pg_query

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

pg_query执行查询

说明

pg_query(PgSql\Connection $connection = ?, string $query): PgSql\Result|false

pg_query() 在特定数据库 connection 上执行 querypg_query_params() 在大多数情况下应该是首选。

如果发生错误并返回 false,那么在连接有效时可以使用 pg_last_error() 函数检索错误的详细信息。

注意: 尽管可以省略 connection,但不建议这样做,因为可能会导致脚本中的错误难以发现。

注意:

本函数以前的名字为 pg_exec()pg_exec() 因为兼容性原因仍可使用,但鼓励用户使用新名称。

参数

connection

An PgSql\Connection instance. When connection is unspecified, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().

警告

As of PHP 8.1.0, using the default connection is deprecated.

query

要执行的 SQL 语句。当多个语句传递给函数时,将作为一个事务自动执行,除非查询字符串中包含明确的 BEGIN/COMMIT 命令。但是,不建议在一个函数调用中使用多个事务。

警告

用户提供的数据作为字符串插入值非常危险,很可能导致 SQL 注入漏洞。在大多数情况下,应该首选 pg_query_params(),将用户提供的值作为参数传递,而不是将它们替换为查询字符串。

任何用户提供的数据,都应该正确转义,然后直接替换为查询字符串。

返回值

成功时为 PgSql\Result 实例, 或者在失败时返回 false

更新日志

版本 说明
8.1.0 现在返回 PgSql\Result 实例,之前返回 resource
8.1.0 现在 connection 参数接受 PgSql\Connection 实例,之前接受 resource

示例

示例 #1 pg_query() 示例

<?php

$conn
= pg_pconnect("dbname=publisher");
if (!
$conn) {
echo
"An error occurred.\n";
exit;
}

$result = pg_query($conn, "SELECT author, email FROM authors");
if (!
$result) {
echo
"An error occurred.\n";
exit;
}

while (
$row = pg_fetch_row($result)) {
echo
"Author: $row[0] E-mail: $row[1]";
echo
"<br />\n";
}

?>

示例 #2 使用多条语句的 pg_query()

<?php

$conn
= pg_pconnect("dbname=publisher");

// 这些语句将作为一个事务执行

$query = "UPDATE authors SET author=UPPER(author) WHERE id=1;";
$query .= "UPDATE authors SET author=LOWER(author) WHERE id=2;";
$query .= "UPDATE authors SET author=NULL WHERE id=3;";

pg_query($conn, $query);

?>

参见

添加备注

用户贡献的备注 9 notes

up
5
a dot mcruer at live dot com
12 years ago
A quick note for novice users: when gathering input from fields on a web form that maintains a database connection, *never* use pg_query to do queries from the field. Always sanitize input using pg_prepare and pg_execute.
up
4
zoli at makettinfo.hu
19 years ago
It would be better this way:<?php  $result=pg_query($conn, "SELECT COUNT(*) AS rows FROM x WHERE a=b;");  if  (!$result) {   echo "query did not execute";  }  if ($line = pg_fetch_assoc($result)) {    if ($line['rows'] == 0) {     echo "0 records"    }  }  else {   while ($row = pg_fetch_array($result)) {     //do stuff with $row   }  }?> This solution doesn't raise the load of the system with the move of matching rows (perhaps 0,1, perhaps 100, 1000, ... rows)
up
4
jsuzuki at spamcop dot net
19 years ago
expanding on the note left by "cmoore" -To check to see if the recordset returned no records,<?php  $result=pg_query($conn, "SELECT * FROM x WHERE a=b;");  if  (!$result) {    echo "query did not execute";  }  $rs = pg_fetch_assoc($result);  if (!$rs) {    echo "0 records"  }?>-jack
up
2
mentat at azsoft dot pl
22 years ago
$GLOBALS["PG_CONNECT"]=pg_connect(...);....function query ($sqlQuery,$var=0) {   if (!$GLOBALS["PG_CONNECT"]) return 0;   $lev=error_reporting (8); //NO WARRING!!   $result=pg_query ($sqlQuery);   error_reporting ($lev); //DEFAULT!!   if (strlen ($r=pg_last_error ($GLOBALS["PG_CONNECT"]))) {      if ($var) {        echo "<p color=\"red\">ERROR:<pre>";        echo $sqlQuery;        echo "</pre>";        echo $r;        echo "&lt/p>";      }      close_db ();      return 0;   }   return $result;}
up
1
cmoore
19 years ago
One thing to note that wasn't obvious to me at first.  If your query returns zero rows, that is not a "failed" query.  So the following is wrong:  $result=pg_query($conn, "SELECT * FROM x WHERE a=b;");  if  (!$result) {    echo "No a=b in x\n";  }pg_query returns FALSE if the query can not be executed for some reason.  If the query is executed but returns zero rows then you get back a resul with no rows.
up
0
mankyd
19 years ago
There was a typo in the code that I posted:<?php  $result=pg_query($conn, "SELECT * FROM x WHERE a=b;");  if  (!$result) {   echo "query did not execute";  }  if (pg_num_rows($result) == 0) {   echo "0 records"  }  else {   while ($row = pg_fetch_array($result)) {     //do stuff with $row   }  }?>
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-1
Akbar
20 years ago
Use pg_query to call your stored procedures, and use pg_fetch_result when getting a value (like a smallint as in this example) returned by your stored procedure.<?php$pgConnection = pg_connect("dbname=users user=me");$userNameToCheckFor = "metal";$result = pg_query($pgConnection, "SELECT howManyUsersHaveThisName('$userNameToCheckFor')");$count = pg_fetch_result($result, 0, 'howManyUsersHaveThisName');?>
up
-2
mankyd
19 years ago
Improving upon what jsuzuki said:It's probably better to use pg_num_rows() to see if no rows were returned, as that leaves the resultset cursor pointed to the first row so you can use it in a loop.Example:<?php  $result=pg_query($conn, "SELECT * FROM x WHERE a=b;");  if  (!$result) {   echo "query did not execute";  }  if (pg_num_rows($result) == 0) {   echo "0 records"  }  else {    while ($row = pg_fetch_array($result) {      //do stuff with $row    }  }?>I, personally, also find it more readable.
up
-2
Anonymous
11 years ago
Here is my small function to make it easier for me to use data from select queries (attention, it is sensitive to sql injection)<?phpfunction requestToDB($connection,$request){     if(!$result=pg_query($connection,$request)){        return False;    }    $combined=array();    while ($row = pg_fetch_assoc($result)) {        $combined[]=$row;    }    return $combined;}?>Example:<?php$conn = pg_pconnect("dbname=mydatabase");$results=requestToDB($connect,"select * from mytable");//You can now access a "cell" of your table like this:$rownumber=0;$columname="mycolumn";$mycell=$results[$rownumber][$columname];var_dump($mycell);
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