Introduce truncate method

Author: dpanta94

src/Schema/Tables/Contracts/Table.php

@@ -220,6 +220,28 @@ public function empty_table() {
 
 		$this_table = static::table_name( true );
 
+		$this->db::query( "SET foreign_key_checks = 0" );
+		$result = $this->db::query( "DELETE FROM {$this_table}" );
+		$this->db::query( "SET foreign_key_checks = 1" );
+
+		return $result;
+	}
+
+	/**
+	 * Truncates the custom table.
+	 *
+	 * @since TBD
+	 *
+	 * @return int|false The number of removed rows, or `false` to indicate a failure.
+	 */
+	public function truncate() {
+		if ( ! $this->exists() ) {
+			// There is really nothing to empty here.
+			return 0;
+		}
+
+		$this_table = static::table_name( true );
+
 		$this->db::query( "SET foreign_key_checks = 0" );
 		$result = $this->db::query( "TRUNCATE {$this_table}" );
 		$this->db::query( "SET foreign_key_checks = 1" );