关于使用数据库连接在 PHP 中编程时什么是最好的，我有一个一般性的问题。我正在构建一个包含多个模块的项目，每个模块有时都需要连接到 MySQL。根据用户从菜单中选择的操作，模块文件包含在主 index.php 中。我想，无论如何，大多数项目都是这样工作的。
到目前为止，我所做的总是在每个模块文件的开头打开连接，并在查询运行后关闭它。
我的问题是：最好在 index.php 的开头打开与数据库的连接并在最后关闭它以便打开 1 个连接，还是做多个保持打开时间更短的连接？什么最适合速度和开销？
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163 次
2 回答
1
正如 NB 所指出的，您可能应该设置一个类来处理所有与数据库相关的任务。我从我的代码档案中发布了一个片段来说明如何设置这样的类。这仅用于说明目的，如果您只是复制和粘贴，则不保证对您有用。它可能需要一些改进。它还利用 smarty 类来处理数据视图。
我建议去掉你不需要的东西。设置您的 MySQL 连接参数。在您的索引文件中，您可以实例化一个 SQL 对象并简单地调用适当的方法。这些方法返回并将结果保存为关联数组和索引数组。遍历表行很简单：
$SQL->GetRows('RowTemplate.tpl', 'StoredProcedure', 'Parameters');
仅供参考，这是更大的 $Portal 框架对象的一部分，以防您想知道 $Portal 引用是什么。$SQL 只是扩展了 $Portal。
我希望这有帮助。祝你好运
class SQL {
/********** MEMBER VARIABLES **********************************************************************/
var $Connection; // DB connection handler
var $Result; // ResultSet returned from last call during life of object instance
var $RowCount; // RowCount for ResultSet returned from last call during life of object instance
var $ResultArray; // ResultSet Array returned from last call during life of object instance
var $Query; // Query last submitted during life of object instance
var $ErrorNumber; // Error number for error returned from last call during life of object instance
var $Error; // Error returned from last call during life of object instance
var $Message; // Messages returned during life of object instance
// Switches, flags, markers, etc
var $DebugMode;
var $LogActive;
var $ShowErrorMsg;
// Modules array
var $Modules;
// SQL Connection Info - PROTECTED!
protected $Host = "localhost";
protected $User = "mydatabase";
protected $Password = "mypassword";
protected $Schema = "myschema";
/********** MEMBER FUNCTIONS **********************************************************************/
// Object Constructor
function __construct() {
// Automatically open DB Connection
//$this->OpenDBConnection();
//echo "User Object Constructor<br>";
}
// Open new DB Connection
function OpenDBConnection() {
return ($this->Connection = mysqli_connect($this->Host, $this->User, $this->Password, $this->Schema))? true : false;
}
// Close DB Connection
function CloseDBConnection() {
mysqli_close($this->Connection);
//return true;
}
// Return error messages
function GetError() {
return $this->Error;
}
// Return last query string
function GetQuery() {
return $this->Query;
}
// Call, execute stored procedure and return result set
/* NOTES: The result set is always returned as an int array of associative arrays
That is, if $Result was returned, the first row would be referenced as $Result[0]
and any column of the first row would be referenced as $Result[0]['ColumnName']
COMMENTS: */
function CallProcedure($StoredProcedure) {
// Clear any System Errors
$this->ErrorNumber = '';
$this->Error = '';
// Open DB Connection
if(!$this->OpenDBConnection()) return false;
// Kill error if there are no extra Params passed
$Params = @func_get_arg(1);
// Build Query
$this->Query = "CALL $StoredProcedure ($Params)";
//if($this->Result = $this->Connection->query($this->Query)) {
if($this->Result = mysqli_query($this->Connection, $this->Query)) {
// Reset global Result Set
$this->ResultArray = Array();
// Set record count for current record set
$this->RowCount = 0;
while($Row = @mysqli_fetch_array($this->Result, MYSQLI_BOTH)) {
$this->ResultArray[$this->RowCount] = $Row;
$this->RowCount++;
}
// Close DB Connection
$this->CloseDBConnection();
return $this->ResultArray;
}
// Grab Error
$this->ErrorNumber = mysqli_errno($this->Connection);
$this->Error = mysqli_error($this->Connection);
// Close DB Connection
$this->CloseDBConnection();
return false;
}
/* Using Smarty class, return row template filled with record set from given stored procedure
EXAMPLE 1: Primary Function - Using data set from stored procedure
$Portal->SQL->GetRows('RowTemplate.tpl', 'StoredProcedure', 'Parameters');
EXAMPLE 2: Secondary Function - Using data set in second dimensional associative array
$Portal->SQL->GetRows('RowTemplate.tpl', 'ARRAY', $MyDataSetArray); */
function GetRows($RowTemplate, $Procedure) {
// Kill error if there are no extra Params passed
$Parameters = @func_get_arg(2);
// Set return string
$ReturnString = '';
// If Procedure is ARRAY then params are data set else Call procedure and return results array
$Result = ($Procedure=='ARRAY')? $Parameters : $this->CallProcedure($Procedure, $Parameters);
// Loop through result set initializing smarty obj for each row
$Count = 0;
while(IsSet($Result[$Count])) {
$RowTemplateObj = new Smarty;
$RowTemplateObj->assign('SCRIPT_NAME', SCRIPT_NAME);
$RowTemplateObj->assign('HOST_NAME', HOST_NAME);
// Loop though each result row as an associative array of column - values
foreach ($Result[$Count] as $Key => $Value) {
if(IsSet($Result[$Count][$Key])) $RowTemplateObj->assign($Key, (is_array($Value))?$Value:stripslashes($Value));
//if(IsSet($Result[$Count][$Key])) $RowTemplateObj->assign($Key, $Value);
}
$RowTemplateObj->assign('bgcolor', '{$bgcolor'. ($Count%2 + 1) .'}');
// Concatenate populated row into return string
$ReturnString .= $RowTemplateObj->fetch($RowTemplate);
$Count++;
}
return $ReturnString;
}
function GetSelectList($Procedure, $Parameters, $OptionValueField, $OptionNameField) {
// Kill error if there are no extra Params passed
$Selected = @func_get_arg(4);
// Set return string
$ReturnString = '';
// Get List Resultset
$Result = $this->CallProcedure($Procedure, $Parameters);
// Loop through result set and set <option> ta row
$Count = 0;
while(IsSet($Result[$Count])) {
$ReturnString .= '<option value="'.$Result[$Count][$OptionValueField].'"';
$ReturnString .= ($Selected==$Result[$Count][$OptionValueField])? ' selected ' : '';
$ReturnString .= '>'.$Result[$Count][$OptionNameField].'</option>';
$Count++;
}
return $ReturnString;
}
function Execute($SQL) {
// Clear any System Errors
$this->ErrorNumber = '';
$this->Error = '';
// Open DB Connection
if(!$this->OpenDBConnection()) return false;
// Assign Query
$this->Query = $SQL;
if($this->Result = mysqli_query($this->Connection, $this->Query)) {
// Reset global Result Set
$this->ResultArray = Array();
// Set record count for current record set
$this->RowCount = 0;
while($Row = @mysqli_fetch_array($this->Result, MYSQLI_BOTH)) {
$this->ResultArray[$this->RowCount] = $Row;
$this->RowCount++;
}
// Close DB Connection
$this->CloseDBConnection();
return $this->ResultArray;
}
// Grab Error
$this->ErrorNumber = mysqli_errno($this->Connection);
$this->Error = mysqli_error($this->Connection);
// Close DB Connection
$this->CloseDBConnection();
return false;
}
于 2012-10-19T17:33:20.277 回答
-3
在同一个文件中建立单独的连接并根据它们关闭它们。
/ * ****门户1的连接** * *** /
$portal1_link = mysql_connect('localhost','root','') or die('无法连接到数据库'); mysql_select_db('mylekha_auction',$portal1_link) or die('无法选择数据库');
/ * ****门户2的连接** * *** /
$portal2_link = mysql_connect('localhost','root','') or die('无法连接到数据库'); mysql_select_db('mylekha_auction',$portal2_link) or die('无法选择数据库');
于 2012-10-17T09:53:49.527 回答