SQLite Autoincrement（自动递增）
SQLite AUTOINCREMENT是用于自动递增表中字段值的关键字。我们可以使用AUTOINCREMENT关键字在创建具有特定列名的表时自动递增字段值。
关键字 AUTOINCREMENT 只能与INTEGER字段一起使用。
语法
AUTOINCREMENT关键字的基本用法如下-
CREATE TABLE table_name( column1 INTEGER AUTOINCREMENT, column2 datatype, column3 datatype, ..... columnN datatype, );
在线示例
考虑如下创建的COMPANY表-
sqlite> CREATE TABLE COMPANY( ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL);
现在，将以下记录插入表COMPANY-
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 );这将在表COMPANY中插入7个元组，并且COMPANY将具有以下记录-
ID NAME AGE ADDRESS SALARY---------- ---------- ---------- ---------- ----------1 Paul 32 California 20000.02 Allen 25 Texas 15000.03 Teddy 23 Norway 20000.04 Mark 25 Rich-Mond 65000.05 David 27 Texas 85000.06 Kim 22 South-Hall 45000.07 James 24 Houston 10000.0