TABLE Employee AUTO_INCREMENT=50;

While inserting a new record, EmpID should not be specified. A unique value of EmpID will be added automatically.

INSERT INTO Employee (Name, City, Age, Salary)
VALUES ('John', 'London', 27, 2800);

The query mentioned above will insert a new record into the "Employee" table. The "EmpID" column will be assigned a unique value automatically. The "Name" column will be set to "John", the "City" column will be set to "London", the "Age" column will be set to 27 and the "Salary" column will be set to 2800.


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