Added function expression

Author: Daniel Opitz

src/Database/FunctionBuilder.php

@@ -31,94 +31,88 @@ public function __construct(Connection $db)
      *
      * @param string $field Field name
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function sum(string $field): RawExp
+    public function sum(string $field): FunctionExpression
     {
-        $expression = sprintf('SUM(%s)', $this->db->getQuoter()->quoteName($field));
+        $quoter = $this->db->getQuoter();
+        $expression = sprintf('SUM(%s)', $quoter->quoteName($field));
 
-        return new RawExp($expression);
+        return new FunctionExpression($expression, $quoter);
     }
 
     /**
      * Calculate an average. The arguments will be treated as literal values.
      *
      * @param string $field Field name
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function avg(string $field): RawExp
+    public function avg(string $field): FunctionExpression
     {
-        $expression = sprintf('AVG(%s)', $this->db->getQuoter()->quoteName($field));
+        $quoter = $this->db->getQuoter();
+        $expression = sprintf('AVG(%s)', $quoter->quoteName($field));
 
-        return new RawExp($expression);
+        return new FunctionExpression($expression, $quoter);
     }
 
     /**
      * Calculate the min of a column. The arguments will be treated as literal values.
      *
      * @param string $field Field name
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function min(string $field): RawExp
+    public function min(string $field): FunctionExpression
     {
-        $expression = sprintf('MIN(%s)', $this->db->getQuoter()->quoteName($field));
+        $quoter = $this->db->getQuoter();
+        $expression = sprintf('MIN(%s)', $quoter->quoteName($field));
 
-        return new RawExp($expression);
+        return new FunctionExpression($expression, $quoter);
     }
 
     /**
      * Calculate the max of a column. The arguments will be treated as literal values.
      *
      * @param string $field Field name
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function max(string $field): RawExp
+    public function max(string $field): FunctionExpression
     {
-        $expression = sprintf('MAX(%s)', $this->db->getQuoter()->quoteName($field));
+        $quoter = $this->db->getQuoter();
+        $expression = sprintf('MAX(%s)', $quoter->quoteName($field));
 
-        return new RawExp($expression);
+        return new FunctionExpression($expression, $quoter);
     }
 
     /**
      * Calculate the count. The arguments will be treated as literal values.
      *
      * @param string $field Field name (Default is *)
+     * @param string|null $alias Alias
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function count(string $field = '*'): RawExp
+    public function count(string $field = '*', string $alias = null): RawExp
     {
-        $expression = sprintf('COUNT(%s)', $this->db->getQuoter()->quoteName($field));
+        $quoter = $this->db->getQuoter();
+        $expression = sprintf('COUNT(%s)', $quoter->quoteName($field));
 
-        return new RawExp($expression);
-    }
-
-    /**
-     * Calculate the count. The arguments will be treated as literal values.
-     *
-     * @param string $field Field name (Default is *)
-     * @param string ...$fields Field names
-     *
-     * @return RawExp Expression
-     */
-    public function concat(string $field, string ...$fields): RawExp
-    {
-        $names = $this->db->getQuoter()->quoteNames(array_merge([$field], $fields));
-        $expression = sprintf('CONCAT(%s)', implode(', ', $names));
+        if ($alias !== null) {
+            $expression .= sprintf(' %s AS %s', $expression, $quoter->quoteName($alias));
+        }
 
-        return new RawExp($expression);
+        return new FunctionExpression($expression, $quoter);
     }
 
     /**
      * Returns a Expression representing a call that will return the current date and time (ISO).
      *
-     * @return RawExp Expression
+     * @return FunctionExpression Expression
      */
-    public function now(): RawExp
+    public function now(): FunctionExpression
     {
-        return new RawExp('NOW()');
+        return new FunctionExpression('NOW()', $this->db->getQuoter());
     }
 }

src/Database/FunctionExpression.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace Odan\Database;
+
+/**
+ * Contains methods related to generating Expression objects
+ * with most commonly used SQL functions.
+ * This acts as a factory for RawExp objects.
+ */
+class FunctionExpression extends RawExp
+{
+    /**
+     * @var Quoter
+     */
+    protected $quoter;
+
+    /**
+     * Constructor.
+     *
+     * @param string $value
+     * @param Quoter $quoter
+     */
+    public function __construct(string $value, Quoter $quoter)
+    {
+        parent::__construct($value);
+        $this->quoter = $quoter;
+    }
+
+    /**
+     * Alias.
+     *
+     * @param string|null $alias Alias
+     *
+     * @return $this
+     */
+    public function alias(string $alias = null)
+    {
+        $clone = clone $this;
+        $clone->value = sprintf('%s AS %s', $clone->value, $this->quoter->quoteName($alias));
+
+        return $clone;
+    }
+}

src/Database/RawExp.php

@@ -2,20 +2,41 @@
 
 namespace Odan\Database;
 
+/**
+ * Raw Expression.
+ */
 class RawExp
 {
+    /**
+     * @var string
+     */
     protected $value;
 
-    public function __construct($value)
+    /**
+     * Constructor.
+     *
+     * @param string $value
+     */
+    public function __construct(string $value)
     {
         $this->value = $value;
     }
 
+    /**
+     * To string.
+     *
+     * @return string
+     */
     public function __toString()
     {
         return $this->getValue();
     }
 
+    /**
+     * Get value.
+     *
+     * @return string
+     */
     public function getValue()
     {
         return $this->value;

tests/FunctionBuilderTest.php

@@ -5,6 +5,7 @@
 namespace Odan\Database\Test;
 
 use Odan\Database\FunctionBuilder;
+use Odan\Database\RawExp;
 
 /**
  * @coversDefaultClass \Odan\Database\FunctionBuilder
@@ -33,6 +34,10 @@ public function testSum()
 
         $this->assertEquals('SUM(`field`)', $func->sum('field'));
         $this->assertEquals('SUM(`table`.`field`)', $func->sum('table.field'));
+
+        $query = $this->getConnection()->select()->from('payments');
+        $query->columns($query->func()->count('amount'));
+        $this->assertEquals('SELECT COUNT(`amount`) FROM `payments`;', $query->build());
     }
 
     /**
@@ -85,19 +90,10 @@ public function testCount()
 
         $this->assertEquals('COUNT(*)', $func->count());
         $this->assertEquals('COUNT(`field`)', $func->count('field'));
-    }
-
-    /**
-     * Test.
-     *
-     * @return void
-     */
-    public function testConcat()
-    {
-        $func = $this->getConnection()->select()->func();
 
-        $this->assertEquals('CONCAT(`field`)', $func->concat('field'));
-        $this->assertEquals('CONCAT(`field`, `field2`, `field3`)', $func->concat('field', 'field2', 'field3'));
+        $query = $this->getConnection()->select()->from('users');
+        $query->columns($query->func()->count());
+        $this->assertEquals('SELECT COUNT(*) FROM `users`;', $query->build());
     }
 
     /**
@@ -109,6 +105,8 @@ public function testNow()
     {
         $func = $this->getConnection()->select()->func();
 
+        $this->assertInstanceOf(RawExp::class, $func->now());
         $this->assertEquals('NOW()', $func->now());
+        $this->assertEquals('NOW() AS `alias_field`', $func->now()->alias('alias_field')->getValue());
     }
 }