SQLite - PHP

青旅半醒 2022-09-22 12:58 143阅读 0赞

## 安装 ##

自 PHP 5.3.0 起默认启用 SQLite3 扩展。可以在编译时使用 **--without-sqlite3** 禁用 SQLite3 扩展。

Windows 用户必须启用 php\_sqlite3.dll 才能使用该扩展。自 PHP 5.3.0 起，这个 DLL 被包含在 PHP 的 Windows 分发版中。

如需了解详细的安装指导，建议查看我们的 PHP 教程和它的官方网站。

## PHP 接口 API ##

以下是重要的 PHP 程序，可以满足您在 PHP 程序中使用 SQLite 数据库的需求。如果您需要了解更多细节，请查看 PHP 官方文档。

<table style="border:0px; margin:4px 0px; padding:0px; border-collapse:collapse; width:729px; color:rgb(51,51,51); font-family:&quot;Open Sans&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,STHeiti,&quot;Microsoft Yahei&quot;,sans-serif; font-size:12px"> 
 <tbody style="border:0px; margin:0px; padding:0px"> 
 <tr style="border:0px; margin:0px; padding:0px; background-color:rgb(246,244,240)"> 
 <th style="border:1px solid rgb(85,85,85); margin:0px; padding:3px; color:rgb(255,255,255); vertical-align:top; background-color:rgb(85,85,85)"> 序号</th> 
 <th style="border:1px solid rgb(85,85,85); margin:0px; padding:3px; color:rgb(255,255,255); vertical-align:top; background-color:rgb(85,85,85)"> API &amp; 描述</th> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 1</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public void SQLite3::open ( filename, flags, encryption_key ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 打开一个 SQLite 3 数据库。如果构建包括加密，那么它将尝试使用的密钥。 <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 如果文件名&nbsp;filename&nbsp;赋值为&nbsp;':memory:'，那么 SQLite3::open() 将会在 RAM 中创建一个内存数据库，这只会在 session 的有效时间内持续。 <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 如果文件名 filename 为实际的设备文件名称，那么 SQLite3::open() 将使用这个参数值尝试打开数据库文件。如果该名称的文件不存在，那么将创建一个新的命名为该名称的数据库文件。 <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 可选的 flags 用于判断是否打开 SQLite 数据库。默认情况下，当使用 SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE 时打开。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px; background-color:rgb(246,244,240)"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 2</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public bool SQLite3::exec ( string $query ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程提供了一个执行 SQL 命令的快捷方式，SQL 命令由 sql 参数提供，可以由多个 SQL 命令组成。该程序用于对给定的数据库执行一个无结果的查询。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 3</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public SQLite3Result SQLite3::query ( string $query ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程执行一个 SQL 查询，如果查询到返回结果则返回一个&nbsp;SQLite3Result&nbsp;对象。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px; background-color:rgb(246,244,240)"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 4</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public int SQLite3::lastErrorCode ( void ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程返回最近一次失败的 SQLite 请求的数值结果代码。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 5</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public string SQLite3::lastErrorMsg ( void ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程返回最近一次失败的 SQLite 请求的英语文本描述。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px; background-color:rgb(246,244,240)"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 6</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public int SQLite3::changes ( void ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程返回最近一次的 SQL 语句更新或插入或删除的数据库行数。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 7</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public bool SQLite3::close ( void ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程关闭之前调用 SQLite3::open() 打开的数据库连接。 </td> 
 </tr> 
 <tr style="border:0px; margin:0px; padding:0px; background-color:rgb(246,244,240)"> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> 8</td> 
 <td style="border:1px solid rgb(212,212,212); margin:0px; padding:7px 5px; font-size:1em; vertical-align:top"> public string SQLite3::escapeString ( string $value ) <p style="border:0px; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; line-height:2em; font-family:&quot;Microsoft Yahei&quot;,&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif"> 该例程返回一个字符串，在 SQL 语句中，出于安全考虑，该字符串已被正确地转义。 </td> 
 </tr> 
 </tbody> 
</table>

## 连接数据库 ##

下面的 PHP 代码显示了如何连接到一个现有的数据库。如果数据库不存在，那么它就会被创建，最后将返回一个数据库对象。

现在，让我们来运行上面的程序，在当前目录中创建我们的数据库 **test.db**。您可以根据需要改变路径。如果数据库成功创建，那么会显示下面所示的消息：

Open database successfully

## 创建表 ##

下面的 PHP 代码段将用于在先前创建的数据库中创建一个表：

<?php
 class MyDB extends SQLite3
 {
 
 function __construct()
 {
 
 $this->open('test.db');
 }
 }
 $db = new MyDB();
 if(!$db){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Opened database successfully\n";
 }
 
 $sql =<<<EOF
 CREATE TABLE COMPANY
 (ID INT PRIMARY KEY NOT NULL,
 NAME TEXT NOT NULL,
 AGE INT NOT NULL,
 ADDRESS CHAR(50),
 SALARY REAL);
 EOF;
 
 $ret = $db->exec($sql);
 if(!$ret){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Table created successfully\n";
 }
 $db->close();
 ?>

上述程序执行时，它会在 **test.db** 中创建 COMPANY 表，并显示下面所示的消息：

Opened database successfully
    Table created successfully

## INSERT 操作 ##

下面的 PHP 程序显示了如何在上面创建的 COMPANY 表中创建记录：

<?php
 class MyDB extends SQLite3
 {
 
 function __construct()
 {
 
 $this->open('test.db');
 }
 }
 $db = new MyDB();
 if(!$db){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Opened database successfully\n";
 }
 
 $sql =<<<EOF
 INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
 VALUES (1, 'Paul', 32, 'California', 20000.00 );
 
 INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
 VALUES (2, 'Allen', 25, 'Texas', 15000.00 );
 
 INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
 VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );
 
 INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)
 VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );
 EOF;
 
 $ret = $db->exec($sql);
 if(!$ret){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Records created successfully\n";
 }
 $db->close();
 ?>

上述程序执行时，它会在 COMPANY 表中创建给定记录，并会显示以下两行：

Opened database successfully
    Records created successfully

## SELECT 操作 ##

下面的 PHP 程序显示了如何从前面创建的 COMPANY 表中获取并显示记录：

<?php
 class MyDB extends SQLite3
 {
 
 function __construct()
 {
 
 $this->open('test.db');
 }
 }
 $db = new MyDB();
 if(!$db){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Opened database successfully\n";
 }
 
 $sql =<<<EOF
 SELECT * from COMPANY;
 EOF;
 
 $ret = $db->query($sql);
 while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
 
 echo "ID = ". $row['ID'] . "\n";
 echo "NAME = ". $row['NAME'] ."\n";
 echo "ADDRESS = ". $row['ADDRESS'] ."\n";
 echo "SALARY = ".$row['SALARY'] ."\n\n";
 }
 echo "Operation done successfully\n";
 $db->close();
 ?>

上述程序执行时，它会产生以下结果：

Opened database successfully
    ID = 1
    NAME = Paul
    ADDRESS = California
    SALARY =  20000
    
    ID = 2
    NAME = Allen
    ADDRESS = Texas
    SALARY =  15000
    
    ID = 3
    NAME = Teddy
    ADDRESS = Norway
    SALARY =  20000
    
    ID = 4
    NAME = Mark
    ADDRESS = Rich-Mond
    SALARY =  65000
    
    Operation done successfully

## UPDATE 操作 ##

下面的 PHP 代码显示了如何使用 UPDATE 语句来更新任何记录，然后从 COMPANY 表中获取并显示更新的记录：

<?php
 class MyDB extends SQLite3
 {
 
 function __construct()
 {
 
 $this->open('test.db');
 }
 }
 $db = new MyDB();
 if(!$db){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Opened database successfully\n";
 }
 $sql =<<<EOF
 UPDATE COMPANY set SALARY = 25000.00 where ID=1;
 EOF;
 $ret = $db->exec($sql);
 if(!$ret){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo $db->changes(), " Record updated successfully\n";
 }
 
 $sql =<<<EOF
 SELECT * from COMPANY;
 EOF;
 $ret = $db->query($sql);
 while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
 
 echo "ID = ". $row['ID'] . "\n";
 echo "NAME = ". $row['NAME'] ."\n";
 echo "ADDRESS = ". $row['ADDRESS'] ."\n";
 echo "SALARY = ".$row['SALARY'] ."\n\n";
 }
 echo "Operation done successfully\n";
 $db->close();
 ?>

上述程序执行时，它会产生以下结果：

Opened database successfully
    1 Record updated successfully
    ID = 1
    NAME = Paul
    ADDRESS = California
    SALARY =  25000
    
    ID = 2
    NAME = Allen
    ADDRESS = Texas
    SALARY =  15000
    
    ID = 3
    NAME = Teddy
    ADDRESS = Norway
    SALARY =  20000
    
    ID = 4
    NAME = Mark
    ADDRESS = Rich-Mond
    SALARY =  65000
    
    Operation done successfully

## DELETE 操作 ##

下面的 PHP 代码显示了如何使用 DELETE 语句删除任何记录，然后从 COMPANY 表中获取并显示剩余的记录：

<?php
 class MyDB extends SQLite3
 {
 
 function __construct()
 {
 
 $this->open('test.db');
 }
 }
 $db = new MyDB();
 if(!$db){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo "Opened database successfully\n";
 }
 $sql =<<<EOF
 DELETE from COMPANY where ID=2;
 EOF;
 $ret = $db->exec($sql);
 if(!$ret){
 
 echo $db->lastErrorMsg();
 } else {
 
 echo $db->changes(), " Record deleted successfully\n";
 }
 
 $sql =<<<EOF
 SELECT * from COMPANY;
 EOF;
 $ret = $db->query($sql);
 while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
 
 echo "ID = ". $row['ID'] . "\n";
 echo "NAME = ". $row['NAME'] ."\n";
 echo "ADDRESS = ". $row['ADDRESS'] ."\n";
 echo "SALARY = ".$row['SALARY'] ."\n\n";
 }
 echo "Operation done successfully\n";
 $db->close();
 ?>

上述程序执行时，它会产生以下结果：

Opened database successfully
    1 Record deleted successfully
    ID = 1
    NAME = Paul
    ADDRESS = California
    SALARY =  25000
    
    ID = 3
    NAME = Teddy
    ADDRESS = Norway
    SALARY =  20000
    
    ID = 4
    NAME = Mark
    ADDRESS = Rich-Mond
    SALARY =  65000
    
    Operation done successfully