Using column alias in Mybatis3 Dynamic SQL

Question

i am using Mybatis3 dynamic SQL to implement the following SQL:

select count(column1) from table1 left join (
select column11, column22, column1 from table2
where tag='OK'
) subquery
on table1.column1 = subquery.column1

it is actually to count all the items for paging. Here is the mybatis3 dynamic sql code:

        SqlBuilder.countColumn(table1.column1)
          .from(table1)
          .leftjoin(
            SqlBuilder.select(
              table2.column11,
              table2.column22,
              table2.column1
            )from(table2).where(table2.tag, isEqualTo("OK")),
            "subquery",
            on(table1.column1, equalTo(table2.column1.qualifiedWith("subquery"))),
            new ArrayList()
          );

The problem is the on clause, it says ambiguous column1. However, the FromGatherer of SqlBuilder.countColumn is quite different from SqlBuilder.select. org.mybatis.dynamic.sql.select.CountDSL.FromGatherer#from does not accept table alias as org.mybatis.dynamic.sql.select.QueryExpressionDSL.FromGatherer#from does.

I have build a similar Query statement and that works well on the "on clause" with table alias and subquery alias

i also tried column alias:

        SqlBuilder.countColumn(table1.column1)
          .from(table1)
          .leftjoin(
            SqlBuilder.select(
              table2.column11,
              table2.column22,
              table2.column1.as("new_column1")
            )from(table2).where(table2.tag, isEqualTo("OK")),
            "subquery",
            on(table1.column1, equalTo(table2.column1.as("new_column1"))),
            new ArrayList()
          );

however in the output statement, the column alias does not render in the "on clause"

any suggestions on how to solve this ambiguity of count statement?

if the column alias in subquery can work in the "on clause", i think it would solve the problem.