SELECT DISTINCT PF.PF_CODE AS '都道府県コード', PF.PF_NAME AS '都道府県名',
(SELECT PT.TOTAL_AMT FROM POPU_TRANSITION AS PT WHERE PT.SURVEY_YEAR = 2015) AS '総人口2015年',
(SELECT PT.TOTAL_AMT FROM POPU_TRANSITION AS PT WHERE PT.SURVEY_YEAR = 2020) AS '総人口2020年'
FROM POPU_TRANSITION AS PT
INNER JOIN PREFECTURE AS PF
ON PT.PF_CODE = PF.PF_CODE;