feat: added ability to select from within a SubQuery or Closure

README.md

@@ -73,12 +73,14 @@ use MgCosta\Spanner\Model\Model;
 
 class User extends Model {
 
-    protected $primaryKey = 'UserId';
+    protected $primaryKey = 'userId';
 
     // available strategies [uuid4, increment] 
     // increment is not recommend by cloud spanner
     protected $keyStrategy = 'uuid4';
 
+    // we must define the properties which corresponds to the columns of the table as public
+    public $userId;
     public $name;
     public $age;
     public $email;

src/Spanner/Builder/Builder.php

@@ -173,12 +173,30 @@ public function getModel(): Model
         return $this->model;
     }
 
-    public function from(string $table, string $as = null): self
+    public function from($table, string $as = null): self
     {
+        if ($this->isQueryable($table)) {
+            return $this->fromSub($table, $as);
+        }
+
         $this->from = $as ? "{$table} as {$as}" : $table;
         return $this;
     }
 
+    public function fromSub($query, $as): self
+    {
+        [$query, $bindings] = $this->createSub($query);
+        return $this->fromRaw('(' . $query . ') as ' . $this->grammar->wrapTable($as), $bindings);
+    }
+
+    public function fromRaw($expression, $bindings = []): self
+    {
+        $this->from = new Expression($expression);
+
+        $this->addBinding($bindings, 'from');
+        return $this;
+    }
+
     public function join($table, $first, $operator = null, $second = null, $type = 'inner', $where = false): self
     {
         $join = $this->newJoinClause($this, $type, $table);

src/Spanner/Builder/Grammar/SpannerGrammar.php

@@ -316,7 +316,7 @@ protected function concatenate($segments): string
         }));
     }
 
-    protected function wrapTable($table)
+    public function wrapTable($table)
     {
         if (! $this->isExpression($table)) {
             return $this->wrap($this->tablePrefix . $table, true);
@@ -325,7 +325,7 @@ protected function wrapTable($table)
         return $table->getValue($table);
     }
 
-    private function wrap($value, $prefixAlias = false)
+    protected function wrap($value, $prefixAlias = false)
     {
         if ($this->isExpression($value)) {
             return $value->getValue($value);
@@ -339,7 +339,7 @@ private function wrap($value, $prefixAlias = false)
         return $this->wrapSegments(explode('.', $value));
     }
 
-    private function wrapAliasedValue($value, $prefixAlias = false): string
+    protected function wrapAliasedValue($value, $prefixAlias = false): string
     {
         $segments = preg_split('/\s+as\s+/i', $value);
 
@@ -350,7 +350,7 @@ private function wrapAliasedValue($value, $prefixAlias = false): string
         return $this->wrap($segments[0]) . ' as ' . $this->wrapValue($segments[1]);
     }
 
-    private function wrapValue($value): string
+    protected function wrapValue($value): string
     {
         if ($value !== '*') {
             return str_replace('"', '""', $value);
@@ -359,12 +359,7 @@ private function wrapValue($value): string
         return $value;
     }
 
-    private function isExpression($value): bool
-    {
-        return $value instanceof Expression;
-    }
-
-    private function wrapSegments($segments): string
+    protected function wrapSegments($segments): string
     {
         return collect($segments)->map(function ($segment, $key) use ($segments) {
             return $key == 0 && count($segments) > 1
@@ -373,6 +368,11 @@ private function wrapSegments($segments): string
         })->implode('.');
     }
 
+    private function isExpression($value): bool
+    {
+        return $value instanceof Expression;
+    }
+
     private function columnize(array $columns): string
     {
         return implode(', ', array_map([$this, 'wrap'], $columns));

src/Spanner/Builder/Interfaces/Operator.php

@@ -7,6 +7,10 @@
 
 interface Operator
 {
+    public function from($table, string $as = null): Builder;
+    public function fromSub($query, $as): Builder;
+    public function fromRaw($expression, $bindings = []): Builder;
+
     public function select($columns = ['*']): Builder;
     public function selectSub($query, $as): Builder;
     public function selectRaw($expression, array $bindings = []): Builder;

src/Spanner/Facade/SpannerDB.php

@@ -22,8 +22,8 @@ public function __construct(Database $connection = null)
         $this->connection = $connection ?? Manager::getConnection();
     }
 
-    public function table(string $name): Builder
+    public function table($name, $as = null): Builder
     {
-        return (new Builder($this->connection))->from($name);
+        return (new Builder($this->connection))->from($name, $as);
     }
 }

tests/unit/BuilderTest.php

@@ -46,6 +46,15 @@ public function testShouldAssignFromAndModelWhenCallingSetModelProperly()
         $this->assertEquals('dummymodel', $this->builder->from);
     }
 
+    public function testShouldAssignProperBindingsWhenCallingFromWithSubQuery()
+    {
+        $subQuery = new Builder(m::mock(Database::class));
+        $subQuery->from('persons')->where('age', '>=', 35);
+        $this->builder->from($subQuery, 'table');
+
+        $this->assertEquals(['param1' => 35], $this->builder->bindings['from']);
+        $this->assertEquals('(select * from persons where age >= @param1) as table', $this->builder->from);
+    }
 
     public function testShouldThrowAnInvalidArgumentExceptionModelWhenCallingAddBindingWithInvalidType()
     {