Add Table::columnType() accessor

Since this method is used a few times in the ORM package add a simple
way to read it.

lib/Cake/Database/Schema/Table.php

@@ -209,6 +209,19 @@ public function column($name) {
 		return $this->_columns[$name];
 	}
 
+/**
+ * Convenience method for getting the type of a given column.
+ *
+ * @param string $name The column to get the type of.
+ * @return string|null Either the column type or null.
+ */
+	public function columnType($name) {
+		if (!isset($this->_columns[$name])) {
+			return null;
+		}
+		return $this->_columns[$name]['type'];
+	}
+
 /**
  * Add an index.
  *

lib/Cake/Test/TestCase/Database/Schema/TableTest.php

@@ -64,6 +64,22 @@ public function testAddColumn() {
 		$this->assertEquals(['title', 'body'], $table->columns());
 	}
 
+/**
+ * Test columnType method
+ *
+ * @return void
+ */
+	public function testColumnType() {
+		$table = new Table('articles');
+		$table->addColumn('title', [
+			'type' => 'string',
+			'length' => 25,
+			'null' => false
+		]);
+		$this->assertEquals('string', $table->columnType('title'));
+		$this->assertNull($table->columnType('not there'));
+	}
+
 /**
  * Attribute keys should be filtered and have defaults set.
  *