select * from openquery(ERSCACP, 'select LTRIM(a.CUST_CNT_NAME) as A1, LTRIM(a.LOCATION_CODE) as A2, LTRIM(a.ACCT_NUM) as A3, LTRIM(b.SSN_NUM) as A4 from CACSUSR.P340PHN a, CACSUSR.P340SSN b WHERE a.PHONE_NUM = ''szInputCellphone'' and a.LOCATION_CODE = b.LOCATION_CODE and a.ACCT_NUM = b.ACCT_NUM')
여기서 b.ssn_num 컬럼이 13자리인것만 추출하고 싶은데.. 어떤식으로 추출해야될지 고민됩니다 ㅠㅠ