PHP连接及操作PostgreSQL数据库的方法详解

更新时间：2020-04-02 03:47:49 作者：startmvc

本文实例讲述了PHP连接及操作PostgreSQL数据库的方法。分享给大家供大家参考，具体如下：Po

本文实例讲述了PHP连接及操作PostgreSQL数据库的方法。分享给大家供大家参考，具体如下：

PostgreSQL扩展在默认情况下在最新版本的PHP 5.3.x中是启用的。可以在编译时使用--without-pgsql来禁用它。仍然可以使用yum命令来安装PHP-PostgreSQL接口：


yum install php-pgsql

在开始使用PHP连接PostgreSQL接口之前，请先在PostgreSQL安装目录中找到pg_hba.conf文件，并添加以下行：


# IPv4 local connections:
host all all 127.0.0.1/32 md5

您可以启动/重新启动postgres服务器，使用以下命令运行：


[root@host]# service postgresql restart
Stopping postgresql service: [ OK ]
Starting postgresql service: [ OK ]

Windows用户必须启用php_pgsql.dll才能使用此扩展名。这个DLL包含在最新版本的PHP 5.3.x中的Windows发行版中。

PHP连接到PostgreSQL数据库

以下PHP代码显示如何连接到本地机器上的现有数据库，最后将返回数据库连接对象。


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } else {
 echo "Opened database successfully\n";
 }
?>

现在，让我们运行上面的程序打开数据库:testdb，如果成功打开数据库连接，那么它将给出以下消息：

Opened database successfully

创建表

以下PHP程序将用于在之前创建的数据库(testdb)中创建一个表：


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } 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;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 } else {
 echo "Table created successfully\n";
 }
 pg_close($db);
?>

当执行上述程序时，它将在testdb数据库中创建COMPANY表，并显示以下消息：

Opened database successfully Table created successfully

SQL

插入操作

以下PHP程序显示了如何在上述示例中创建的COMPANY表中创建记录：


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } 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;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 } else {
 echo "Records created successfully\n";
 }
 pg_close($db);
?>

当执行上述程序时，它将在COMPANY表中创建给定的记录，并显示以下两行：

Opened database successfully Records created successfully

SELECT操作

以下PHP程序显示了如何从上述示例中创建的COMPANY表中获取和显示记录：


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } else {
 echo "Opened database successfully\n";
 }
 $sql =<<<EOF
 SELECT * from COMPANY;
EOF;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 exit;
 }
 while($row = pg_fetch_row($ret)){
 echo "ID = ". $row[0] . "\n";
 echo "NAME = ". $row[1] ."\n";
 echo "ADDRESS = ". $row[2] ."\n";
 echo "SALARY = ".$row[4] ."\n\n";
 }
 echo "Operation done successfully\n";
 pg_close($db);
?>

当执行上述程序时，将产生以下结果。请记下，在创建表时按照它们使用的顺序返回字段。

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

更新操作

以下PHP代码显示了如何使用UPDATE语句来更新指定记录，然后从COMPANY表中获取并显示更新的记录：


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } else {
 echo "Opened database successfully\n";
 }
 $sql =<<<EOF
 UPDATE COMPANY set SALARY = 25000.00 where ID=1;
EOF;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 exit;
 } else {
 echo "Record updated successfully\n";
 }
 $sql =<<<EOF
 SELECT * from COMPANY;
EOF;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 exit;
 }
 while($row = pg_fetch_row($ret)){
 echo "ID = ". $row[0] . "\n";
 echo "NAME = ". $row[1] ."\n";
 echo "ADDRESS = ". $row[2] ."\n";
 echo "SALARY = ".$row[4] ."\n\n";
 }
 echo "Operation done successfully\n";
 pg_close($db);
?>

执行上述程序时，会产生以下结果：

Opened database successfully Record updated successfully ID = 2 NAME = Allen ADDRESS = 25 SALARY = 15000 ID = 3 NAME = Teddy ADDRESS = 23 SALARY = 20000 ID = 4 NAME = Mark ADDRESS = 25 SALARY = 65000 ID = 1 NAME = Paul ADDRESS = 32 SALARY = 25000 Operation done successfully

删除操作

以下PHP代码显示了如何使用DELETE语句删除指定记录，然后从COMPANY表中获取并显示剩余的记录：


<?php
 $host = "host=127.0.0.1";
 $port = "port=5432";
 $dbname = "dbname=testdb";
 $credentials = "user=postgres password=pass123";
 $db = pg_connect( "$host $port $dbname $credentials" );
 if(!$db){
 echo "Error : Unable to open database\n";
 } else {
 echo "Opened database successfully\n";
 }
 $sql =<<<EOF
 DELETE from COMPANY where ID=2;
EOF;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 exit;
 } else {
 echo "Record deleted successfully\n";
 }
 $sql =<<<EOF
 SELECT * from COMPANY;
EOF;
 $ret = pg_query($db, $sql);
 if(!$ret){
 echo pg_last_error($db);
 exit;
 }
 while($row = pg_fetch_row($ret)){
 echo "ID = ". $row[0] . "\n";
 echo "NAME = ". $row[1] ."\n";
 echo "ADDRESS = ". $row[2] ."\n";
 echo "SALARY = ".$row[4] ."\n\n";
 }
 echo "Operation done successfully\n";
 pg_close($db);
?>

执行上述程序时，会产生以下结果：

Opened database successfully Record deleted successfully ID = 3 NAME = Teddy ADDRESS = 23 SALARY = 20000 ID = 4 NAME = Mark ADDRESS = 25 SALARY = 65000 ID = 1 NAME = Paul ADDRESS = 32 SALARY = 25000 Operation done successfully