How to find a database row that matches a string? - php

Question

I have a databse table with 100K rows and an array of 100 items. And I need to find if an array item is found in my Users table username row.
My database table Users
| id | username | fullname |
1 John John Smith
2 Elliot Jim Elliot
3 Max Max Richard
My array looks like this
[
{
string: 'Hello, this is Elliot from downtown Las Vegas!'
},
{
string: 'Hey how are you?'
}
]
My idea was to do a foreach loop through every row in my Users table (100k records) and find if it matches in my array, but it is so slow.
foreach ($MyArray as $Array) {
foreach ($dbrows as $dbrow) {
if (strpos($Array['string'], $dbrow['username']) !== false) {
echo 'found it!';
break;
}
}
}

Answer 1

It will be a bit hit and miss as you may find users with all sorts of weird names that match normal words, this approach splits the input into words and then uses them to form an in clause to search the database. So it only looks at records that match rather than all records...
$search = 'Hello, this is Elliot from downtown Las a1 Vegas!';
$words = str_word_count($search, 1);
$bind = str_repeat("?,", count($words));
$bind = trim($bind, ",");
$query = $conn->prepare("select * from users where username in ($bind)" );
$types = str_repeat("s", count($words));
$query->bind_param($types, ...$words);
$query->execute();
$res = $query->get_result();
while($row = $res->fetch_assoc()) {
// Process result
}
It also uses prepared statements, which is where all of the $bind and $types processing comes in. If you look at $query you will see how it's built up.

Answer 2

I think the better way was to separate your search arrays into words, and use it in the query, like:
<?php
// Assuming your search array is $search...
$words = array ();
foreach ( $search as $text)
{
$words = array_merge ( $words, explode ( " ", trim ( preg_replace ( "/[^0-9a-z]+/i", " ", $text))));
}
$words = array_unique ( $words);
$in = "";
foreach ( $words as $text)
{
$in .= ",'" . $mysqli->real_escape_string ( $text) . "'";
}
if ( ! $result = $mysqli->query ( "SELECT * FROM `Users` WHERE `username` IN (" . substr ( $in, 1) . ")"))
{
echo "MySQL error!";
}
// Results at $result
?>

Answer 3

You can use regular expressions:
<?php
$query_string = "bla bla bla...";
$qry = $mysqli_query($conn, "SELECT *FROM table WHERE username REGEXP '$query_string'");
?>
Regular expression matches data individually from table.