SQLite Autoincrement

SQLite Autoincrement（自动递增）SQLite 的 AUTOINCREMENT 是一个关键字，用于表中的字段值自动递增。我们可以在创建表时在特定的列名称上使用 AUTOINCREMENT 关键字实现该字段值的自动增加。关键字 AUTOINCREMENT 只能用于整型（INTEGER）字段。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,);实例假设要创建的 COMPANY 表如下所示：sqlite> CREATE TABLE COMPANY( ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INT NOT NULL, ADDRESS CHAR(50), SALARY REAL);现在，向 COMPANY 表插入以下记录：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 );这将向 COMPANY 表插入 7 个元组，此时 COMPANY 表的记录如下：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