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PostgreSQL PHP 接口
安装
PostgreSQL 扩展在最新版本的 PHP 5.3.x 中默认启用。可以在编译时使用--without-pgsql禁用它。我们仍然可以使用 yum 命令安装 PHP -PostgreSQL 接口
yum install php-pgsql
在开始使用 PHP PostgreSQL 界面之前，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
可以使用以下命令启动/重新启动 postgres 服务器，以防它没有运行 -
[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。此 DLL 包含在最新版本的 PHP 5.3.x 中的 Windows 发行版中
连接到数据库
以下 PHP 代码展示了如何连接到本地机器上的现有数据库，最终将返回一个数据库连接对象。
<?php
$host = "host = 127.0.0.1";
$port = "port = 5432";
$dbname = "dbname = jiyik_db";
$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来打开我们的数据库 jiyik_db：如果数据库成功打开，它将给出以下消息 -
Opened database successfully
创建表
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 = jiyik_db";
$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);
?>
当上面给定的程序被执行时，它会在你的 jiyik_db 中创建 COMPANY 表，它会显示以下消息 -
Opened database successfully
Table created successfully
插入操作
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 = jiyik_db";
$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
选择操作
以下 PHP 程序展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 = jiyik_db";
$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);
?>
当上面给出的程序被执行时，它会产生下面的结果。请注意，字段按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
更新操作
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 表中获取并显示更新的记录 -
<?php
$host = "host=127.0.0.1";
$port = "port=5432";
$dbname = "dbname = jiyik_db";
$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);
?>
当上面给定的程序被执行时，它会产生以下结果
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 代码显示了我们如何使用 DELETE 语句删除任何记录，然后从我们的 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 = jiyik_db";
$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);
?>
当上面给定的程序被执行时，它会产生以下结果
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
