Simple MySQLi Query

An extremely simple MySQLi query class for prepared statements.

Get started

To initialize a new instance of the Query class, simply pass in your mysqli object:

$mysqli = new mysqli('127.0.0.1', 'my_user', 'my_password', 'my_db');

if ($mysqli->connect_error) {
    die('Connect Error (' . $mysqli->connect_errno . ') ' . $mysqli->connect_error);
}

$query = new Query($mysqli);

For more information about creating a new connection, see: https://www.php.net/manual/en/mysqli.construct.php

Usage

This class is made up of the following methods:

• select() - Simple select statements
• insert() - Simple insert statements
• update() - Simple update statements
• delete() - Simple delete statements
• query() - Simple queries, accepting bind_param parameter types

The first 4 methods automatically convert their parameter values to their corresponding data types for the bind_param method.

The supported types for this class are converted by using the gettype() value of the variable, into the bind_param type using the table below:

Type	Character	Description
string	s	corresponding variable has type string
null	s	corresponding variable has type string
integer	i	corresponding variable has type integer
float	d	corresponding variable has type double

For more information about bind_param types, see: https://www.php.net/manual/en/mysqli-stmt.bind-param.php#refsect1-mysqli-stmt.bind-param-parameters

Out of the CRUD methods, the select() method is the only method that returns an array - the data to be returned. The rest simply return a boolean based on whether the query was able to successfully insert, update, or delete.

Query examples

Select

A simple SELECT statement, with no parameters:

$data = $query->select('SELECT * FROM `pets`');

return $data;

A simple SELECT statement, with parameters:

$params = [
    'M',
];

$data = $query->select('SELECT * FROM `pets` WHERE `sex` = ?', $params);

return $data;

Insert

A simple INSERT statement:

$params = [
    'Thumper',
    'Sabrina',
    'Mini Lop',
    'M',
    '2020-08-22',
];

$return = $query->insert('INSERT INTO `pets` VALUES (?, ?, ?, ?, ?)');

return $return;

Update

A simple UPDATE statement:

$params = [
    'Oliver',
    'Thumper',
];

$return = $query->insert('UPDATE `pets` SET `owner` = ? WHERE `name` = ?');


return $return;

Delete

A simple DELETE statement:

$params = [
    'Thumper',
];

$return = $query->insert('DELETE FROM `pets` WHERE `name` = ?', $params);

return $return;

Advanced usage

For more advanced usages, you can use the query() method directly:

$types = 'ss';

$params = [
    '2020-01-01',
    '2020-12-31',
];

$data = $query->query('SELECT * FROM `pets` WHERE `death` BETWEEN ? AND ?', $types, $params);

return $data;

You may want to use this method to gain more control over the bind_param types, without having this class attempt to convert them for you.

Table structure

The above examples are given as an example. If you would like to use this exact table structure to test these examples directly, you can create this yourself by using the following CREATE TABLE statement:

CREATE TABLE `pets` (
  `name` VARCHAR(20),
  `owner` VARCHAR(20),
  `species` VARCHAR(20),
  `sex` CHAR(1),
  `birth` DATE,
  `death` DATE
);

Which would look something like this, using a DESCRIBE statement:

+---------+-------------+------+-----+---------+-------+
| Field   | Type        | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| name    | varchar(20) | YES  |     | NULL    |       |
| owner   | varchar(20) | YES  |     | NULL    |       |
| species | varchar(20) | YES  |     | NULL    |       |
| sex     | char(1)     | YES  |     | NULL    |       |
| birth   | date        | YES  |     | NULL    |       |
| death   | date        | YES  |     | NULL    |       |
+---------+-------------+------+-----+---------+-------+

Primary keys, indexes and character sets have been removed for simplicity. The table structure itself was taken directly from the MySQL 'Creating Tables' documentation.