From ab69a8b236986e33d096b13d010981dba58b1958 Mon Sep 17 00:00:00 2001
From: Henrique Pedrosa <henrique@addapp.io>
Date: Sat, 10 Mar 2018 02:36:59 -0300
Subject: [PATCH] Adding fromSub and fromRaw methods to query Builder

---
 src/Illuminate/Database/Query/Builder.php   | 68 +++++++++++++++++----
 tests/Database/DatabaseQueryBuilderTest.php | 34 +++++++++++
 2 files changed, 91 insertions(+), 11 deletions(-)

diff --git a/src/Illuminate/Database/Query/Builder.php b/src/Illuminate/Database/Query/Builder.php
index 3362f025d368..a1c1f0c38f74 100755
--- a/src/Illuminate/Database/Query/Builder.php
+++ b/src/Illuminate/Database/Query/Builder.php
@@ -52,6 +52,7 @@ class Builder
      */
     public $bindings = [
         'select' => [],
+        'from'   => [],
         'join'   => [],
         'where'  => [],
         'having' => [],
@@ -241,15 +242,12 @@ public function selectRaw($expression, array $bindings = [])
     }
 
     /**
-     * Add a subselect expression to the query.
+     * Creates a subquery and parse it.
      *
      * @param  \Closure|\Illuminate\Database\Query\Builder|string $query
-     * @param  string  $as
-     * @return \Illuminate\Database\Query\Builder|static
-     *
-     * @throws \InvalidArgumentException
+     * @return array
      */
-    public function selectSub($query, $as)
+    protected function createSub($query)
     {
         // If the given query is a Closure, we will execute it while passing in a new
         // query instance to the Closure. This will give the developer a chance to
@@ -261,9 +259,23 @@ public function selectSub($query, $as)
         }
 
         // Here, we will parse this query into an SQL string and an array of bindings
-        // so we can add it to the query builder using the selectRaw method so the
-        // query is included in the real SQL generated by this builder instance.
-        list($query, $bindings) = $this->parseSubSelect($query);
+        // so we can later add it to the query builder using a componentRaw method
+        // to include the sub in the real SQL generated by the builder instance.
+        return $this->parseSub($query);
+    }
+
+    /**
+     * Add a subselect expression to the query.
+     *
+     * @param  \Closure|\Illuminate\Database\Query\Builder|string $query
+     * @param  string  $as
+     * @return \Illuminate\Database\Query\Builder|static
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function selectSub($query, $as)
+    {
+        list($query, $bindings) = $this->createSub($query);
 
         return $this->selectRaw(
             '('.$query.') as '.$this->grammar->wrap($as), $bindings
@@ -271,12 +283,46 @@ public function selectSub($query, $as)
     }
 
     /**
-     * Parse the sub-select query into SQL and bindings.
+     * Makes "from" fetch from a subquery.
+     *
+     * @param  \Closure|\Illuminate\Database\Query\Builder|string $query
+     * @param  string  $as
+     * @return \Illuminate\Database\Query\Builder|static
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function fromSub($query, $as)
+    {
+        list($query, $bindings) = $this->createSub($query);
+
+        return $this->fromRaw(
+            '('.$query.') as '.$this->grammar->wrap($as), $bindings
+        );
+    }
+
+    /**
+     * Add a raw or where clause to the query.
+     *
+     * @param  string  $expression
+     * @param  mixed   $bindings
+     * @return \Illuminate\Database\Query\Builder|static
+     */
+    public function fromRaw($expression, $bindings = [])
+    {
+        $this->from = new Expression($expression);
+
+        $this->addBinding($bindings, 'from');
+
+        return $this;
+    }
+
+    /**
+     * Parse the subquery into SQL and bindings.
      *
      * @param  mixed  $query
      * @return array
      */
-    protected function parseSubSelect($query)
+    protected function parseSub($query)
     {
         if ($query instanceof self) {
             return [$query->toSql(), $query->getBindings()];
diff --git a/tests/Database/DatabaseQueryBuilderTest.php b/tests/Database/DatabaseQueryBuilderTest.php
index 6c0fd656d4ae..5f524a88c60c 100755
--- a/tests/Database/DatabaseQueryBuilderTest.php
+++ b/tests/Database/DatabaseQueryBuilderTest.php
@@ -2505,6 +2505,40 @@ public function testWhereRowValuesArityMismatch()
         $builder->select('*')->from('orders')->whereRowValues(['last_update'], '<', [1, 2]);
     }
 
+    public function testFromSub()
+    {
+        $builder = $this->getBuilder();
+        $builder->fromSub(function ($query) {
+            $query->select(new Raw('max(last_seen_at) as last_seen_at'))->from('user_sessions')->where('foo', '=', '1');
+        }, 'sessions')->where('bar', '<', '10');
+        $this->assertEquals('select * from (select max(last_seen_at) as last_seen_at from "user_sessions" where "foo" = ?) as "sessions" where "bar" < ?', $builder->toSql());
+        $this->assertEquals(['1', '10'], $builder->getBindings());
+    }
+
+    public function testFromSubWithoutBindings()
+    {
+        $builder = $this->getBuilder();
+        $builder->fromSub(function ($query) {
+            $query->select(new Raw('max(last_seen_at) as last_seen_at'))->from('user_sessions');
+        }, 'sessions');
+        $this->assertEquals('select * from (select max(last_seen_at) as last_seen_at from "user_sessions") as "sessions"', $builder->toSql());
+    }
+
+    public function testFromRaw()
+    {
+        $builder = $this->getBuilder();
+        $builder->fromRaw(new Raw('(select max(last_seen_at) as last_seen_at from "user_sessions") as "sessions"'));
+        $this->assertEquals('select * from (select max(last_seen_at) as last_seen_at from "user_sessions") as "sessions"', $builder->toSql());
+    }
+
+    public function testFromRawWithWhereOnTheMainQuery()
+    {
+        $builder = $this->getBuilder();
+        $builder->fromRaw(new Raw('(select max(last_seen_at) as last_seen_at from "sessions") as "last_seen_at"'))->where('last_seen_at', '>', '1520652582');
+        $this->assertEquals('select * from (select max(last_seen_at) as last_seen_at from "sessions") as "last_seen_at" where "last_seen_at" > ?', $builder->toSql());
+        $this->assertEquals(['1520652582'], $builder->getBindings());
+    }
+
     protected function getBuilder()
     {
         $grammar = new \Illuminate\Database\Query\Grammars\Grammar;