#3 Change data types for tbl_jobListing table

[Sangeun Ju]

Change data type from varchar(15) to "int" for
salaryRange, HourType, JobCatagory, JobType columns
of tbl_jobListing table to create relationships with
tbl_salaryRange, tbl_hourstype, tbl_jobCatagory, and
tbl_jobType.