SELECT
IM.PORT_CODE 港コード,
PORT_NAME 港名,
SUM(IM.AMT) 入国者数,
SUM(IMM.AMT) 出国者数,
SUM(IM.AMT)-SUM(IMM.AMT) 差分
FROM IMMIGRATION as IM
LEFT JOIN GRP ON IM.GROUP_CODE=GRP.GROUP_CODE
LEFT JOIN PORT ON IM.PORT_CODE=PORT.PORT_CODE
INNER JOIN IMMIGRATION as IMM ON IM.PORT_CODE=IMM.PORT_CODE
and IMM.KIND_CODE=120
and IMM.GROUP_CODE=120
WHERE IM.KIND_CODE =110 and IM.GROUP_CODE=120
GROUP by 港名,IM.KIND_CODE,IM.GROUP_CODE
HAVING SUM(IM.AMT)>SUM(IMM.AMT)
ORDER by 差分 DESC,港コード DESC