LazyRecord\SqlBuilder\SqliteBuilder::buildColumnSql PHP Method

    public function buildColumnSql(SchemaInterface $schema, DeclareColumn $column)
    {
        $name = $column->name;
        $isa = $column->isa ?: 'str';
        $type = $column->type;
        if (!$type && $isa == 'str') {
            $type = 'text';
        }
        // Note that sqlite doesn't support unsigned integer primary key column
        if ($column->autoIncrement) {
            $column->unsigned = false;
        }
        $args = new ArgumentArray();
        $sql = $column->buildDefinitionSql($this->driver, $args);
        /*
         * build sqlite reference
         *    create table track(
         *        trackartist INTEGER,
         *        FOREIGN KEY(trackartist) REFERENCES artist(artistid)
         *    )
         * @see http://www.sqlite.org/foreignkeys.html
         *
         * CREATE TABLE album(
         *     albumartist TEXT,
         *     albumname TEXT,
         *     albumcover BINARY,
         *     PRIMARY KEY(albumartist, albumname)
         *     );
         *
         * CREATE TABLE song(
         *     songid     INTEGER,
         *     songartist TEXT,
         *     songalbum TEXT,
         *     songname   TEXT,
         *     FOREIGN KEY(songartist, songalbum) REFERENCES album(albumartist, albumname)
         * );
         */
        foreach ($schema->relations as $rel) {
            switch ($rel['type']) {
                case Relationship::BELONGS_TO:
                case Relationship::HAS_MANY:
                case Relationship::HAS_ONE:
                    if ($name != 'id' && $rel['self_column'] == $name) {
                        $fSchema = new $rel['foreign_schema']();
                        $fColumn = $rel['foreign_column'];
                        $sql .= ' REFERENCES ' . $fSchema->getTable() . '(' . $fColumn . ')';
                    }
                    break;
            }
        }
        return $sql;
    }