COUNT ( column ) counts all non-NULL occurences (or should …
COUNT ( * ) counts all rows.
Friday, April 17, 2009
MySQL - Difference between Count(*) and count(column)
Subscribe to:
Post Comments (Atom)
skip to main |
skip to sidebar
Total Pageviews
Search This Blog
About Me
Recommended Articles
Labels
- Amazon Web Services (9)
- Android (2)
- AngularJS (2)
- Apache (72)
- Arduino (1)
- Assembly (19)
- Backup (39)
- Bash (8)
- Batch (14)
- Big Data (1)
- Book (1)
- Business Terminology (9)
- C (58)
- C# .NET (71)
- command (71)
- Computer Terminology (27)
- Data (1)
- Data mining (1)
- Debian (1)
- Debugging (52)
- Django (7)
- DNS (5)
- Docker (12)
- Drupal (125)
- Drupal 8 (12)
- Elasticsearch (1)
- English Vocabulary (56)
- ERP (3)
- Excel (4)
- Exchange Server (41)
- FFmpeg (4)
- Financial Management (1)
- FreeBSD (270)
- Game (1)
- Git (8)
- golang (54)
- Golden Saying Quotation (77)
- Good Articles (143)
- Google Sheets (1)
- Hardware (5)
- Health (8)
- HTML/CSS (46)
- HTML5 (3)
- IIS (14)
- ImageMagick (3)
- Internet of Things (IoT) (3)
- iPhone (2)
- Issue Tracker (2)
- IT Talk (4)
- Java (1)
- JavaScript (79)
- jQuery (61)
- jQWidgets (2)
- Linux (111)
- Load Balancing (19)
- Mac OS X (15)
- Magento (70)
- Magento 2 (13)
- Mail (17)
- Math (4)
- Miscellaneous (Others) (30)
- Money (11)
- MongoDB (2)
- MySQL (172)
- Network (13)
- News (4)
- Nginx (16)
- Node.js (3)
- Performance (31)
- Perl (12)
- pfSense (7)
- PHP (183)
- PhpStorm (3)
- PHPUnit (2)
- Postfix (3)
- PostgreSQL (2)
- PowerShell (5)
- PrestaShop (2)
- Printer (5)
- Programming Talk (152)
- Prometheus (1)
- Proxy (9)
- Python (19)
- Raspberry PI (4)
- Redis (3)
- Redundancy (8)
- Regular Expression (16)
- Restaurant (1)
- Reverse Engineering (1)
- Revision Control (32)
- RouterOS (1)
- Ruby (3)
- Script (8)
- Security (16)
- Software Quality Assurance and Testing (21)
- SQL Injection (11)
- SQL Server (77)
- SSH (5)
- Storage (3)
- Symfony (25)
- tmp (31)
- ToDo (181)
- Tools (156)
- Two-factor Authentication (3)
- Ubuntu (25)
- Unicode (32)
- Unix-like Tips (88)
- VB .NET (4)
- VBScript (66)
- Video conferencing (2)
- vim (101)
- VirtualBox (2)
- Virtualization (8)
- VMware (21)
- VoIP (1)
- VPN (14)
- Vue (3)
- Web Development (6)
- Windows API (1)
- Windows MIS (127)
- Windows Mobile (4)
- WPF (1)
- X Window (2)
- Xen (2)
- XML (6)
- Zend Studio (1)
Blog Archive
-
▼
2009
(742)
-
▼
April
(95)
- template auto run script
- change the default layout output of a node
- Alter table - 1205 lock wait timeout exceeded
- Get filename in php command line
- Quick and Dirty MySQL Backup
- php code template
- Using Per-Table Tablespaces
- Differences Between innodb_data_file_path and inno...
- Unknown table engine ‘InnoDB’
- psexec.exe wuauclt.exe tool works intermittently
- Default Javascript to the footer for better perfor...
- 職業貴賤觀念，害慘台灣軟體業
- Modulus With Bitwise Masks
- 如何學好外語
- 哪套軟體可以把影片轉成MP3 我用kmplayer轉的會爆音
- 投資心得
- INSERT UPDATE larget many file data rows for InnoDB
- Remove the 'Shortcut to...' Prefix on Shortcuts (A...
- FreeBSD MS SQL note
- DBConvert - DBSync for MS SQL & MySQL
- danny_library.php
- adminpack Windows Server 2003 Service Pack 2 Admin...
- Debugger 除錯器, Disassembling, Decompilation, revers...
- changing varchar to nvarchar - Erland Sommarskog
- change database columns from varchar to nvarchar i...
- SQLyog Sets New Standards for Data Synchronization...
- 狀況效能測試 - php 創始人正在 OSDC 講的 投影片
- strace your web server process
- Alternative PHP Cache (APC
- Siege is an http regression testing and benchmarki...
- Simple is Hard
- Speed up your web pages with YSlow
- An algorithm to find and resolve data differences ...
- MySQL Table Sync vs. SQLyog Job Agent
- Javascript - forward tool - copy clipboard filter ...
- MS SQL to MySQL Migration convert
- maatkit - 繼 SQLyog ，另一個管理 MySQL 的好工具！ Data Synchro...
- Synchronize MySQL Data Using SQLyog Job Agent
- SQLyog makes MySQL data synchronization and migrat...
- 開車練車心得
- How To Set Up A Load-Balanced MySQL Cluster
- How To Set Up Database Replication In MySQL
- Mirror Your Web Site With rsync
- How To Set Up A Loadbalanced High-Availability Apa...
- Apache Overview HOWTO: Load balancing
- MySQL or SQL Server: Look beyond politics and hype...
- first hand 第一手, 閱歷
- compelling 引人注目
- loftier, precepts
- ironclad - 鐵打的
- Draw someone like flies to honey
- disparate
- sacrifice
- Convert MyISAM tables to InnoDB
- 我們都老得太快 卻聰明得太遲＊
- Converting MyISAM to InnoDB
- MySQL migration convert MyISAM to InnoDB
- ubiquitous
- Restrictions on InnoDB Tables
- MySQL InnoDB: performance gains as well as some pi...
- InnoDB COUNT(id) - Why so slow?
- COUNT(*) for Innodb Tables
- MySQL - Difference between Count(*) and count(column)
- Some notes from Peter's MySQL/InnoDB Performance talk
- How to decrease InnoDB shutdown times
- START TRANSACTION, COMMIT, and ROLLBACK Syntax
- set global innodb fast=true;
- Optimizing for read performance
- Optimizing for write performance
- transaction in MySQL
- ibdata files do not shrink on database deletion [i...
- InnoDB write performance
- An introduction to foreign keys and referential in...
- greedy greediness in Regular Expression
- mysql constraint foreign key and more
- hack MySQL
- How to backup and import a MySQL InnoDB database
- Backing Up and Recovering an InnoDB Database
- MySQL Backup for InnoDB
- Detect encoding charset character set Western Euro...
- 檔名過長怎麼辦
- Split a string to an array by an array of positions
- get duplicate values from an array
- Version Control
- Scheduled task - automatically zip tar log file
- How to create Ctrl+Key shortcuts in Javascript
- Press any key to determine the javascript key code...
- Comparing Strings in PHP
- 壓死駱駝的最後一根草
- 沒有功勞也有苦勞的時代已經過去了
- 13億幽默 杭州打造朱德庸漫博館
- Customizing your Drupal user profile page
- Customising the user profile layout
- Setting Up Transactional Replication synchronizati...
- Display Attachment Attached Files by using Content...
-
▼
April
(95)
Popular Posts
- Magento Get Add to Cart URL of any Product
- 搬家愈多次，物質慾愈少？
- 寫程式是一種超能力
- 800a0004 Invalid algorithm specified / Invalid flags specified Persits ASP encryption
- Volume Shadow Copy Failed to create the storage area association
- NginX with FastCGI and C
- Squid transparent SSL proxy on pfSense
- Passing an argument to a Block View in Drupal 6
- Realtime File System Replication On FreeBSD
- simply accounting - How to connect to MySQL Server
No comments:
Post a Comment