Unsigned only supported by MySQL.

Signed-off-by: Taylor Otwell <taylorotwell@gmail.com>

laravel/database/schema/grammars/grammar.php

@@ -47,21 +47,6 @@ abstract class Grammar extends \Laravel\Database\Grammar {
 		return "ALTER TABLE ".$this->wrap($table)." DROP CONSTRAINT ".$command->name;
 	}
 
-	/**
-	 * Get the SQL syntax for indicating if a column is unsigned.
-	 *
-	 * @param  Table   $table
-	 * @param  Fluent  $column
-	 * @return string
-	 */
-	protected function unsigned(Table $table, Fluent $column)
-	{
-		if ($column->type == 'integer' && $column->unsigned)
-		{
-			return ' UNSIGNED';
-		}
-	}
-
 	/**
 	 * Wrap a value in keyword identifiers.
 	 *

laravel/database/schema/grammars/mysql.php

@@ -90,6 +90,21 @@ class MySQL extends Grammar {
 		return $columns;
 	}
 
+	/**
+	 * Get the SQL syntax for indicating if a column is unsigned.
+	 *
+	 * @param  Table   $table
+	 * @param  Fluent  $column
+	 * @return string
+	 */
+	protected function unsigned(Table $table, Fluent $column)
+	{
+		if ($column->type == 'integer' && $column->unsigned)
+		{
+			return ' UNSIGNED';
+		}
+	}
+
 	/**
 	 * Get the SQL syntax for indicating if a column is nullable.
 	 *

laravel/database/schema/grammars/postgres.php

@@ -65,7 +65,7 @@ class Postgres extends Grammar {
 			// types to the types used by the database.
 			$sql = $this->wrap($column).' '.$this->type($column);
 
-			$elements = array('unsigned', 'incrementer', 'nullable', 'defaults');
+			$elements = array('incrementer', 'nullable', 'defaults');
 
 			foreach ($elements as $element)
 			{

laravel/database/schema/grammars/sqlite.php

@@ -91,7 +91,7 @@ class SQLite extends Grammar {
 			// types to the types used by the database.
 			$sql = $this->wrap($column).' '.$this->type($column);
 
-			$elements = array('unsigned', 'nullable', 'defaults', 'incrementer');
+			$elements = array('nullable', 'defaults', 'incrementer');
 
 			foreach ($elements as $element)
 			{

laravel/database/schema/grammars/sqlserver.php

@@ -72,7 +72,7 @@ class SQLServer extends Grammar {
 			// types to the types used by the database.
 			$sql = $this->wrap($column).' '.$this->type($column);
 
-			$elements = array('unsigned', 'incrementer', 'nullable', 'defaults');
+			$elements = array('incrementer', 'nullable', 'defaults');
 
 			foreach ($elements as $element)
 			{