mysqli prepared statements with IN operator and one more placeholder

问题

I have some confusion in my code please view my code and suggest me how to pass another parameter in query using with In operator.

$cat=1;
$lastnames = $ids;
$arParams = array();

foreach($lastnames as $key => $value) 
        $arParams[] = &$lastnames[$key];
        ;

$count_params = count($arParams);
$int = str_repeat('i',$count_params); 
array_unshift($arParams,$int); 
$q = array_fill(0,$count_params,'?'); 
$params = implode(',',$q);

$qry1=$dblink->prepare("SELECT * FROM course_details WHERE category=$cat and cat_id IN ($params)");
call_user_func_array(array($qry1, 'bind_param'), $arParams);
$qry1->execute();
$qry1_res=$qry1->get_result();

while($rowset1=$qry1_res->fetch_array()){
    print_r($rowset1);
}

I can't bind my cat id as like preapred. please help me Thank you

回答1:

A slight variation on Your Common Sense's answer, and something I didn't realise you could do (although it makes sense in a way)...

$cat=1;
$lastNames = $ids;

$count_params = count($lastNames);
$int = str_repeat('i',$count_params+1);
$q = array_fill(0,$count_params,'?');
$params = implode(',',$q);
$qry1=$dblink->prepare("SELECT * FROM course_details WHERE category=? and cat_id IN ( $params )");

$qry1->bind_param( $int, $cat, ...$lastNames);
$qry1->execute();
$qry1_res=$qry1->get_result();
while($rowset1=$qry1_res->fetch_array()){
        print_r($rowset1);
}

The only real different is the call to bind_param, rather than merging the item into the array, just list it as another parameter before using the array fill (...) from PHP 5.6+.

Update: From the comment, the version of PHP doesn't support splat :(... so going back to original...

$cat=1;
$lastnames = $ids;
$arParams = array();

array_unshift($lastnames,$cat);
foreach($lastnames as $key => $value)   {
    $arParams[] = &$lastnames[$key];
}

$count_params = count($arParams);
$int = str_repeat('i',$count_params);
array_unshift($arParams,$int);
$q = array_fill(0,$count_params-1,'?');
$params = implode(',',$q);

$qry1=$dblink->prepare("SELECT * FROM course_details WHERE category=? and cat_id IN ( $params )");
call_user_func_array(array($qry1, 'bind_param'), $arParams);
$qry1->execute();
$qry1_res=$qry1->get_result();

while($rowset1=$qry1_res->fetch_array()){
    print_r($rowset1);
}

This adds the category into the list of items, but note the array_fill() uses count-1 as the ? for the cat is already there.

回答2:

Not tested but perhaps you could fudge it a little like this

$cat=1;
$lastnames = $ids;
$arParams = array();

foreach( $lastnames as $key => $value ) $arParams[ $key ] = &$lastnames[ $key ];




$count_params = count( $arParams );


$int = str_repeat( 'i', $count_params + 1 ); /* add one more type string */
array_unshift( $arParams, $int ); 

$q = array_fill(0,$count_params,'?'); /* add ? for each param */
$params = implode(',', $q );

/* add $cat as first parameter */
array_unshift( $arParams, $cat );



$qry1=$dblink->prepare("SELECT * FROM course_details WHERE category=? and cat_id IN ( $params )");
call_user_func_array( array( $qry1, 'bind_param' ), &$arParams );


$qry1->execute();
$qry1_res=$qry1->get_result();

while( $rowset1=$qry1_res->fetch_array() ){
    print_r( $rowset1 );
}

回答3:

Thanks to splat operator and some other tricks the code could be sensibly shortened to a handful of rows:

$qmarks = str_repeat('?,', count($ids) - 1) . '?';
$types  = str_repeat('i',  count($ids) + 1);
$params = array_merge(array($cat), $ids);
$sql = "SELECT * FROM course_details WHERE category=? and cat_id IN ($qmarks)";
$stmt = $dblink->prepare($sql);
$stmt->bind_param($types, ...$params);
$data = $stmt->get_result()->fetch_all(MYSQL_ASSOC);

foreach ($data as $row){
    print_r($row);
}

although Nigel Ren offered a real neat solution, sparing an array_merge() call, I would stick with mine for it being more universal, allowing other placeholders not only in front but also past the IN() statement. Those could be merged into the final $params array as well

来源：https://stackoverflow.com/questions/49106012/mysqli-prepared-statements-with-in-operator-and-one-more-placeholder

标签

php

mysqli