问个SQL查询语句
有个客户表,其中一个字段里面存储的是电话号码,客户每买一次就登录一次电话号码,我现在想查询这个字段重复记录最多的,并且依次排列出来,这个SQL应该怎么写呢。
客户表名称 partylist
存储客户电话号码的字段是 phonum varchar(15)
表的结构大概是这样
张三 北京 0108956878
李四 上海 021545787
小小 上海 13800138000
小四 上海 13800138000
小吴 广州 0205855843
比如查询出来的结果是
13800138000 29次 小王
020184587 18次 小李
这样的,谢谢各位

TooptimizePHPcodeforreducedmemoryusageandexecutiontime,followthesesteps:1)Usereferencesinsteadofcopyinglargedatastructurestoreducememoryconsumption.2)LeveragePHP'sbuilt-infunctionslikearray_mapforfasterexecution.3)Implementcachingmechanisms,suchasAPC

PHPisusedforsendingemailsduetoitsintegrationwithservermailservicesandexternalSMTPproviders,automatingnotificationsandmarketingcampaigns.1)SetupyourPHPenvironmentwithawebserverandPHP,ensuringthemailfunctionisenabled.2)UseabasicscriptwithPHP'smailfunct

The best way to send emails is to use the PHPMailer library. 1) Using the mail() function is simple but unreliable, which may cause emails to enter spam or cannot be delivered. 2) PHPMailer provides better control and reliability, and supports HTML mail, attachments and SMTP authentication. 3) Make sure SMTP settings are configured correctly and encryption (such as STARTTLS or SSL/TLS) is used to enhance security. 4) For large amounts of emails, consider using a mail queue system to optimize performance.

CustomheadersandadvancedfeaturesinPHPemailenhancefunctionalityandreliability.1)Customheadersaddmetadatafortrackingandcategorization.2)HTMLemailsallowformattingandinteractivity.3)AttachmentscanbesentusinglibrarieslikePHPMailer.4)SMTPauthenticationimpr

Sending mail using PHP and SMTP can be achieved through the PHPMailer library. 1) Install and configure PHPMailer, 2) Set SMTP server details, 3) Define the email content, 4) Send emails and handle errors. Use this method to ensure the reliability and security of emails.

ThebestapproachforsendingemailsinPHPisusingthePHPMailerlibraryduetoitsreliability,featurerichness,andeaseofuse.PHPMailersupportsSMTP,providesdetailederrorhandling,allowssendingHTMLandplaintextemails,supportsattachments,andenhancessecurity.Foroptimalu

The reason for using Dependency Injection (DI) is that it promotes loose coupling, testability, and maintainability of the code. 1) Use constructor to inject dependencies, 2) Avoid using service locators, 3) Use dependency injection containers to manage dependencies, 4) Improve testability through injecting dependencies, 5) Avoid over-injection dependencies, 6) Consider the impact of DI on performance.

PHPperformancetuningiscrucialbecauseitenhancesspeedandefficiency,whicharevitalforwebapplications.1)CachingwithAPCureducesdatabaseloadandimprovesresponsetimes.2)Optimizingdatabasequeriesbyselectingnecessarycolumnsandusingindexingspeedsupdataretrieval.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Linux new version
SublimeText3 Linux latest version

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
