Added fluent interface

Author: jkapuscik2

structural/FluentInterface/QueryBuilder.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Structural\FluentInterface;
+
+class QueryBuilder
+{
+
+    private string $query = "";
+
+    public function select(array $fields = []): QueryBuilder
+    {
+        $this->query .= sprintf("SELECT %s ", sizeof($fields) ? implode(", ", $fields) : "*");
+
+        return $this;
+    }
+
+    public function from(string $tableName): QueryBuilder
+    {
+        $this->query .= " FROM {$tableName} ";
+
+        return $this;
+    }
+
+    public function where(array $conditions): QueryBuilder
+    {
+        $this->query .= sprintf("WHERE %s ", implode(" AND ", $conditions));
+
+        return $this;
+    }
+
+    public function offset(int $offset): QueryBuilder
+    {
+        $this->query .= "OFFSET {$offset} ";
+
+        return $this;
+    }
+
+    public function limit(int $limit): QueryBuilder
+    {
+        $this->query .= "LIMIT {$limit} ";
+
+        return $this;
+    }
+
+    public function orderBy(string $orderRule): QueryBuilder
+    {
+        $this->query .= "ORDER BY {$orderRule} ";
+
+        return $this;
+    }
+
+    public function getQuery() : string
+    {
+        return $this->query;
+    }
+}

structural/FluentInterface/demo.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Structural\FluentInterface;
+
+require(__DIR__ . '/../../vendor/autoload.php');
+
+echo (new QueryBuilder())
+    ->select(["name", "surname"])
+    ->from("users")
+    ->where(["name = 'John'", "city = 'Warsaw'"])
+    ->orderBy("date ASC")
+    ->limit(10)
+    ->getQuery();
+