mysqlでグループごとの最新の日付を持つ一覧表示

mysql

2021.09.14 2020.07.25

mysqlでグループごとの最新の日付の一覧を取得したい場合

SELECT * FROM 

  tb_m_contact1 as con1
	left JOIN tb_m_anken ON con1.contact1_a_id =  tb_m_anken.anken_id 
	left JOIN pl_su1 ON con1.contact1_c_id =  pl_su1.su1_id 

WHERE `contact1_update1`=(SELECT MAX(`contact1_update1`)
    FROM tb_m_contact1 WHERE contact1_remarks3=con1.contact1_remarks3)
    and (contact1_u_id = '181961' or contact1_c_id = '181961' or contact1_remarks2 = '181961' or contact1_flg_id='181961')

mysql — 最大日付を持つGROUP BY

このコードを実行すると問題が発生します。SELECT * FROM tblpm n WHERE date_updated=(SELECT MAX(date_updated) FROM tblpm GROUP BY control_number HAVING control_number=n.control_number...

その２

SELECT

staff_aid,
staff_id,
CONVERT( AES_DECRYPT( UNHEX(staff_name1),'$this->vkey1') USING utf8 ) as staff_name1,
chat1.chat1_u_id as chat1_u_id,
CONVERT( AES_DECRYPT( UNHEX(chat1.chat1_u_name),'$this->vkey1') USING utf8 ) as chat1_u_name,
chat1.chat1_datetime,
CONVERT( AES_DECRYPT( UNHEX(chat1.chat1_su_name),'$this->vkey1') USING utf8 ) as chat1_su_name,
CONVERT( AES_DECRYPT( UNHEX(chat1.chat1_message),'$this->vkey1') USING utf8 ) as chat1_message


FROM
co_staff
LEFT JOIN  pl_su_chat1 as aa ON
co_staff.staff_id = aa.chat1_u_id
LEFT JOIN	pl_su_chat1 AS chat1 ON
co_staff.staff_id = chat1.chat1_u_id
LEFT JOIN
         pl_su_chat1 AS chat2 ON (chat1.chat1_u_id = chat2.chat1_u_id AND chat1.chat1_datetime < chat2.chat1_datetime)
         WHERE
             chat2.chat1_datetime IS NULL