MySQL - 查询未读消息和邮件消息

Question

我需要在一个查询中检索带有用户名和未读消息计数的消息。正在使用的查询是下面的查询，并检索用户的名称以及剩余的内容以获取未读消息的计数。如何从 EMAIL_MESSAGE (MESSAGE_STATUS='U') 获取未读消息到此查询，以便我将信息与其他详细信息一起获取。

SELECT e.MAIL_NO, e.BIZ_ID, e.FROM_ADD, e.TO_ADD, e.EMAIL_SUBJECT,  
      DATE_FORMAT(e.UPDATED_DATE,'%d %b %y, %I:%i %p') AS DATE, e.MAIL_STATUS, 
      CONCAT(ufrom.USER_FIRST_NAME,' ',ufrom.USER_LAST_NAME) AS U_NAME FROM EMAIL e  
LEFT JOIN USER_CONFIG ufrom
     ON ufrom.USER_ID = e.FROM_ADD 
LEFT JOIN USER_CONFIG uto
     ON uto.USER_ID = e.TO_ADD
WHERE 
     e.FROM_ADD=: e.FROM_ADD  
ORDER BY MAX(e.UPDATED_DATE) DESC, ufrom.USER_FIRST_NAME DESC 
LIMIT 0, 10 

表格

CREATE TABLE IF NOT EXISTS USER_CONFIG(
  USER_ID INT UNSIGNED NOT NULL,
  USER_FIRST_NAME VARCHAR(100) CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci' NOT NULL, 
  USER_LAST_NAME VARCHAR(100) CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci' NOT NULL, 
  PRIMARY KEY (USER_ID),
  INDEX idx_USER_CONFIG_id1 (USER_ID ASC)
)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_unicode_ci;

CREATE TABLE IF NOT EXISTS EMAIL (
 MAIL_NO INT UNSIGNED NOT NULL, 
 BIZ_ID VARCHAR(35) CHARACTER SET 'latin1' COLLATE 'latin1_bin' NOT NULL, 
 FROM_ADD INT UNSIGNED NOT NULL,  -- FOR EMAIL_TYPE EUCP, THIS WILL BE AGENT ID
 TO_ADD INT UNSIGNED DEFAULT NULL, -- FOR EMAIL_TYPE EUCP, THIS WILL BE CANDIDATE_ID
 EMAIL_SUBJECT VARCHAR(75) CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci' DEFAULT NULL, 
 MAIL_STATUS CHAR(1) CHARACTER SET 'latin1' COLLATE 'latin1_bin' DEFAULT 'A', 
 UPDATED_DATE DATETIME ON UPDATE CURRENT_TIMESTAMP,
 PRIMARY KEY (MAIL_NO,BIZ_ID),
 INDEX idx_EMAIL_id1 (FROM_ADD ASC),
 INDEX idx_EMAIL_id2 (TO_ADD ASC),
 INDEX idx_EMAIL_id3 (BIZ_ID ASC),
 INDEX idx_EMAIL_id4 (MAIL_STATUS ASC),
 INDEX idx_EMAIL_id5 (EMAIL_SUBJECT ASC), 
 INDEX idx_EMAIL_id6 (UPDATED_DATE ASC)  
)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_unicode_ci;

CREATE TABLE IF NOT EXISTS EMAIL_MESSAGE (
  MESSAGE_NO INT UNSIGNED NOT NULL, 
  BIZ_ID VARCHAR(35) CHARACTER SET 'latin1' COLLATE 'latin1_bin' NOT NULL, 
  SENDER INT UNSIGNED DEFAULT NULL, 
  MESSAGE TEXT CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci' DEFAULT NULL, 
  ATTACHMENT VARCHAR(255) CHARACTER SET 'latin1' COLLATE 'latin1_bin' DEFAULT NULL, 
  MESSAGE_STATUS CHAR(1) CHARACTER SET 'latin1' COLLATE 'latin1_bin' DEFAULT 'U', 
  READ_DATE DATETIME DEFAULT NULL, 
  SEND_DATE DATETIME DEFAULT CURRENT_TIMESTAMP, 
  PRIMARY KEY (MESSAGE_NO,BIZ_ID),
  INDEX idx_EMAIL_MESSAGE_id1 (SENDER ASC),
  INDEX idx_EMAIL_MESSAGE_id2 (MESSAGE_STATUS ASC)
)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_unicode_ci;

如果我必须自己查询表，我会使用

SELECT COUNT(*) AS UNREAD_MESSAGE_COUNT FROM EMAIL_MESSAGE 
  WHERE BIZ_ID= :BIZID AND MESSAGE_STATUS = 'U';

但我正在努力合并到上面给出的组合查询中。你能帮我解决这个问题吗？

Answer 1

最后收到的电子邮件和未读的计数（已收到）。

  SELECT e.MAIL_NO, e.BIZ_ID, e.FROM_ADD, e.TO_ADD, e.EMAIL_SUBJECT,  
  DATE_FORMAT(e.UPDATED_DATE,'%d %b %y, %I:%i %p') AS DATE, e.MAIL_STATUS, 
  CONCAT(ufrom.USER_FIRST_NAME,' ',ufrom.USER_LAST_NAME) AS U_NAME,if(UNREAD_MESSAGE_COUNT is null,0,UNREAD_MESSAGE_COUNT) FROM EMAIL e  
LEFT JOIN USER_CONFIG ufrom
 ON ufrom.USER_ID = e.TO_ADD
left join (SELECT COUNT(*) AS UNREAD_MESSAGE_COUNT,TO_ADD FROM EMAIL_MESSAGE         inner join EMAIL using (BIZ_ID)
WHERE MESSAGE_STATUS = 'U' group by TO_ADD) t on t.TO_ADD= e.TO_ADD
WHERE 
 e.TO_ADD=:TO_ADD
ORDER BY MAX(e.UPDATED_DATE) DESC, ufrom.USER_FIRST_NAME DESC 
LIMIT 0, 10 

已发送的电子邮件和未读已发送消息的计数：

  SELECT e.MAIL_NO, e.BIZ_ID, e.FROM_ADD, e.TO_ADD, e.EMAIL_SUBJECT,  
  DATE_FORMAT(e.UPDATED_DATE,'%d %b %y, %I:%i %p') AS DATE, e.MAIL_STATUS, 
  CONCAT(ufrom.USER_FIRST_NAME,' ',ufrom.USER_LAST_NAME) AS U_NAME,if(UNREAD_MESSAGE_COUNT is null,0,UNREAD_MESSAGE_COUNT) FROM EMAIL e  
LEFT JOIN USER_CONFIG ufrom
 ON ufrom.USER_ID = e.FROM_ADD 
left join (SELECT COUNT(*) AS UNREAD_MESSAGE_COUNT,FROM_ADD FROM EMAIL_MESSAGE         inner join EMAIL using (BIZ_ID)
WHERE MESSAGE_STATUS = 'U' group by FROM_ADD) t on t.FROM_ADD= e.FROM_ADD
WHERE 
 e.FROM_ADD=:FROM_ADD
ORDER BY MAX(e.UPDATED_DATE) DESC, ufrom.USER_FIRST_NAME DESC 
LIMIT 0, 10 

已编辑：- 添加 If count=null 为 0，并添加左连接以确保显示结果。

编辑 2：将子查询更改为仅计算发送给该用户的未读内容。

编辑 3：根据所需结果更新了第一个查询并添加了第二个查询。这应该可以解决问题。您可能想要第一个。