Question

我正在尝试编写准备好的语句以供用户输入。参数号是可变的，取决于用户输入。我正在尝试此代码

php代码：

$string          = "my name";
$search_exploded = explode( " ", $string );
$num             = count( $search_exploded );
$cart            = array();
for ( $i = 1; $i <= $num; $i ++ ) {
    $cart[] = 's';
}
$str          = implode( '', $cart );
$inputArray[] = &$str;
$j            = count( $search_exploded );
for ( $i = 0; $i < $j; $i ++ ) {
    $inputArray[] = &$search_exploded[ $i ];
}
print_r( $inputArray );
foreach ( $search_exploded as $search_each ) {
    $x ++;
    if ( $x == 1 ) {
        $construct .= "name LIKE %?%";
    } else {
        $construct .= " or name LIKE %?%";
    }
}
$query = "SELECT * FROM info WHERE $construct";
$stmt  = mysqli_prepare( $conn, $query );
call_user_func_array( array( $stmt, 'bind_param' ), $inputArray );
if ( mysqli_stmt_execute( $stmt ) ) {

    $result = mysqli_stmt_get_result( $stmt );
    if ( mysqli_num_rows( $result ) > 0 ) {
        echo $foundnum = mysqli_num_rows( $result );
        while( $row = mysqli_fetch_array( $result, MYSQLI_ASSOC ) ) {

            echo $id = $row['id'];
            echo $name = $row['name'];
        }
    }
}

当我print_r $ inputArray输出是这样的时候：

   Array ( [0] => ss [1] => my [2] => name )

错误日志中没有错误显示。我在这里做什么错了，请告诉我。

Answer 1

100％经过测试/成功的代码：

%包装使用参数而不是占位符。（有关其他说明，请参见嵌入式注释）

$string = " b c ";

$strings = array_unique(preg_split('~\s+~', $string, -1, PREG_SPLIT_NO_EMPTY));  // isolate and remove duplicates
$where = '';
$types = '';
foreach ($strings as $s) {
    $params[] = "%{$s}%";  // wrap values in percent signs for LIKE
    $where .= (!$where ? " WHERE" : " OR") . " name LIKE ?";  // build clause
    $types .= 's';
}
// echo "<div>{$where}</div>";  // uncomment if you wish to see what is generated

if (!$conn = new mysqli("host", "user", "pass", "db")) {
    echo "Database Connection Error: " , $conn->connect_error;
} else {
    $query = "SELECT id, name FROM info{$where}";
    if(!$stmt = $conn->prepare($query)) {
        echo "Syntax Error @ prepare: " , $conn->error;  // don't show to public
    }else{
        if ($where) {
            array_unshift($params, $types);  // prepend the type values string
            $ref = [];  // add references
            foreach ($params as $i => $v) {
                $ref[$i] = &$params[$i];  // pass by reference as required/advised by the manual
            }
            call_user_func_array([$stmt, 'bind_param'], $ref);
        }    

        if (!$stmt->execute()) {
            echo "Error @ bind_param/execute: " , $stmt->error;  // don't show to public
        } elseif (!$stmt->bind_result($id, $name)) {
            echo "Error @ bind_result: " , $stmt->error;  // don't show to public
        } else {
            while ($stmt->fetch()) {
                echo "<div>$id : $name</div>"; 
            }
            $stmt->close();
        }
    }
}

Answer 2

编写一个通用查询处理程序，并将查询，参数数组和参数类型列表传递给它。获取一系列结果或消息。这是我自己的mysqli个人版本（我主要使用PDO，但也为此设置了类似的功能）。对插入，更新和删除执行相同的操作。然后只需维护您的一个库并将其用于您做的所有事情：）请注意，如果以此为起点，您可能希望做得更好，以处理连接错误等。

<?php

// this is normally in an include() file
function getDBConnection(){

    // your DB credentials

    $hostname="127.0.0.1";
    $username="ausername";
    $password="supersecret";
    $database="some_db_name";

    $con = new mysqli($hostname, $username,$password, $database);
    if($con->connect_error) {
      return false;
    }
    return $con;
}

// generic select function.
// takes a query string, an array of parameters, and a string of
// parameter types
// returns an array - 
//   if $retVal[0] is true, query was successful and returned data
//   and $revVal[1...N] contain the results as an associative array
//   if $retVal[0] is false, then $retVal[1] either contains the 
//   message "no records returned" OR it contains a mysql error message

function selectFromDB($query,$params,$paramtypes){

    // intitial return;
    $retVal[0]=false;

    // establish connection
    $con = getDBConnection();
    if(!$con){
        die("db connection error");
        exit;
    }

    // sets up a prepared statement
    $stmnt=$con->prepare($query);
    $stmnt->bind_param($paramtypes, ...$params);
    $stmnt->execute();

    // get our results
    $result=$stmnt->get_result()->fetch_all(MYSQLI_ASSOC);
    if(!$result){
    $retVal[1]="No records returned";
    }else{
        $retVal[0]=true;
        for($i=0;$i<count($result);$i++){
            $retVal[]=$result[$i];
        }
    }

    // close the connection
    $con->close();

    return $retVal;

}

$myusername=$_POST['username'];
$mypassword=$_POST['password'];

// our query, using ? as positional placeholders for our parameters
$q="SELECT useridnum,username FROM users WHERE username=? and password=?";

// our parameters as an array - 
$p=array($myusername,$mypassword);

// what data types are our params? both strings in this case
$ps="ss";

// run query and get results
$result=selectFromDB($q,$p,$ps);

// no matching record OR a query error
if(!$result[0]){
    if($result[1]=="no records returned"){
        // no records
        // do stuff
    }else{
        // query error
        die($result[1]);
        exit;
    }   
}else{  // we  have matches!
    for($i=1;$i<count($result);$i++){
        foreach($result[$i] as $key->$val){
            print("key:".$key." -> value:".$val);
        }
    }
}

?>

如何使用准备好的语句动态绑定参数？

2 个答案: