with D_IMM as (
SELECT  PORT_CODE
       ,AMT
FROM    IMMIGRATION
WHERE KIND_CODE  = '110'
AND   GROUP_CODE = '120'
),
E_IMM as (
SELECT  PORT_CODE
       ,AMT
FROM    IMMIGRATION
WHERE KIND_CODE  = '120'
AND   GROUP_CODE = '120'
)
SELECT  D_IMM.PORT_CODE       AS '港コード'
       ,PORT.PORT_NAME        AS '港名'
       ,D_IMM.AMT             AS '入国者数'
       ,E_IMM.AMT             AS '出国者数'
       ,D_IMM.AMT - E_IMM.AMT AS '差分'
FROM    D_IMM
       ,E_IMM
       ,PORT
WHERE D_IMM.PORT_CODE  = E_IMM.PORT_CODE
AND   D_IMM.PORT_CODE  = PORT.PORT_CODE
ORDER BY 5 desc,1 desc;