compare integer with varchar

There are comparisons between int and varchar in edu.harvard.i2b2.crc/src/server/edu/harvard/i2b2/crc/dao/setfinder/QueryMasterSpringDao.java
This brings error messages in i2b2 with postgresql.
In table i2b2demodata.qt_query_master, column QUERY_MASTER_ID in int but it is compared with master_id which is string.