sqlite常用語法

在終端下運行sqlite3 <*.db>，出現如下提示符：
SQLite version 3.7.2
Enter “.help” for instructions
Enter SQL statements terminated with a “;”
sqlite>
<*.db> 是要打開的數據庫文件。若該文件不存在，則自動創建。 
顯示所有命令 
sqlite> .help
退出sqlite3
sqlite>.quit
顯示當前打開的數據庫文件 
sqlite>.database
顯示數據庫中所有表名 
sqlite>.tables
查看錶的結構 
sqlite>.schema <table_name>
/*******************************************/ 
以下爲SQL命令，每個命令以;結束 
創建新表 
>create table <table_name> (f1 type1, f2 type2,…);
sqlite> create table student(no integer primary key, name text, score real); 
刪除表 
sqlite>drop table <table_name>
sqlite>drop table student 
查詢表中所有記錄 
sqlite>select * from <table_name>; 
按指定條件查詢表中記錄 
sqlite>select * from <table_name> where <expression>； 
sqlite> select * from student 
sqlite> select * from student where name=’zhao’
sqlite> select * from student where name=’zhao’ and score >=95
sqlite> select count(*) from student where score>90 
向表中添加新記錄 
sqlite>insert into <table_name> values (value1, value2,…);
sqlite> insert into student values(1, ‘zhao’, 92); 
按指定條件刪除表中記錄 
sqlite>delete from <table_name> where <expression>
sqlite> delete from student where score<60; 
更新表中記錄 
sqlite>update <table_name> set <f1=value1>, <f2=value2>… where <expression>; 
sqlite> update student set score=0;
sqlite> update student set name=’sun’ where no=3; 
在表中添加字段 
sqlite>alter table <table> add column <field> <type>; 
sqlite> alter table student add column gender integer default 0; 
在表中刪除字段 
Sqlite中不允許刪除字段，可以通過下面步驟達到同樣的效果
sqlite> create table stu as select no, name, score from student
sqlite> drop table student
sqlite> alter table stu rename to student