Malawi-Stock-Exchange-API/app/Core/QueryBuilder.php

<?php 
namespace App\Core;

use PDO;

class QueryBuilder {
    protected $pdo;
    protected $table;
    protected $where = [];
    protected $params = [];
    protected $orderBy = [];
    protected $limit = null;
    protected $selects = '*'; // Defaults to everything
    protected $joins = [];

    public function __construct(PDO $pdo) {
        $this->pdo = $pdo;
    }

    public function table($table) {
        $this->table = $table;
        return $this;
    }

    // Notice the new $boolean parameter (defaults to 'AND')
    public function where($column, $operator, $value = null, $boolean = 'AND') {
        if ($value === null) {
            $value = $operator;
            $operator = '=';
        }

        $paramName = 'where_' . str_replace('.', '_', $column) . '_' . count($this->params);

        // If this is the first where clause, we don't need 'AND' or 'OR'
        $prefix = empty($this->where) ? '' : strtoupper($boolean) . ' ';

        $this->where[] = "{$prefix}{$column} {$operator} :{$paramName}";
        $this->params[$paramName] = $value;

        return $this;
    }

    // orWhere simply calls where() but passes 'OR'
    public function orWhere($column, $operator, $value = null) {
        return $this->where($column, $operator, $value, 'OR');
    }

    // Sort the results
    public function orderBy($column, $direction = 'ASC') {
        $direction = strtoupper($direction) === 'DESC' ? 'DESC' : 'ASC';
        $this->orderBy[] = "{$column} {$direction}";
        return $this;
    }

    // Limit the number of results
    public function limit(int $limit) {
        $this->limit = $limit;
        return $this;
    }

    // Fetch a single record instead of an array of arrays
    public function first() {
        $this->limit(1);
        $result = $this->get();
        return $result ? $result[0] : null;
    }

    public function getOld() {
        $sql = "SELECT * FROM {$this->table}";
        
        // Changed implode from ' AND ' to ' ' because the prefix handles it now
        if (!empty($this->where)) {
            $sql .= " WHERE " . implode(' ', $this->where);
        }

        if (!empty($this->orderBy)) {
            $sql .= " ORDER BY " . implode(', ', $this->orderBy);
        }

        if ($this->limit !== null) {
            $sql .= " LIMIT {$this->limit}";
        }

        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($this->params);
        return $stmt->fetchAll();
    }
    public function get() {
        // Use the new selects property instead of hardcoded '*'
        $sql = "SELECT {$this->selects} FROM {$this->table}";
        
        // Add joins immediately after the FROM clause
        if (!empty($this->joins)) {
            $sql .= " " . implode(' ', $this->joins);
        }

        if (!empty($this->where)) {
            $sql .= " WHERE " . implode(' ', $this->where);
        }

        if (!empty($this->orderBy)) {
            $sql .= " ORDER BY " . implode(', ', $this->orderBy);
        }

        if ($this->limit !== null) {
            $sql .= " LIMIT {$this->limit}";
        }

        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($this->params);
        return $stmt->fetchAll();
    }

    public function insert(array $data) {
        $columns = implode(', ', array_keys($data));
        $placeholders = ':' . implode(', :', array_keys($data));

        $sql = "INSERT INTO {$this->table} ({$columns}) VALUES ({$placeholders})";
        return $this->pdo->prepare($sql)->execute($data);
    }

    public function update(array $data) {
        $fields = "";
        foreach ($data as $key => $value) {
            $fields .= "{$key} = :{$key}, ";
        }
        $fields = rtrim($fields, ', ');

        $sql = "UPDATE {$this->table} SET {$fields}";
        if (!empty($this->where)) {
            $sql .= " WHERE " . implode(' ', $this->where);
        }

        return $this->pdo->prepare($sql)->execute(array_merge($data, $this->params));
    }

    public function delete() {
        $sql = "DELETE FROM {$this->table}";
        if (!empty($this->where)) {
            $sql .= " WHERE " . implode(' ', $this->where);
        }

        return $this->pdo->prepare($sql)->execute($this->params);
    }
    // Specify exactly which columns to return
    public function select($columns) {
        // Allow passing an array ['id', 'name'] or a raw string 'id, name'
        $this->selects = is_array($columns) ? implode(', ', $columns) : $columns;
        return $this;
    }

    // The main join method
    public function join($table, $firstColumn, $operator, $secondColumn, $type = 'INNER') {
        $this->joins[] = "{$type} JOIN {$table} ON {$firstColumn} {$operator} {$secondColumn}";
        return $this;
    }

    // A helpful shortcut for LEFT JOINS
    public function leftJoin($table, $firstColumn, $operator, $secondColumn) {
        return $this->join($table, $firstColumn, $operator, $secondColumn, 'LEFT');
    }
}
?>