public NumberExpression<Integer> yearMonth() {
        if (yearMonth == null) {
            yearMonth = Expressions.numberOperation(Integer.class, Ops.DateTimeOps.YEAR_MONTH, mixin);
        }
        return yearMonth;
    }
Create a year / month expression

@return year month
querydsl-core/src/main/java/com/querydsl/core/types/dsl/DateExpression.java