feat: add query builder

composer.json

@@ -3,7 +3,8 @@
         "files": [ "src/classnames/function.php" ],
         "psr-4": {
             "ClassNames\\": "src/classnames",
-            "MergeCoverage\\": "src/merge-coverage"
+            "MergeCoverage\\": "src/merge-coverage",
+            "QueryBuilder\\": "src/query-builder"
         }
     },
     "require-dev": {

phpunit.xml

@@ -13,6 +13,9 @@
         <testsuite name="classnames">
             <directory>src/classnames/Tests</directory>
         </testsuite>
+        <testsuite name="query-builder">
+            <directory>src/query-builder/Tests</directory>
+        </testsuite>
     </testsuites>
 
     <source restrictDeprecations="true" restrictNotices="true" restrictWarnings="true">

src/query-builder/Column.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace QueryBuilder;
+
+class Column
+{
+    public function __construct(
+        private string $expression,
+        private ?string $alias = null
+    ) {
+    }
+
+    public function __toString()
+    {
+        if ($this->alias) {
+            return $this->expression . ' AS ' . $this->alias;
+        }
+        return $this->expression;
+    }
+}

src/query-builder/From.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace QueryBuilder;
+
+use QueryBuilder\Join\Equals;
+
+class From
+{
+    public function __construct(private string $expression)
+    {
+    }
+
+    public function join(string $table, Equals $condition )
+    {
+        $this->expression .= PHP_EOL . Query::INDENT . 'JOIN ' . $table . ' ON ' . (string) $condition;
+    }
+
+    public function __toString()
+    {
+        return 'FROM ' . $this->expression;
+    }
+}

src/query-builder/Join.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace QueryBuilder;
+
+class Join
+{
+    public function __construct(private string $table)
+    {
+        $this->table = $table;
+    }
+
+    private function plop($from, $join) {
+
+    }
+
+    public function __toString()
+    {
+        return Query::INDENT . "JOIN " . $this->table . $this->conditions();
+    }
+}

src/query-builder/Join/Equals.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace QueryBuilder\Join;
+
+use QueryBuilder\Column;
+
+class Equals
+{
+    public function __construct(private Column $left, private Column $right)
+    {
+    }
+
+    public function __toString()
+    {
+        return $this->left . ' = ' . $this->right;
+    }
+}

src/query-builder/Query.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace QueryBuilder;
+
+class Query
+{
+    const INDENT = "    ";
+
+    const FINAL_SEMI_COLON = ";" . PHP_EOL;
+
+    private $select;
+    private $from;
+    private $where;
+
+    public function __construct(Select $select, From $from, Where $where)
+    {
+        $this->select = $select;
+        $this->from   = $from;
+        $this->where  = $where;
+    }
+
+    public function __toString()
+    {
+        $parts = [
+            $this->select,
+            $this->from,
+            "WHERE " . $this->where,
+            Query::FINAL_SEMI_COLON,
+        ];
+
+        return implode(PHP_EOL, $parts);
+    }
+}
+

src/query-builder/Select.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace QueryBuilder;
+
+class Select
+{
+    private array $columns;
+
+    public function __construct(Column ...$columns)
+    {
+        $this->columns = $columns;
+    }
+
+    public function add(Column $column){
+        $this->columns[] = $column;
+        return $this;
+    }
+
+    public function __toString()
+    {
+        $select = implode("," . PHP_EOL . Query::INDENT, $this->columns);
+        return "SELECT" . PHP_EOL . Query::INDENT . $select;
+    }
+}

src/query-builder/Sum.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace QueryBuilder;
+
+class Sum extends Column
+{
+    public function __construct(
+        private string $expression,
+        private ?string $alias = null
+    ) {
+        $this->expression = 'SUM(' . $this->expression . ')';
+    }
+
+    public function __toString()
+    {
+        if ($this->alias) {
+            return $this->expression . ' AS ' . $this->alias;
+        }
+        return $this->expression;
+    }
+}

src/query-builder/Table.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace QueryBuilder;
+
+class Table
+{
+    public function __construct(protected string $name, private ?string $alias = null)
+    {
+    }
+
+    public function from() {
+        return new From($this->alias ? $this->name . ' ' . $this->alias : $this->name);
+    }
+
+    public function column(string $expression, ?string $alias = null)
+    {
+        $table = $this->alias ?? $this->name;
+        return new Column($table . '.' . $expression, $alias);
+    }
+
+    public function sum(string $expression, ?string $as = null)
+    {
+        $table = $this->alias ?? $this->name;
+        return new Sum($table . '.' . $expression, $as);
+    }
+
+    public function __toString()
+    {
+        return $this->alias ?? $this->name;
+    }
+}

src/query-builder/Tests/QueryTest.php

@@ -0,0 +1,91 @@
+<?php
+declare(strict_types=1);
+
+namespace QueryBuilder\Tests;
+
+use PHPUnit\Framework\TestCase;
+use QueryBuilder\From;
+use QueryBuilder\Join\Equals;
+use QueryBuilder\Query;
+use QueryBuilder\Select;
+use QueryBuilder\Table;
+use QueryBuilder\Where;
+
+class QueryTest extends TestCase
+{
+    public function testQuery()
+    {
+        $customers = new class('customers') extends Table {
+            public function name() {
+                return $this->column('name');
+            }
+            public function id() {
+                return $this->column('id');
+            }
+            public function departement() {
+                return $this->column('departement');
+            }
+            public function departementShouldBe(int $departement) {
+                return new Where\Equals($this->departement(), (string) $departement);
+            }
+
+            public function joins(Table $orders){
+                return $orders->from()->join($this->name, new Equals($orders->customerId(), $this->id()));
+            }
+        };
+
+        $orders = new class('orders') extends Table {
+            public function customerId() {
+                return $this->column('customer_id');
+            }
+            public function id() {
+                return $this->column('id');
+            }
+            public function valid() {
+                return $this->column('valid');
+            }
+            public function shouldBeValid() {
+                return new Where\Equals($this->column('valid'), 'TRUE');
+            }
+            public function total() {
+                return $this->sum('price',as: 'total');
+            }
+        };
+
+        $customerOrders = new class($orders, $customers) extends From {
+            public function __construct($orders, $customers)
+            {
+                parent::__construct('orders');
+                $this->join('customers', new Equals($orders->customerId(), $customers->id()));
+            }
+        };
+
+        $select = new Select(
+            $orders->total(),
+            $customers->name(),
+        );
+
+        $validDepartements = Where::atLeastOne(
+            $customers->departementShouldBe(14),
+            $customers->departementShouldBe(15),
+        );
+        $where = Where::everyOnes(
+            $orders->shouldBeValid(),
+            $validDepartements,
+        );
+
+        $query = new Query($select, $customerOrders, $where);
+
+        $sql = <<<SQL
+SELECT
+    SUM(orders.price) AS total,
+    customers.name
+FROM orders
+    JOIN customers ON orders.customer_id = customers.id
+WHERE orders.valid = TRUE AND (customers.departement = 14 OR customers.departement = 15)
+;
+
+SQL;
+         self::assertSame($sql, (string) $query);
+    }
+}

src/query-builder/Where.php

@@ -0,0 +1,36 @@
+<?php
+
+
+namespace QueryBuilder;
+
+use QueryBuilder\Where\Ensemble;
+
+class Where
+{
+    public function __construct(private string $expression)
+    {
+    }
+
+    public static function atLeastOne(self ...$wheres): self {
+        foreach ($wheres as &$where) {
+            if ($where instanceof Ensemble) {
+                $where = '(' . $where . ')';
+            }
+        }
+        return new Ensemble(implode(' OR ', $wheres));
+    }
+
+    public static function everyOnes(self ...$wheres): self {
+        foreach ($wheres as &$where) {
+            if ($where instanceof Ensemble) {
+                $where = '(' . $where . ')';
+            }
+        }
+        return new Ensemble(implode(' AND ', $wheres));
+    }
+
+    public function __toString(): string
+    {
+        return $this->expression;
+    }
+}

src/query-builder/Where/Ensemble.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace QueryBuilder\Where;
+
+use QueryBuilder\Column;
+use QueryBuilder\Where;
+
+class Ensemble extends Where
+{
+    public function __construct(private string $expression)
+    {
+    }
+
+    public function __toString(): string
+    {
+        return $this->expression;
+    }
+}
+

src/query-builder/Where/Equals.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace QueryBuilder\Where;
+
+use QueryBuilder\Column;
+use QueryBuilder\Where;
+
+class Equals extends Where
+{
+    public function __construct(private Column $left, private string $right)
+    {
+    }
+
+    public function __toString(): string
+    {
+        return $this->left . ' = ' . $this->right;
+    }
+}
+