public T one() {
        this.beforeCheck();

        String sql = this.buildSelectSQL(true);

        T model = this.queryOne(modelClass, sql, paramValues);

        ifThen(null != model && null != joinParams,
                () -> this.setJoin(Collections.singletonList(model)));

        return model;
    }
public T one ( ) { this . beforeCheck ( ) ; String sql = this . buildSelectSQL ( true ) ; T model = this . queryOne ( modelClass , sql , paramValues ) ; ifThen ( null != model && null != joinParams , ( ) -> this . setJoin ( Collections . singletonList ( model ) ) ) ; return model ; }
query and find one model

@return one model