AUTO INCREMENT (automatic growth) generates a unique number when a new record is inserted into the table.
PostgreSQL uses sequences to identify the self-growth of fields. The data types are smallserial, serial, and bigserial. These properties are similar to the AUTO_INCREMENT properties supported by the MySQL database.
The statements that use MySQL to set auto-growth are as follows:
CREATE TABLE IF NOT EXISTS `runoob_tbl`(
`runoob_id` INT UNSIGNED AUTO_INCREMENT,
`runoob_title` VARCHAR(100) NOT NULL,
`runoob_author` VARCHAR(40) NOT NULL,
`submission_date` DATE,
PRIMARY KEY ( `runoob_id` )
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
MySQL is used
AUTO_INCREMENT
This property identifies the self-increment of the field.
PostgreSQL uses sequences to identify the self-growth of fields:
CREATE TABLE runoob
(
id serial NOT NULL,
alttext text,
imgurl text
)
SMALLSERIAL
、
SERIAL
And
BIGSERIAL
Range:
Pseudo type | Storage size | Range |
|---|---|---|
| 2 byt | 1 to 32767 |
| 4 byt | 1 to 2147483647 |
| 8 byte | 1 to 922 people 337 people 2036854775807 |
5.41.1. Grammar ¶
SERIAL
The basic syntax of the data type is as follows:
CREATE TABLE tablename (
colname SERIAL
);
5.41.2. Example ¶
Suppose we are going to create a
COMPANY
Table and create the following fields:
runoobdb=# CREATE TABLE COMPANY(
ID SERIAL PRIMARY KEY,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
Now insert a few records into the table:
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'Paul', 32, 'California', 20000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ('Allen', 25, 'Texas', 15000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ('Teddy', 23, 'Norway', 20000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'Mark', 25, 'Rich-Mond ', 65000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'David', 27, 'Texas', 85000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'Kim', 22, 'South-Hall', 45000.00 );
INSERT INTO COMPANY (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'James', 24, 'Houston', 10000.00 );
View
COMPANY
The record of the table is as follows:
id | name | age | address | salary
----+-------+-----+------------+--------
1 | Paul | 32 | California | 20000
2 | Allen | 25 | Texas | 15000
3 | Teddy | 23 | Norway | 20000
4 | Mark | 25 | Rich-Mond | 65000
5 | David | 27 | Texas | 85000
6 | Kim | 22 | South-Hall | 45000
7 | James | 24 | Houston | 10000