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PostgreSQL連接PHP

編輯：PostgreSQL

安裝

PostgreSQL的擴展是默認啟用的最新版本的PHP5.3.x.但是它可能通過在編譯時加上--without-pgsql 選項禁用。但仍然可以使用yum命令安裝PHP的PostgreSQL的接口：

yum install php-pgsql

在開始使用PHP PostgreSQL接口，打開pg_hba.conf文件(在PostgreSQL安裝目錄)，並添加下面一行：

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

使用start/restart啟動Postgres服務器，它沒有運行使用下面的命令：

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

Windows用戶必須啟用php_pgsql.dll為了使用這個擴展。這個DLL包含帶Windows分布在最新版本PHP5.3.x

有關詳細的安裝說明，請查看我們的PHP教程和其官方網站上。

PHP 接口APIs

以下是重要的PHP程序，可以連接使用PostgreSQL數據庫PHP程序。如果正在尋找一個更復雜的應用程序，那麼可以看看到PHP官方文件。

S.N. API & 描述 1 resource pg_connect ( string $connection_string [, int $connect_type ] )

這將打開一個連接到PostgreSQL數據庫由connection_string指定。

如果PGSQL_CONNECT_FORCE_NEW會傳遞為connect_type，然後在第二個調用的情況下，對pg_connect（）創建一個新的連接，即使connection_string一個現有的連接是相同的。

2 bool pg_connection_reset ( resource $connection )

此例程重置連接。它是有用的錯誤恢復。成功返回TRUE或失敗則返回FALSE。

3 int pg_connection_status ( resource $connection )

這個例程返回指定的連接狀態。返回PGSQL_CONNECTION_OK或PGSQL_CONNECTION_BAD。

4 string pg_dbname ([ resource $connection ] )

這個例程返回給定的PostgreSQL數據庫連接資源的名稱。

5 resource pg_prepare ([ resource $connection ], string $stmtname , string $query )

提交請求以創建具有給定參數的准備好的語句，並等待完成。

6 resource pg_execute ([ resource $connection ], string $stmtname , array $params )

這個程序發送一個請求給定的參數執行准備好的語句，並等待結果。

7 resource pg_query ([ resource $connection ], string $query )

此程序執行查詢指定的數據庫連接。

8 array pg_fetch_row ( resource $result [, int $row ] )

該例程將指定的結果的資源相關聯的，數據從結果中獲取一個行。

9 array pg_fetch_all ( resource $result )

這個例程返回一個數組，包含所有行（記錄），結果資源。

10 int pg_affected_rows ( resource $result )

這個例程返回INSERT，UPDATE和DELETE查詢受到影響的行數。

11 int pg_num_rows ( resource $result )

這個例程返回的行數，例如SELECT語句返回的行數在一個PostgreSQL結果資源。

12 bool pg_close ([ resource $connection ] )

該例程關閉非持久連接到一個給定的連接資源相關的PostgreSQL數據庫。

13 string pg_last_error ([ resource $connection ] )

這個例程返回的最後一個錯誤消息，對於一個給定的連接。

14 string pg_escape_literal ([ resource $connection ], string $data )

此例程轉義文字插入一個文本字段。

15 string pg_escape_string ([ resource $connection ], string $data )

這例程轉義一個字符串查詢數據庫。

連接到數據庫

下面的PHP代碼顯示了如何連接到一個現有的在本地機器上的數據庫，最後將返回一個數據庫連接對象。

<?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
";
   } else {
      echo "Opened database successfully
";
   }
?>

現在讓我們運行上面的程序來打開數據庫testdb，如果成功打開數據庫，然後它會給下面的消息：

Opened database successfully

創建表

下面的PHP程序將使用以前創建的數據庫中創建一個表：

<?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
";
   } else {
      echo "Opened database successfully
";
   }
   
   $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($db);
   } else {
      echo "Table created successfully
";
   }
   pg_close($db);
?>

上述程序執行時，它會創建表COMPANY在數據庫testdb 中，它會顯示以下消息：

Opened database successfully
Table created successfully

INSERT操作

PHP程序，顯示我們如何創建表COMPANY 在上面的例子中，創建表中的記錄：

<?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
";
   } else {
      echo "Opened database successfully
";
   }

   $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($db);
   } else {
      echo "Records created successfully
";
   }
   pg_close($db);
?>

上述程序執行時，它會創建COMPANY表中的記錄，並會顯示以下兩行：

Opened database successfully
Records created successfully

SELECT 操作

PHP程序表明我們如何獲取並顯示COMPANY 在上面的例子中創建表的記錄：

<?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
";
   } else {
      echo "Opened database successfully
";
   }

   $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] . "
";
      echo "NAME = ". $row[1] ."
";
      echo "ADDRESS = ". $row[2] ."
";
      echo "SALARY =  ".$row[4] ."

";
   }
   echo "Operation done successfully
";
   pg_close($db);
?>

當上述程序執行時，它會產生以下結果。字段返回序列中，它們被用來創建表的同時保持注意。

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代碼顯示了如何我們可以使用UPDATE語句來更新任何記錄，然後獲取並顯示更新的記錄，從COMPANY 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
";
   } else {
      echo "Opened database successfully
";
   }
   $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
";
   }
   
   $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] . "
";
      echo "NAME = ". $row[1] ."
";
      echo "ADDRESS = ". $row[2] ."
";
      echo "SALARY =  ".$row[4] ."

";
   }
   echo "Operation done successfully
";
   pg_close($db);
?>

當上述程序執行時，它會產生以下結果：

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

DELETE 操作

下面的PHP代碼，表明我們如何能夠使用DELETE語句刪除任何記錄，然後獲取並顯示COMPANY 表剩余的記錄：

<?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
";
   } else {
      echo "Opened database successfully
";
   }
   $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
";
   }
   
   $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] . "
";
      echo "NAME = ". $row[1] ."
";
      echo "ADDRESS = ". $row[2] ."
";
      echo "SALARY =  ".$row[4] ."

";
   }
   echo "Operation done successfully
";
   pg_close($db);
?>

當上述程序執行時，它會產生以下結果：

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