sql - 如何在 MYSQL 中优化此查询？需要做什么

Question

请向下滚动到“25/08/2010 更新”。

我有一个已转换为 View 的查询。它运行非常缓慢，因为(据我所知)连接表上的索引存在几个问题。

---

explain select * from view_ed_abc_print

---

如您所见，我有一个使用 where、temporary 和 filesort 的表“a”，其中包含 4659 行，据我所知，这意味着它必须为返回的每一行运行 4659 行。

我省略了查询，因为它真的很长，而且这里的格式很糟糕(它来自一个 View ，所以导致了一些问题

有人有什么想法吗？

---

感谢您到目前为止的回答。我已经为所有外键创建了索引，并向 publicationtypes 和 audittypes 表添加了一个主键(哎呀，那太傻了)

无论如何，这是新的解释

这是查询的 where/from 部分(很抱歉由于某种原因格式丢失了)

 from
   (
      (
         (
            (
               (
                  `auau7859_aba`.`ed_abc_publication_audits` `a` use index(pubid)
                  left join `auau7859_aba`.`public_publications` `p` on
                  (
                     (`p`.`pubid` = `a`.`audit_pubid`)
                  )
               )
               left join `auau7859_aba`.`ed_aba_frequencies` on
               (
                  (
                     `auau7859_aba`.`ed_aba_frequencies`.`frequencyid` = `p`.`pub_frequencyid`
                  )
               )
            )
            left join `auau7859_aba`.`ed_abc_publicationtypes` on
            (
               (
                  `auau7859_aba`.`ed_abc_publicationtypes`.`publicationtypeid` = `p`.`pub_type`
               )
            )
         )
         left join `auau7859_aba`.`ed_abc_audittypes` on
         (
            (`a`.`audit_type` = `auau7859_aba`.`ed_abc_audittypes`.`audittypeid`)
         )
      )
      left join `auau7859_aba`.`Members` `m` on((`m`.`MemID` = `p`.`pub_memid`))
   )   where ((`a`.`audit_active` = 1) and (`p`.`pub_unfinancial` = 0))
   order by `a`.`audit_anps` desc

---

查询时间现在好多了，但是我想知道是否有可能让表“a”开始使用该键，而不是我读过的“使用文件排序”真的很慢。

---

根据要求，这里是相关表格的定义。ed_abc_publication_audits

     CREATE TABLE `ed_abc_publication_audits` (
            `auditid` INT(11) NOT NULL AUTO_INCREMENT,
            `audit_period` INT(11) NULL DEFAULT '0',
            `audit_year` INT(11) NULL DEFAULT '0',
            `audit_pubid` INT(11) NULL DEFAULT '0',
            `audit_frequencyid` INT(11) NULL DEFAULT '0',
            `audit_issues` VARCHAR(50) NULL DEFAULT NULL,
            `audit_exclusions` TINYINT(4) NULL DEFAULT '0',
            `deprecated_dayspublished` INT(11) NULL DEFAULT '0',
            `audit_specialpublishingday` VARCHAR(50) NULL DEFAULT NULL,
            `audit_bumperissues` TINYINT(4) NULL DEFAULT '0',
            `audit_bumperissuedates` TEXT NULL,
            `audit_bumperissuelinked` TINYINT(4) NULL DEFAULT '0',
            `audit_excludeddates` TEXT NULL,
            `audit_coverprice` DECIMAL(10,2) NULL DEFAULT '0.00',
            `audit_coverpriceday` VARCHAR(100) NULL DEFAULT '0',
            `audit_coverprice2` DECIMAL(10,2) NULL DEFAULT '0.00',
            `audit_coverprice2day` VARCHAR(100) NULL DEFAULT '0',
            `audit_coverprice3` DECIMAL(10,2) NULL DEFAULT '0.00',
            `audit_coverprice3day` VARCHAR(100) NULL DEFAULT '0',
            `audit_osmoney` INT(11) NULL DEFAULT '0',
            `audit_type` INT(11) NULL DEFAULT '0',
            `audit_anps` INT(11) NULL DEFAULT '0',
            `audit_inexcess` TINYINT(4) NULL DEFAULT '0',
            `audit_periodadjustment` TINYINT(4) NULL DEFAULT '0',
            `audit_periodadjustmentvalue` INT(11) NULL DEFAULT '0',
            `audit_nznps` INT(11) NULL DEFAULT '0',
            `audit_nzinexcess` TINYINT(4) NULL DEFAULT '0',
            `audit_othercountries` INT(11) NULL DEFAULT '0',
            `audit_ocinexcess` TINYINT(4) NULL DEFAULT '0',
            `audit_inclaccomairlinesales` DOUBLE NULL DEFAULT '0',
            `audit_incleducationalsales` DOUBLE NULL DEFAULT '0',
            `audit_incleventsales` DOUBLE NULL DEFAULT '0',
            `audit_inclmultiplepublicationsales` DOUBLE NULL DEFAULT '0',
            `audit_bundledsales` DOUBLE NULL DEFAULT NULL,
            `audit_exclaustraliaother` INT(11) NULL DEFAULT '0',
            `audit_exclinexcess` TINYINT(4) NULL DEFAULT '0',
            `audit_nimcopiesprinted` INT(11) NULL DEFAULT '0',
            `audit_nimcopiesdelivered` INT(11) NULL DEFAULT '0',
            `audit_nimcopiesmailed` INT(11) NULL DEFAULT '0',
            `audit_remarks` TEXT NULL,
            `audit_coverprice4day` INT(10) NULL DEFAULT NULL,
            `audit_coverprice4` DECIMAL(10,2) NULL DEFAULT NULL COMMENT 'CoverPrice4',
            `audit_issuesaudited` INT(10) NULL DEFAULT NULL,
            `audit_nonpublishingdates` VARCHAR(45) NULL DEFAULT NULL,
            `audit_digital_anps` INT(10) NULL DEFAULT NULL,
            `audit_digital_inclaccomairlinesales` DOUBLE NULL DEFAULT NULL,
            `audit_digital_incleducationalsales` DOUBLE NULL DEFAULT NULL,
            `audit_digital_incleventsales` DOUBLE NULL DEFAULT NULL,
            `audit_digital_inclmultiplepublicationsales` DOUBLE NULL DEFAULT NULL,
            `audit_digital_bundledsalesdigital` DOUBLE NOT NULL,
            `deprecated_FirstSignatoryName` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_FirstSignatoryEmail` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_SecondSignatoryName` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_SecondSignatoryEmail` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_FormStatus` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_dateSubmitted` VARCHAR(255) NULL DEFAULT NULL,
            `audit_datecreated` TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
            `deprecated_dateSignatoryApproved` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_AuditorName` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_AuditorEmail` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_dateAuditorApproved` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_nPeriod` INT(11) NULL DEFAULT NULL,
            `deprecated_nYear` INT(10) NULL DEFAULT NULL,
            `audit_totalissuesaudited` INT(10) NULL DEFAULT NULL,
            `audit_parentpublication` INT(10) NULL DEFAULT NULL,
            `audit_auditenddate` VARCHAR(20) NULL DEFAULT NULL,
            `audit_digital_bumperissuedates` TEXT NULL,
            `audit_digital_bumperissues` TINYINT(4) NULL DEFAULT NULL,
            `audit_digital_bumperissueslinked` TINYINT(4) NULL DEFAULT NULL,
            `audit_digital_coverprice2` DECIMAL(10,2) NULL DEFAULT NULL,
            `audit_digital_coverprice2day` VARCHAR(25) NULL DEFAULT NULL,
            `audit_digital_coverprice3` DECIMAL(10,2) NULL DEFAULT NULL,
            `audit_digital_coverprice3day` VARCHAR(25) NULL DEFAULT NULL,
            `audit_digital_coverprice4` DECIMAL(10,2) NULL DEFAULT NULL,
            `audit_digital_coverprice4day` VARCHAR(25) NULL DEFAULT NULL,
            `audit_digital_coverprice` DECIMAL(18,2) NULL DEFAULT NULL,
            `audit_digital_coverpriceday` VARCHAR(25) NULL DEFAULT NULL,
            `audit_daysbetween` INT(11) NULL DEFAULT NULL,
            `audit_digital_excludeddates` TEXT NULL,
            `audit_digital_issuesaudited` INT(11) NULL DEFAULT NULL,
            `audit_digital_issues` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_lodgementstatus` VARCHAR(255) NULL DEFAULT NULL,
            `deprecated_lodgementtype` VARCHAR(255) NULL DEFAULT NULL,
            `audit_nimaveragecopiesdelivered` INT(11) NULL DEFAULT NULL,
            `audit_nimaveragecopiesmailed` INT(11) NULL DEFAULT NULL,
            `audit_nimaveragecopiesprinted` INT(11) NULL DEFAULT NULL,
            `audit_digital_nonpublishingdates` VARCHAR(45) NULL DEFAULT NULL,
            `Remarks` TEXT NULL,
            `audit_digital_remarks` TEXT NULL,
            `deprecated_s2complete` INT(11) NULL DEFAULT NULL,
            `deprecated_s3complete` INT(11) NULL DEFAULT NULL,
            `audit_stageid` INT(11) NULL DEFAULT NULL,
            `audit_periodenddate` DATE NULL DEFAULT NULL,
            `audit_periodstartdate` DATE NULL DEFAULT NULL,
            `audit_dayspublished` SET('mon','tue','wed','thu','fri','sat','sun') NULL DEFAULT NULL,
            `audit_active` TINYINT(1) UNSIGNED NULL DEFAULT '1',
            `deprecated_auditor_name` VARCHAR(255) NULL DEFAULT NULL COMMENT 'abc_status',
            `audit_auditor_id` INT(10) NULL DEFAULT NULL COMMENT 'This is the auditor ID that has been pulled from the abc status table. WARNING: THIS IS from abcUSERS',
            `deprecated_auditor_email` VARCHAR(255) NULL DEFAULT NULL COMMENT 'abc_status',
            `deprecated_publisher_name` VARCHAR(255) NULL DEFAULT NULL COMMENT 'abc_status',
            `audit_author_id` INT(10) NULL DEFAULT NULL COMMENT 'the author id from the abc_status. WARNING: ABCUsers TAble, not scmod',
            `deprecated_publisher_email` VARCHAR(255) NULL DEFAULT NULL COMMENT 'abc_status',
            PRIMARY KEY (`auditid`),
            INDEX `pubid` (`audit_pubid`),
            INDEX `audit_type` (`audit_type`),
            INDEX `audit_periodenddate` (`audit_periodenddate`),
            INDEX `audit_periodstartdate` (`audit_periodstartdate`),
            INDEX `audit_anps` (`audit_anps`),
            INDEX `orderby` (`audit_pubid`, `audit_anps`)
        )
        COMMENT='aba_cmt'
        COLLATE='latin1_swedish_ci'
        ENGINE=MyISAM
        ROW_FORMAT=DEFAULT
        AUTO_INCREMENT=5483

public_publications 表 (p)

CREATE TABLE `public_publications` (
    `pubid` INT(11) NOT NULL AUTO_INCREMENT,
    `pub_memid` DOUBLE NULL DEFAULT NULL,
    `pub_ledger_code` VARCHAR(255) NULL DEFAULT NULL,
    `pub_title` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_previousname` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_tSummaryTitle` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_bBillPublisher` DOUBLE NULL DEFAULT NULL,
    `deprecated_bBillOtherMember` DOUBLE NULL DEFAULT NULL,
    `deprecated_BillMemID` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_BBillAdHocAddress` DOUBLE NULL DEFAULT NULL,
    `pub_address` VARCHAR(255) NULL DEFAULT NULL,
    `pub_suburb` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_state1` VARCHAR(255) NULL DEFAULT NULL,
    `pub_mlocation` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_postcode` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_membership_amount` DOUBLE NULL DEFAULT NULL,
    `deprecated_receipt_date` VARCHAR(255) NULL DEFAULT NULL,
    `pub_abc` DOUBLE NULL DEFAULT NULL,
    `pub_unfinancial` TINYINT(1) NULL DEFAULT '0',
    `pub_auditmemid` DOUBLE NULL DEFAULT NULL,
    `deprecated_auditorid` DOUBLE NULL DEFAULT NULL,
    `pub_audittype` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_PubType` DOUBLE NULL DEFAULT NULL,
    `pub_classification` INT(11) NULL DEFAULT NULL,
    `deprecated_OldPubID` DOUBLE NULL DEFAULT NULL,
    `deprecated_OldCompanyID` DOUBLE NULL DEFAULT NULL,
    `pub_contactid` DOUBLE NULL DEFAULT NULL,
    `pub_auditremarks` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_bGovernment` DOUBLE NULL DEFAULT NULL,
    `deprecated_bExGovernment` DOUBLE NULL DEFAULT NULL,
    `deprecated_dDateJoined` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_tDaysPublished` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_stateid` VARCHAR(50) NULL DEFAULT NULL,
    `deprecated_PublisherCost` DOUBLE NULL DEFAULT NULL,
    `pub_magazinecategory` DOUBLE NULL DEFAULT NULL,
    `deprecated_dayspublished` DOUBLE NULL DEFAULT NULL,
    `pub_frequency` VARCHAR(255) NULL DEFAULT NULL,
    `pub_type` INT(11) NULL DEFAULT NULL,
    `pub_subtype` VARCHAR(255) NULL DEFAULT NULL,
    `deprecated_MYOBExport` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodJAN-JUNE` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodJUL-DEC` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodJAN-MAR` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodAPR-JUN` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodJUL-SEPT` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodOCT-DEC` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodApr-Mar` DOUBLE NULL DEFAULT NULL,
    `deprecated_periodOct-Sept` DOUBLE NULL DEFAULT NULL,
    `deprecated_UnfinancialDate` VARCHAR(255) NULL DEFAULT NULL,
    `pub_location` VARCHAR(255) NULL DEFAULT NULL,
    `Address` VARCHAR(255) NULL DEFAULT NULL COMMENT 'Address',
    `deprecated_AuditorName` VARCHAR(255) NULL DEFAULT NULL COMMENT 'use pub_auditorid instead. ',
    `deprecated_AuditorEmail` VARCHAR(255) NULL DEFAULT NULL COMMENT 'use pub_auditorid instead. ',
    `pub_auditflag` VARCHAR(45) NULL DEFAULT NULL,
    `pub_datemodified` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `pub_website` VARCHAR(255) NULL DEFAULT NULL,
    `pub_mastheadurl` VARCHAR(255) NULL DEFAULT NULL,
    `pub_frequencyid` INT(11) NULL DEFAULT NULL,
    `pub_nimparentpubid` INT(11) NULL DEFAULT NULL,
    `pub_active` TINYINT(4) NULL DEFAULT NULL,
    `remove_datemodified` TIMESTAMP NULL DEFAULT NULL,
    `pub_datecreated` TIMESTAMP NULL DEFAULT NULL,
    `pub_dayspublished` SET('mon','tue','wed','thu','fri','sat','sun') NULL DEFAULT NULL,
    `pub_state` VARCHAR(10) NULL DEFAULT NULL,
    `pub_contact_vote` INT(10) NULL DEFAULT NULL,
    `pub_contact_auditletter1` INT(10) NULL DEFAULT NULL,
    `pub_contact_auditletter2` INT(10) NULL DEFAULT NULL,
    `pub_auditorid` INT(10) NULL DEFAULT NULL COMMENT 'Put the user id of the auditor in this field for ABC elodgement. (see sc_module_users user_id, listed in the module > users page in edata backend)',
    `pub_next_audit_period` INT(10) NULL DEFAULT NULL,
    `pub_next_audit_type` INT(10) NULL DEFAULT NULL,
    PRIMARY KEY (`pubid`),
    INDEX `Index_2` (`pub_title`),
    INDEX `Unfinancial` (`pub_unfinancial`),
    INDEX `lPublicationType` (`pub_type`)
)
COLLATE='latin1_swedish_ci'
ENGINE=MyISAM
ROW_FORMAT=DEFAULT
AUTO_INCREMENT=20000

成员(m)表

CREATE TABLE `Members` (
    `MemID` INT(11) NOT NULL AUTO_INCREMENT,
    `ABC` INT(11) NOT NULL,
    `Mem_Type_ID` SMALLINT(6) NOT NULL,
    `Membership Status` VARCHAR(80) NULL DEFAULT NULL,
    `reference` VARCHAR(255) NULL DEFAULT NULL,
    `CABReference` VARCHAR(50) NULL DEFAULT NULL,
    `Company_Name` VARCHAR(255) NOT NULL,
    `Street_Address` VARCHAR(255) NULL DEFAULT NULL,
    `Street_Address_Line2` VARCHAR(100) NULL DEFAULT NULL,
    `Suburb` VARCHAR(255) NULL DEFAULT NULL,
    `State` VARCHAR(255) NULL DEFAULT NULL,
    `Post_Code` VARCHAR(255) NULL DEFAULT NULL,
    `unfinancial` TINYINT(1) NULL DEFAULT NULL,
    `file` VARCHAR(255) NULL DEFAULT NULL,
    `Phone` VARCHAR(255) NULL DEFAULT NULL,
    `Fax` VARCHAR(255) NULL DEFAULT NULL,
    `WebsiteAddress` VARCHAR(70) NULL DEFAULT NULL,
    `TempAddress` VARCHAR(255) NULL DEFAULT NULL,
    `ABCWebsitePassword` VARCHAR(10) NULL DEFAULT NULL,
    `ABCWebsiteUsername` VARCHAR(10) NULL DEFAULT NULL,
    `CABWebsiteUsername` VARCHAR(10) NULL DEFAULT NULL,
    `CABWebsitePassword` VARCHAR(10) NULL DEFAULT NULL,
    `MembershipAmount` DOUBLE NULL DEFAULT NULL,
    `MYOBExport` TINYINT(1) NULL DEFAULT NULL,
    `MYOBTaxCode` VARCHAR(3) NULL DEFAULT NULL,
    `Date_Last_Payment` VARCHAR(40) NULL DEFAULT NULL,
    `Date_Admitted` VARCHAR(40) NULL DEFAULT NULL,
    `Date_Resigned` VARCHAR(40) NULL DEFAULT NULL,
    `masthead_url` VARCHAR(255) NULL DEFAULT NULL,
    `masthead_report` TINYINT(1) NULL DEFAULT '0',
    `masthead_image` VARCHAR(255) NULL DEFAULT NULL,
    `masthead_description` TEXT NULL,
    `masthead_title` VARCHAR(255) NULL DEFAULT NULL,
    PRIMARY KEY (`MemID`),
    INDEX `MemID` (`MemID`)
)
COLLATE='latin1_swedish_ci'
ENGINE=MyISAM
ROW_FORMAT=DEFAULT
AUTO_INCREMENT=12349

至于其他表，它们是相当无关紧要的，尽管如果您认为它们相关，很乐意发布它们，请对其发表评论。

谢谢。这是最新的解释查询结果:

快速总结

1. 为所有外键添加了索引，并为 publicationtypes 和 audittypes 表添加了主键(这些只是查找表)
2. 为 public_publications 和 publications_audit 表添加了排序索引

这些大大减少了查询时间，但仍然运行了大约 0.4 秒，总共只有 4300 行左右。

如果您有任何建议，我们将不胜感激!

---

25/08/2010 更新

经过更多的调试，我意识到如果我从我的 select 子句中删除所有的废话，查询运行得非常快。现在我想知道我的 select 子句中是否有什么东西让它运行得这么慢。

谁能指出这个选择查询有些慢:

 `p`.`pub_memid` AS `pub_memid`,
   `a`.`audit_inexcess` AS `audit_inexcess`,
   `a`.`auditid` AS `auditid`,
   `a`.`audit_period` AS `audit_period`,
   year(`a`.`audit_periodenddate`) AS `audit_year`,
   `p`.`pub_unfinancial` AS `pub_unfinancial`,
   `p`.`pub_title` AS `pub_title`,
   concat(`p`.`pub_title`,_latin1'{%}',`p`.`pubid`) AS `pub_title@display`,
   `p`.`pubid` AS `pubid`,
   `a`.`audit_periodstartdate` AS `audit_periodstartdate`,
   date_format(`a`.`audit_periodstartdate`,_latin1'%b %y') AS `audit_periodstartdate@display`,
   `a`.`audit_periodenddate` AS `audit_periodenddate`,
   date_format(`a`.`audit_periodenddate`,_latin1'%b %y') AS `audit_periodenddate@display`,
   `a`.`audit_type` AS `audit_type`,
   `auau7859_aba`.`ed_abc_audittypes`.`audittype_title` AS `audittype_title`,
   `p`.`pub_state` AS `pub_state`,
   `p`.`pub_location` AS `pub_location`,
   `p`.`pub_dayspublished` AS `pub_dayspublished`,
   `auau7859_aba`.`ed_aba_frequencies`.`frequency_title` AS `frequency_title`,
   `a`.`audit_issues` AS `audit_issues`,
   `a`.`audit_issuesaudited` AS `audit_issuesaudited`,
   if(((`a`.`audit_exclusions` <> 0) or (`a`.`audit_bumperissues` <> 0)),concat(_utf8'*',`a`.`audit_issuesaudited`),`a`.`audit_issuesaudited`) AS `audit_issuesaudited@display`,
   `a`.`audit_coverprice` AS `audit_coverprice`,
   concat(_utf8'$',`a`.`audit_coverprice`) AS `audit_coverprice@display`,
   `a`.`audit_coverpriceday` AS `audit_coverpriceday`,
   date_format(`a`.`audit_periodenddate`,_latin1'%b %y') AS `period_ending`,
   `a`.`audit_remarks` AS `audit_remarks`,
   `p`.`pub_type` AS `pub_type`,
   `auau7859_aba`.`ed_abc_publicationtypes`.`publicationtype_title` AS `publicationtype_title`,
   `a`.`audit_anps` AS `audit_anps`,
   if(`a`.`audit_inexcess`,concat(_utf8'+',format(`a`.`audit_anps`,0)),format(`a`.`audit_anps`,0)) AS `audit_anps@display`,
   if((`a`.`audit_inclaccomairlinesales` > 0),concat(format((`a`.`audit_inclaccomairlinesales` * 100),2),_utf8'%'),_utf8'') AS `audit_inclaccomairlinesales@display`,
   if((`a`.`audit_incleducationalsales` > 0),concat(format((`a`.`audit_incleducationalsales` * 100),2),_utf8'%'),_utf8'') AS `audit_incleducationalsales@display`,
   if((`a`.`audit_incleventsales` > 0),concat(format((`a`.`audit_incleventsales` * 100),2),_utf8'%'),_utf8'') AS `audit_incleventsales@display`,
   if((`a`.`audit_inclmultiplepublicationsales` > 0),concat(format((`a`.`audit_inclmultiplepublicationsales` * 100),2),_utf8'%'),_utf8'') AS `audit_inclmultiplepublicationsales@display`,
   if((`a`.`audit_bundledsales` > 0),concat(format((`a`.`audit_bundledsales` * 100),2),_utf8'%'),_utf8'') AS `audit_bundledsales@display`,
   if((`a`.`audit_nznps` > 0),format(`a`.`audit_nznps`,0),_utf8'') AS `audit_nznps@display`,
   if((`a`.`audit_othercountries` > 0),format(`a`.`audit_othercountries`,0),_utf8'') AS `audit_othercountries@display`,
   if((`a`.`audit_exclaustraliaother` > 0),format(`a`.`audit_exclaustraliaother`,0),_utf8'') AS `audit_exclaustraliaother@display`,
   `a`.`audit_inclaccomairlinesales` AS `audit_inclaccomairlinesales`,
   `a`.`audit_incleducationalsales` AS `audit_incleducationalsales`,
   `a`.`audit_incleventsales` AS `audit_incleventsales`,
   `a`.`audit_inclmultiplepublicationsales` AS `audit_inclmultiplepublicationsales`,
   `a`.`audit_bundledsales` AS `audit_bundledsales`,
   `a`.`audit_nznps` AS `audit_nznps`,
   `a`.`audit_othercountries` AS `audit_othercountries`,
   `a`.`audit_exclaustraliaother` AS `audit_exclaustraliaother`,
   `p`.`pub_mastheadurl` AS `pub_mastheadurl`,
   `a`.`auditid` AS `audit_mastheadlink`,
   concat(ifnull(`a`.`audit_bumperissuedates`,_latin1''),_latin1'{%}',ifnull(`a`.`audit_excludeddates`,_latin1''),_latin1'{%}',ifnull(`a`.`audit_remarks`,_latin1'')) AS `audit_remarks@display`,
   if((ifnull(`a`.`audit_specialpublishingday`,_latin1'') <> _latin1''),concat(ifnull(`p`.`pub_dayspublished`,_latin1''),_latin1'{%}',ifnull(`a`.`audit_specialpublishingday`,_latin1'')),`p`.`pub_dayspublished`) AS `pub_dayspublished@display`,
   `a`.`audit_parentpublication` AS `audit_parentpublication`,
   if((ifnull(`p`.`pub_nimparentpubid`,0) > 0),(select `nimpub`.`pub_title` AS `pub_title` from `auau7859_aba`.`public_publications` `nimpub` where (`nimpub`.`pubid` = `p`.`pub_nimparentpubid`)),_latin1'') AS `audit_parentpublication@display`,
   `a`.`audit_digital_anps` AS `audit_digital_anps`,
   if((`a`.`audit_digital_anps` > 0),format(`a`.`audit_digital_anps`,0),_utf8'') AS `audit_digital_anps@display`,
   `a`.`audit_digital_bumperissuedates` AS `audit_digital_bumperissuedates`,
   `a`.`audit_digital_bumperissues` AS `audit_digital_bumperissues`,
   `a`.`audit_digital_bumperissueslinked` AS `audit_digital_bumperissueslinked`,
   `a`.`audit_digital_coverprice` AS `audit_digital_coverprice`,
   concat(_utf8'$',`a`.`audit_digital_coverprice`) AS `audit_digital_coverprice@display`,
   `a`.`audit_digital_coverprice2` AS `audit_digital_coverprice2`,
   `a`.`audit_digital_coverprice2day` AS `audit_digital_coverprice2day`,
   `a`.`audit_digital_coverprice3` AS `audit_digital_coverprice3`,
   `a`.`audit_digital_coverprice3day` AS `audit_digital_coverprice3day`,
   `a`.`audit_digital_coverprice4` AS `audit_digital_coverprice4`,
   `a`.`audit_digital_coverprice4day` AS `audit_digital_coverprice4day`,
   `a`.`audit_digital_coverpriceday` AS `audit_digital_coverpriceday`,
   `a`.`audit_digital_excludeddates` AS `audit_digital_excludeddates`,
   `a`.`audit_digital_inclaccomairlinesales` AS `audit_digital_inclaccomairlinesales`,
   if((`a`.`audit_digital_inclaccomairlinesales` > 0),concat(format(`a`.`audit_digital_inclaccomairlinesales`,2),_utf8'%'),_utf8'') AS `audit_digital_inclaccomairlinesales@display`,
   `a`.`audit_digital_incleducationalsales` AS `audit_digital_incleducationalsales`,
   if((`a`.`audit_digital_incleducationalsales` > 0),concat(format(`a`.`audit_digital_incleducationalsales`,2),_utf8'%'),_utf8'') AS `audit_digital_incleducationalsales@display`,
   `a`.`audit_digital_incleventsales` AS `audit_digital_incleventsales`,
   if((`a`.`audit_digital_incleventsales` > 0),concat(format(`a`.`audit_digital_incleventsales`,2),_utf8'%'),_utf8'') AS `audit_digital_incleventsales@display`,
   `a`.`audit_digital_inclmultiplepublicationsales` AS `audit_digital_inclmultiplepublicationsales`,
   if((`a`.`audit_digital_inclmultiplepublicationsales` > 0),concat(format(`a`.`audit_digital_inclmultiplepublicationsales`,0),_utf8'%'),_utf8'') AS `audit_digital_inclmultiplepublicationsales@display`,
   `a`.`audit_digital_bundledsalesdigital` AS `audit_digital_bundledsalesdigital`,
   if((`a`.`audit_digital_bundledsalesdigital` > 0),concat(format(`a`.`audit_digital_bundledsalesdigital`,2),_utf8'%'),_utf8'') AS `audit_digital_bundledsalesdigital@display`,
   `a`.`audit_digital_issues` AS `audit_digital_issues`,
   `a`.`audit_digital_issuesaudited` AS `audit_digital_issuesaudited`,
   if(((ifnull(`a`.`audit_digital_excludeddates`,_latin1'') <> _latin1'') or (`a`.`audit_digital_bumperissues` <> 0)),concat(_utf8'*',`a`.`audit_digital_issuesaudited`),`a`.`audit_digital_issuesaudited`) AS `audit_digital_issuesaudited@display`,
   `a`.`audit_digital_nonpublishingdates` AS `audit_digital_nonpublishingdates`,
   `a`.`audit_digital_remarks` AS `audit_digital_remarks`,
   concat(ifnull(`a`.`audit_digital_bumperissuedates`,_latin1''),_latin1'{%}',ifnull(`a`.`audit_digital_excludeddates`,_latin1''),_latin1'{%}',ifnull(`a`.`audit_digital_remarks`,_latin1'')) AS `audit_digital_remarks@display`,
   `m`.`Company_Name` AS `publisher`,
   `auau7859_aba`.`ed_abc_publicationtypes`.`publicationtype_abbreviation` AS `publicationtype_abbreviation`

Answer 1

更详细的问题...

根据我在查询中阅读的内容，您正在执行所有左联接...因此指示左侧表中的所有记录，而不管右侧表中是否存在基于其联接的匹配项。在这种情况下，最内层来自...

ed_abc_publication_audits left-joined to public_publications

但是您的 where 子句通过

在两边限定了一个值

(a.audit_active = 1) and (p.pub_unfinancial = 0)

对我来说，这意味着一个 INNER JOIN，其中记录必须存在于每一侧...

然后您对 auau7859_aba.ed_aba_frequencies、ed_abc_publicationtypes、ed_abc_audittypes 和 Members 执行 LEFT JOINs....

您是否期望在这些更深层次的连接中出现一些不匹配并因此期望 NULL 值，或者您想要的是它们最终在所有级别连接在一起的地方。

但是，看起来其他表的左连接更像是一个查找/引用表，记录应该始终存在。例如

每次发布​​审核都将始终具有有效的“审核类型”

每个出版物都将始终具有“频率 ID”、“出版物类型”和“成员”

我的解释正确吗？？？查找表总是会有匹配的记录吗？如果是，哪些...如果可选哪些...

根据您的回答，尝试以下查询...如果您了解您的数据、关系并且可以自行优化，STRAIGHT_JOIN 会非常强大，这是驱动系统其余部分的关键表...

SELECT STRAIGHT_JOIN
        a.*,
        p.*
    FROM 
        auau7859_aba.ed_abc_publication_audits a
            left join auau7859_aba.ed_abc_audittypes atypes
                ON a.audit_type = atypes.audittypeid,
        auau7859_aba.public_publications p 
            left join auau7859_aba.ed_aba_frequencies f
                ON p.pub_frequencyid = f.frequencyid
            left join auau7859_aba.ed_abc_publicationtypes t
                ON p.pub_type = t.publicationtypeid
            left join auau7859_aba.Members m 
                on p.pub_memid = m.MemID
    where 
            a.audit_pubid = p.pubid
        and a.Audit_Active = 1
        and p.pub_unfinancial = 0