Get mysql database schema - php

Question

Is it possible to get the full structure of a mySQL database in json or xml format?
what I'm looking for is a way to get the schema (stored data doesn't matter) to use it to create a backend/crud for the application.

Answer 1

This is not a fully comprehensive answer to the question, as it doesn't return a json. But it's a simple class that gives all relevant info about a table as an object. This could easily be transformed to return a json.
The class relies on having passed a db object that implements a rawQuery method, as PHP-Mysqli-Database-Class does. But you could easily rewrite the method extractTableInfo if you need.
<?php
Class dbHelper {
private $db;
public function __construct($db) {
$this->db = $db;
}
public function extractTableInfo($tableName) {
$result = $this->db->rawQuery("DESCRIBE `".$tableName."`");
$tableInfo = array();
foreach ($result as $key => $value) {
$info = new \stdClass();
$info->name = $value['Field'];
$info->type = $this->_getColumnType($value['Type']);
$info->length = $this->_getLength($value['Type']);
$info->hasNull = $this->_getNull($value['Null']);
$info->default = $this->_getDefault($value['Default']);
$tableInfo[] = $info;
}
return $tableInfo;
}
public function getIndexes($tableName) {
$result = $this->db->rawQuery("SHOW INDEX FROM `".$tableName."`");
return $result;
}
private function _getLength($info) {
$pattern = '/\({1}([\d\W]*)\){1}/';
preg_match($pattern, $info, $matches);
return isset($matches[1]) ? $matches[1] : NULL;
}
private function _getColumnType($info) {
$pattern = '/([\w]*)(\([\d\W]*\))*/';
preg_match($pattern, $info, $matches);
return isset($matches[1]) ? $matches[1] : NULL;
}
private function _getNull($info) {
if($info==='NO') {
return false;
} else {
return true;
}
}
private function _getDefault($info) {
if($info>='') {
return $info;
} else {
return NULL;
}
}
}
Usage:
$db = YOUR DATABASE OBJECT/CLASS;
$dbHelper = new dbHelper($db);
$tableName = "test";
$tableInfo = $dbHelper->extractTableInfo($tableName);
echo json_encode($tableInfo);
To get a list of all tables in a database you'll need:
SHOW TABLES [in dbname]
or follow this question
Still, there are many alternatives with different benefits/outputs:
using mysql workbench
using phpmyadmin
using command line mysqldump -u root -p --no-data dbname > schema.sql