PHP get Array(s) when is directly defined in $string - php

Question

When is Array defined in string (like in sample below), is possible get the information of this Arrays?
$id = 1;
$query =
"
SELECT *
FROM category
WHERE
id > " . [$id, 'int'] . " AND
title LIKE " . ['%test%', 'str'] . "
ORDER BY id ASC
";
$select = sql ($query);
var_dump($query) // output
//SELECT * FROM category WHERE id > Array AND title LIKE Array ORDER BY id ASC
/*
var_dump ($query->my_defined_arrays_are)
[0] => 1
[1] => '%test%'
*/
i need this for better orientation in most complex queries for $sql->bind_param();
SOLUTION:
I created small function bind() which create and store the bind data and then send it to the sql() function where are processed. This works on all queries types (SELECT, INSERT, UPDATE, DELETE..etc.).
Important for me is clear and easy readable code.
Query:
$query =
"
SELECT *
FROM category
WHERE
id > " . bind('1', 'int') . " AND
title LIKE " . bind('%test%', 'str') . "
ORDER BY id ASC
";
$select = sql ($query, $bind);
/*
var_dump ($query)
SELECT * FROM category WHERE id > {Bind_Array} AND title LIKE {Bind_Array} ORDER BY id ASC
*/
Functions:
function bind($param, $type) {
global $bind;
$bind[] = $param . ', ' . $type;
return '{Bind_Array}';
}
function sql($query, $bind_param = []) {
global $settings, $bind;
$bind = null; // clean variable; must be empty for all next operations
$mysqli = new mysqli (
$settings['db_hostname'],
$settings['db_username'],
$settings['db_password'],
$settings['db_database']
);
if ($mysqli->connect_errno) {
echo 'Failed to connect to MySQL: (' . $mysqli->connect_errno . ') ' . $mysqli->connect_error;
return;
}
if (!$mysqli->set_charset('utf8')) {
echo 'Error loading character set utf8: (' . $mysqli->character_set_name() . ') ' . $mysqli->error;
return;
}
if ($bind_param != null) {
unset ($tmp_bind, $tmp_type);
// reserve first key
$tmp_bind[0] = null;
// replace all occurences string in query
$query = preg_replace ('/({Bind_Array})/', ' ?', $query);
// create parameters from array
foreach ($bind_param as $params) {
// explode and clean parametres
$param = array_map ('trim', explode (',', $params));
if (count ($param) != 2) {
echo 'Too much or less parameters!';
return;
}
// first is content
$tmp_bind[] = $param[0];
// second is type; create right format
$tmp_type .= str_replace (array ('int', 'str', 'double'), array ('i', 's', 'd'), $param[1]);
}
// set types to the first reserved key
$tmp_bind[0] = $tmp_type;
// replace previdous incoming data with new created
$bind_param = $tmp_bind;
}
if (!($sql = $mysqli->prepare($query))) {
echo 'Prepare failed: (' . $mysqli->errno . ') ' . $mysqli->error;
$mysqli->close();
return;
}
if (!empty ($bind_param) && $type = array_shift ($bind_param)) {
// $sql->bind_param()
call_user_func_array (array ($sql, 'bind_param'), array_merge (array ($type), array_map (function (&$item) { return $item; }, $bind_param)));
}
if (!$sql->execute()) {
echo 'Execute failed: (' . $sql->errno . ') ' . $sql->error;
$sql->close();
return;
}
if (strpos ($query, 'SELECT ') !== false || strpos ($query, 'SHOW ') !== false) {
// proceed this only if is SELECT or SHOW query
if (!($res = $sql->get_result())) {
echo 'Getting result set failed: (' . $sql->errno . ') ' . $sql->error;
$res->close();
return;
}
// store data to $output for use
for ($row_no = ($res->num_rows - 1); $row_no >= 0; $row_no --) {
$res->data_seek($row_no);
$output[$row_no] = $res->fetch_assoc();
}
$res->close();
}
$sql->close();
unset ($tmp_bind);
return $output;
}

Answer 1

The answer to your question is "No". When you add an array to a string, you get a string, and the original array is lost in the string "Array".
So -- why are you doing this?
My guess is that you're trying to come up with a compact representation of a query - a single object containing information on the query and its parameters (if any). This can be done, but requires some code to go with it.
For example you can create a class of your own holding the query in PDO format, with placeholders:
SELECT * FROM category WHERE id > :param1 ...
and also an array of parameters with their types:
[ 'param1' => 'int', ... ]
Then you might need a __toString() method to yield a string representation that is of use for you. The above representation can immediately be used by PDO.
Now, to specify a query with its parameters, you can use a compact representation not too unlike the one you used, leveraging an array of arrays (note that there is no string concatenation here, but rather array concatenation):
$query = ["SELECT * FROM tbl WHERE id >",['int']," AND ..." ...];
To convert from this "shorthand" to the more useable PDO_String / PDO_Param_Array representation, you could walk $query concatenating all non-string elements with placeholder parameters:
$queryString = '';
$queryParams = [ ];
$n = 1;
foreach ($query as $item) {
if (is_string($item)) {
$queryString .= $item;
} else {
$queryString .= ':param' . $n;
$queryParams[":param{$n}"] = $item[0];
$n++;
}
}