默认情况下，在最新版本的PHP 5.3.x中启用了PostgreSQL扩展.可以在编译时使用 - without-pgsql 禁用它.仍然可以使用yum命令安装PHP -PostgreSQL接口 :
yum install php-pgsql
在开始使用PHP PostgreSQL界面之前，找到PostgreSQL安装目录中的 pg_hba.conf 文件并添加以下行 :
# IPv4 local connections: host all all 127.0.0.1/32 md5
你可以启动/重启postgres服务器，万一它没有运行，使用以下命令 :
[root@host]# service postgresql restart Stopping postgresql service: [ OK ] Starting postgresql service: [ OK ]
Windows用户必须按顺序启用php_pgsql.dll使用此扩展程序.此DLL包含在最新版本的PHP 5.3.x中的Windows发行版中.
有关详细的安装说明，请查看我们的PHP教程及其官方网站.
以下是重要的PHP例程，它们可以满足您从PHP程序使用PostgreSQL数据库的要求.如果您正在寻找更复杂的应用程序，那么您可以查看PHP官方文档.
| S.不. | API&描述 |
|---|---|
| 1 | 资源pg_connect(字符串$ connection_string [，int $ connect_type]) 这将打开与指定的PostgreSQL数据库的连接connection_string. 如果PGSQL_CONNECT_FORCE_NEW作为connect_type传递，则在第二次调用pg_connect()时会创建一个新连接，即使connection_string与现有连接相同. |
| 2 | bool pg_connection_reset(resource $ connection) 此例程重置连接.它对错误恢复很有用.成功时返回TRUE，失败时返回FALSE. |
| 3 | int pg_connection_status(resource $ connection) 这个例程返回指定连接的状态.返回PGSQL_CONNECTION_OK或PGSQL_CONNECTION_BAD. |
| 4 | 字符串pg_dbname([resource $ connection]) 此例程返回给定PostgreSQL连接资源的数据库名称. |
| 5 | 资源pg_prepare([resource $ connection]，string $ stmtname，string $ query) 这提交了一个创建带有给定参数的预准备语句的请求，并等待完成. |
| 6 | 资源pg_execute ([resource $ connection]，string $ stmtname，array $ params) 此例程发送请求以执行带有给定参数的预准备语句并等待结果. |
| 7 | 资源pg_query([resource $ connection]， string $ query) 此例程对指定的数据库连接执行查询. |
| 8 | 数组pg_fetch_row (resource $ result [，int $ row]) 此例程从与指定结果资源关联的结果中提取一行数据. |
| 9 | 数组pg_fetch_all(资源$ result) 此例程返回一个数组，其中包含结果资源中的所有行(记录). |
| 10 | int pg_affected_rows(resource $ result) 此例程返回受I影响的行数NSERT，UPDATE和DELETE查询. |
| 11 | int pg_num_rows(resource $ result) 此例程返回PostgreSQL结果资源中的行数，例如SELECT语句返回的行数. |
| 12 | bool pg_close([resource $ connection]) 此例程关闭与给定连接资源关联的PostgreSQL数据库的非持久连接. |
| 13 | string pg_last_error([resource $ connection]) 此例程返回给定连接的最后一条错误消息. |
| 14 | 取值tring pg_escape_literal([resource $ connection]，string $ data) 此例程转义文字以插入文本字段. |
| 15 | string pg_escape_string([resource $ connection]，string $ data) 此例程转义字符串以查询数据库. |
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，让我们运行上面给出的程序打开我们的数据库 testdb :如果数据库成功打开，那么它将会给出以下消息 :
Opened database successfully
以下PHP程序将用于在先前创建的数据库中创建表 :
<?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);
?>当执行上述给定程序时，它将在 testdb 中创建COMPANY表，它将显示以下消息 :
成功打开数据库 表成功创建
以下PHP程序显示了我们如何在上面示例中创建的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);
?>执行上述给定程序时，它将在COMPANY表中创建给定记录，并显示以下两行 :
Opened database successfully Records created successfully
以下PHP程序显示了我们如何从上面示例中创建的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);
?>执行上述给定程序时，将产生以下结果.请注意，字段按照创建表时使用的顺序返回.
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
以下PHP代码显示了我们如何使用UPDATE语句更新任何记录，然后从我们的COMPANY表中删除并显示更新的记录 :
<?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);
?>当执行上面给出的程序时，它将产生以下结果 :
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
以下PHP代码显示了我们如何使用DELETE语句删除任何记录然后获取并显示我们的COMPANY表中的剩余记录 :
<?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);
?>当执行上面给出的程序时，它将产生以下结果 :
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
