我正在尝试动态绑定mysql_stmt参数并将结果放在关联数组中。我在stackoverflow上找到了这篇文章，其中Amber用以下代码发布了答案：
原帖： How to make a proper mysqli extension class with prepared statements?
“假设您实际上想要编写自己的版本（而不是使用其他答案所建议的现有库之一 - 这些也是很好的选择）......
以下是一些您可能会发现有用的功能。第一个允许您将查询的结果绑定到关联数组，第二个允许您传入两个数组，一个是有序的键数组，另一个是这些键的数据的关联数组，并将数据绑定到准备好的声明：“
function stmt_bind_assoc (&$stmt, &$out) {
$data = mysqli_stmt_result_metadata($stmt);
$fields = array();
$out = array();
$fields[0] = $stmt;
$count = 1;
while($field = mysqli_fetch_field($data)) {
$fields[$count] = &$out[$field->name];
$count++;
}
call_user_func_array(mysqli_stmt_bind_result, $fields);
}
function stmt_bind_params($stmt, $fields, $data) {
// Dynamically build up the arguments for bind_param
$paramstr = '';
$params = array();
foreach($fields as $key)
{
if(is_float($data[$key]))
$paramstr .= 'd';
elseif(is_int($data[$key]))
$paramstr .= 'i';
else
$paramstr .= 's';
$params[] = $data[$key];
}
array_unshift($params, $stmt, $paramstr);
// and then call bind_param with the proper arguments
call_user_func_array('mysqli_stmt_bind_param', $params);
}
我尝试研究代码以了解它的作用，并且我已经使第二个功能正常工作但我不知道我应该做些什么才能使用第一个功能。如何使用它来检索类似于mysqli_result :: fetch_assoc（）的数组？
我希望能够像以前那样使用结果：
while ($row = mysql_fetch_array($result)){
echo $row['foo']." ".$row['bar'];
}
请帮助我在这方面取得一些进展：）
答案 0 :(得分：13)
好的，这是一种方法：
编辑，修复获取多行时的错误
$sql = "SELECT `first_name`,`last_name` FROM `users` WHERE `country` =? AND `state`=?";
$params = array('Australia','Victoria');
/*
In my real app the below code is wrapped up in a class
But this is just for example's sake.
You could easily throw it in a function or class
*/
// This will loop through params, and generate types. e.g. 'ss'
$types = '';
foreach($params as $param) {
if(is_int($param)) {
$types .= 'i'; //integer
} elseif (is_float($param)) {
$types .= 'd'; //double
} elseif (is_string($param)) {
$types .= 's'; //string
} else {
$types .= 'b'; //blob and unknown
}
}
array_unshift($params, $types);
// Start stmt
$query = $this->connection->stmt_init(); // $this->connection is the mysqli connection instance
if($query->prepare($sql)) {
// Bind Params
call_user_func_array(array($query,'bind_param'),$params);
$query->execute();
// Get metadata for field names
$meta = $query->result_metadata();
// initialise some empty arrays
$fields = $results = array();
// This is the tricky bit dynamically creating an array of variables to use
// to bind the results
while ($field = $meta->fetch_field()) {
$var = $field->name;
$$var = null;
$fields[$var] = &$$var;
}
$fieldCount = count($fieldNames);
// Bind Results
call_user_func_array(array($query,'bind_result'),$fields);
$i=0;
while ($query->fetch()){
for($l=0;$l<$fieldCount;$l++) $results[$i][$fieldNames[$l]] = $fields[$fieldNames[$l]];
$i++;
}
$query->close();
// And now we have a beautiful
// array of results, just like
//fetch_assoc
echo "<pre>";
print_r($results);
echo "</pre>";
}
答案 1 :(得分：9)
如果只选择了一行，Emmanuel的答案就可以正常工作！如果查询选择多行，则$ results-Array为每一行保存结果，但结果始终用最后一个条目填充。 fetch（）稍有变化 - 虽然效果很好。
$ sqlStmt是一个字符串，填充了mysql-query
$ params是一个数组，填充了应传递的变量
$ results是一个空数组，用于保存结果
if (!is_string($sqlStmt) || empty($sqlStmt)) {
return false;
}
// initialise some empty arrays
$fields = array();
$results = array();
if ($stmt = $this->prepare($sqlStmt)) {
// bind params if they are set
if (!empty($params)) {
$types = '';
foreach($params as $param) {
// set param type
if (is_string($param)) {
$types .= 's'; // strings
} else if (is_int($param)) {
$types .= 'i'; // integer
} else if (is_float($param)) {
$types .= 'd'; // double
} else {
$types .= 'b'; // default: blob and unknown types
}
}
$bind_names[] = $types;
for ($i=0; $i<count($params);$i++) {
$bind_name = 'bind' . $i;
$$bind_name = $params[$i];
$bind_names[] = &$$bind_name;
}
call_user_func_array(array($stmt,'bind_param'),$bind_names);
}
// execute query
$stmt->execute();
// Get metadata for field names
$meta = $stmt->result_metadata();
// This is the tricky bit dynamically creating an array of variables to use
// to bind the results
while ($field = $meta->fetch_field()) {
$var = $field->name;
$$var = null;
$fields[$var] = &$$var;
}
// Bind Results
call_user_func_array(array($stmt,'bind_result'),$fields);
// Fetch Results
$i = 0;
while ($stmt->fetch()) {
$results[$i] = array();
foreach($fields as $k => $v)
$results[$i][$k] = $v;
$i++;
}
// close statement
$stmt->close();
}
答案 2 :(得分：1)
只是将@Emmanuel和@matzino的优秀答案与您在mysqli上选择PDO时可以获得的代码进行比较：
$sql = "SELECT `first_name`,`last_name` FROM `users` WHERE `country` =? AND `state`=?";
$params = array('Australia','Victoria');
$stm = $query->prepare($sql);
$stm->execute($params);
$results = $stm->fetchAll(); // or fetch() or fetchColumn() depends on expected type
哎呀，这就是全部？
答案 3 :(得分：1)
使用上面的答案后，我发现自己需要进行一些清理工作，特别是'fieldNames []'部分。下面的代码是程序式的。我希望它会对某人有用。
我从我制作的可以动态查询数据的类中删除了代码。我删除了一些内容以便于阅读。在我的类中，我允许用户定义定义表和外键，以便限制前端的数据输入以及所述相关数据的过滤和排序选项。这些是我删除的所有参数以及自动查询构建器。
$query = "SELECT `first_name`,`last_name` FROM `users` WHERE `country` =? AND `state`=?";
$params = array('Australia','Victoria');
////////////// GENERATE PARAMETER TYPES IF ANY //////////////
// This will loop through parameters, and generate types. ex: 'ss'
$types = '';
$params_size = sizeof($params);
if($params_size > 0)
{
foreach($params as $param)
{
if(is_int($param))
{
$types .= 'i'; //integer
}else if(is_float($param))
{
$types .= 'd'; //double
}else if(is_string($param))
{
$types .= 's'; //string
}else
{
$types .= 'b'; //blob and unknown
}
}
array_unshift($params, $types);
}
////////////////////////////////////////////////////////////
// This is the tricky part to dynamically create an array of
// variables to use to bind the results
//below from http://php.net/manual/en/mysqli-result.fetch-field.php
/*
name The name of the column
orgname Original column name if an alias was specified
table The name of the table this field belongs to (if not calculated)
orgtable Original table name if an alias was specified
def Reserved for default value, currently always ""
db Database (since PHP 5.3.6)
catalog The catalog name, always "def" (since PHP 5.3.6)
max_length The maximum width of the field for the result set.
length The width of the field, as specified in the table definition.
charsetnr The character set number for the field.
flags An integer representing the bit-flags for the field.
type The data type used for this field
decimals The number of decimals used (for integer fields)
*/
/// FIELD TYPE REFERENCE ///
/*
numerics
-------------
BIT: 16
TINYINT: 1
BOOL: 1
SMALLINT: 2
MEDIUMINT: 9
INTEGER: 3
BIGINT: 8
SERIAL: 8
FLOAT: 4
DOUBLE: 5
DECIMAL: 246
NUMERIC: 246
FIXED: 246
dates
------------
DATE: 10
DATETIME: 12
TIMESTAMP: 7
TIME: 11
YEAR: 13
strings & binary
------------
CHAR: 254
VARCHAR: 253
ENUM: 254
SET: 254
BINARY: 254
VARBINARY: 253
TINYBLOB: 252
BLOB: 252
MEDIUMBLOB: 252
TINYTEXT: 252
TEXT: 252
MEDIUMTEXT: 252
LONGTEXT: 252
*/
if($stmt = mysqli_prepare($db_link, $query))
{
// BIND PARAMETERS IF ANY //
if($params_size > 0)
{
call_user_func_array(array($stmt, 'bind_param'), makeValuesReferenced($params));
}
mysqli_stmt_execute($stmt);
$meta = mysqli_stmt_result_metadata($stmt);
$field_names = array();
$field_length = array();
$field_type = array();
$output_data = array();
/// THIS GET THE NAMES OF THE FIELDS AND ASSIGNS NEW VARIABLES USING THE FIELD NAME. THESE VARIABLES ARE THEN SET TO NULL ///
$count = 0;
while($field = mysqli_fetch_field($meta))
{
$field_names[$count] = $field->name;// field names
$var = $field->name;
$$var = null;
$field_names_variables[$var] = &$$var;// fields variables using the field name
$field_length[$var] = $field->length;// field length as defined in table
$field_type[$var] = $field->type;// field data type as defined in table (numeric return)
$count++;
}
setFieldLengthInfo($field_length);
setFieldTypesInfo($field_type);
$field_names_variables_size = sizeof($field_names_variables);
call_user_func_array(array($stmt, 'bind_result'), $field_names_variables);
$count = 0;
while(mysqli_stmt_fetch($stmt))
{
for($l = 0; $l < $field_names_variables_size; $l++)
{
$output_data[$count][$field_names[$l]] = $field_names_variables[$field_names[$l]];/// THIS SETS ALL OF THE FINAL DATA USING THE DYNAMICALLY CREATED VARIABLES ABOVE
}
$count++;
}
mysqli_stmt_close($stmt);
echo "<pre>";
print_r($output_data);
echo "</pre>";
}
function makeValuesReferenced($arr)
{
$refs = array();
foreach($arr as $key => $value)
$refs[$key] = &$arr[$key];
return $refs;
}