search
HomeDatabaseMysql TutorialHow to Accurately Count Approved Comments in MySQL Using SUM()?

How to Accurately Count Approved Comments in MySQL Using SUM()?

Counting with IF Condition in MySQL Query

Your objective is to retrieve the count of approved comments for news articles. However, your current query is returning a minimum value of 1 for the comments column, even if no comments exist for a particular article.

To resolve this issue, swap out the count() function with sum() in your query. Let's dive into the specifics:

SELECT
    ccc_news . * , 
    SUM(if(ccc_news_comments.id = 'approved', 1, 0)) AS comments
FROM
    ccc_news
    LEFT JOIN
        ccc_news_comments
    ON
        ccc_news_comments.news_id = ccc_news.news_id
WHERE
    `ccc_news`.`category` = 'news_layer2'
    AND `ccc_news`.`status` = 'Active'
GROUP BY
    ccc_news.news_id
ORDER BY
    ccc_news.set_order ASC
LIMIT 20 

How it Works:

The sum() function evaluates every TRUE expression to 1 and FALSE expressions to 0, effectively returning the total number of approved comments.

This updated query now provides accurate counts, showing whether each news article has approved comments or not.

The above is the detailed content of How to Accurately Count Approved Comments in MySQL Using SUM()?. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
What Are the Limitations of Using Views in MySQL?What Are the Limitations of Using Views in MySQL?May 14, 2025 am 12:10 AM

MySQLviewshavelimitations:1)Theydon'tsupportallSQLoperations,restrictingdatamanipulationthroughviewswithjoinsorsubqueries.2)Theycanimpactperformance,especiallywithcomplexqueriesorlargedatasets.3)Viewsdon'tstoredata,potentiallyleadingtooutdatedinforma

Securing Your MySQL Database: Adding Users and Granting PrivilegesSecuring Your MySQL Database: Adding Users and Granting PrivilegesMay 14, 2025 am 12:09 AM

ProperusermanagementinMySQLiscrucialforenhancingsecurityandensuringefficientdatabaseoperation.1)UseCREATEUSERtoaddusers,specifyingconnectionsourcewith@'localhost'or@'%'.2)GrantspecificprivilegeswithGRANT,usingleastprivilegeprincipletominimizerisks.3)

What Factors Influence the Number of Triggers I Can Use in MySQL?What Factors Influence the Number of Triggers I Can Use in MySQL?May 14, 2025 am 12:08 AM

MySQLdoesn'timposeahardlimitontriggers,butpracticalfactorsdeterminetheireffectiveuse:1)Serverconfigurationimpactstriggermanagement;2)Complextriggersincreasesystemload;3)Largertablesslowtriggerperformance;4)Highconcurrencycancausetriggercontention;5)M

MySQL: Is it safe to store BLOB?MySQL: Is it safe to store BLOB?May 14, 2025 am 12:07 AM

Yes,it'ssafetostoreBLOBdatainMySQL,butconsiderthesefactors:1)StorageSpace:BLOBscanconsumesignificantspace,potentiallyincreasingcostsandslowingperformance.2)Performance:LargerrowsizesduetoBLOBsmayslowdownqueries.3)BackupandRecovery:Theseprocessescanbe

MySQL: Adding a user through a PHP web interfaceMySQL: Adding a user through a PHP web interfaceMay 14, 2025 am 12:04 AM

Adding MySQL users through the PHP web interface can use MySQLi extensions. The steps are as follows: 1. Connect to the MySQL database and use the MySQLi extension. 2. Create a user, use the CREATEUSER statement, and use the PASSWORD() function to encrypt the password. 3. Prevent SQL injection and use the mysqli_real_escape_string() function to process user input. 4. Assign permissions to new users and use the GRANT statement.

MySQL: BLOB and other no-sql storage, what are the differences?MySQL: BLOB and other no-sql storage, what are the differences?May 13, 2025 am 12:14 AM

MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

MySQL Add User: Syntax, Options, and Security Best PracticesMySQL Add User: Syntax, Options, and Security Best PracticesMay 13, 2025 am 12:12 AM

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

MySQL: How to avoid String Data Types common mistakes?MySQL: How to avoid String Data Types common mistakes?May 13, 2025 am 12:09 AM

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools