fortigate 30

cause the engine to discard the full table scan using the index. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and created

In our usual SQL query, in fact, we have a lot to pay attention to the principle, since the implementation of SQL query optimization , this article will introduce 30 query optimization principles.The first principle to be noted1. To optimize the query, avoid full-table scanning as far as possible, and first consider establishing an index on the columns involved in the Where and order by.2. You should try to avoid null values in the WHERE clause to jud

cause the engine to discard the full table scan using the index. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and created

index. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and createdate10. Do not perform functions, arithmetic operations, or

Tags: select BSP cannot case it's Mat reference notation addMySQL Query SQL statements today, yesterday, nearly 7 days, nearly 30 days, this month, and last JanuaryThis article mainly introduces the MySQL query today, yesterday, nearly 7 days, nearly 30 days, this month, the January of SQL statements, generally in some statistical reports more commonly used this time period, the need for friends can refer t

This article is a MySQL in the optimization of SQL statements query commonly used 30 methods for detailed analysis of the introduction, the need for a friend under the reference 1. To optimize the query, you should try to avoid full table scans, and first consider indexing the where and the columns involved. 2. Avoid using the!= or 3. Avoid determining null values for fields in the WHERE clause, or cause the engine to discard the use of indexes

Objective of this articleIn 30 minutes you will understand what the regular expression is and have some basic knowledge of it so that you can use it in your own program or Web page. How to use this tutorial Most importantly-please give me 30 minutes, if you don't have the experience of using regular expressions, please don't try to get started in 30 seconds-unl

Label:--Number of medical releases released in the last 30 daysSELECT substr (a.feed_publish_time,6, 5) as ' Date ', COUNT (*) as ' medical say number ' from Xm_feed a WHEREDate_sub (Curdate (), INTERVAL) --the number of medical comments released in the last 30 daysSELECT substr (a.comm_create_time,6, 5) as ' Date ', COUNT (*) as ' medical commented number ' from Xm_feed_comment a WHERE date_sub (Curdate (

full table scan using the index. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and createdate10.Do not perform functions,

MySQL Query SQL statements today, yesterday, nearly 7 days, nearly 30 days, this month, and last JanuaryThis article mainly introduces the MySQL query today, yesterday, nearly 7 days, nearly 30 days, this month, the January of SQL statements, generally in some statistical reports more commonly used this time period, the need for friends can refer to the nextMySQL query today, yesterday, nearly 7 days, nearl

index. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and createdate10. Do not perform functions, arithmetic operations, or

. Such as:Select ID from t where substring (name,1,3) = ' abc '--name ID starting with ABCSelect ID from t where DATEDIFF (day,createdate, ' 2005-11-30 ') =0--' 2005-11-30 ' generated IDshould read:Select ID from t where name like ' abc% 'Select ID from t where createdate>= ' 2005-11-30 ' and createdate10. Do not perform functions, arithmetic operations, or other

I used to query the database today or yesterday, for the last seven days, for the last 30 days, and for the last month, the data was directly determined through php. This is an additional step, next I will introduce an article that uses SQL statements to calculate the data statements of the current day, yesterday, last 7 days, last 30 days, this month, and last month. In other words, the article table artic

What is the PHP framework? Who can define a PHP framework within 30 characters? Thank you. What is the PHP framework? Who can define a PHP framework within 30 characters? Thank you. This issue has been closed. Cause: non-technical questions are discussed. Reply content: What is the PHP framework? Who can define a PHP framework within 30 characters? Thank you

Article Title: Linux automatically shuts down after 30 minutes of no operation. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. Now let's try to write a small program that automatically shuts down. This program can run as a daemon. It will automatically shut down after a certain period of time (such as

In the classroom of Political Science in middle school, dialectical materialism tells us that everything includes two aspects of opposition and unity. To faithfully reflect the true nature of a transaction, we must adhere to the Contradiction Analysis Method of split into two parts, and make a comprehensive analysis of the contradiction, we must use a two-point theory to understand the nature of the transaction. Simply put, everything needs to see its good and bad sides. The same is true for it

Introduction: Recently, Microsoft's msdn blog author Ghassan chahine lists 30 best Windows Phone 7 tutorials The latest Windows Phone 7 platform contains 30 coolest Windows Phone development programs related to applications and games that interest all developers.Article. Links to all 30 best tutorial articles are as follows: Building a Windows Phon

In this experiment, we need to add two new 30 GB hard disks. [[Email protected] ~] # Uname- Linux zzsrv1.localdomain 3.10.0-123. el7.x86 _ 64 #1 SMP mon Jun 30 12:09:22 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux We can display the disk without restarting it. [[Email protected] ~] # Echo "---">/sys/class/scsi_host/host0/scan [[Email protected] ~] # Echo "---">/sys/class/scsi_host/host1/scan [[Email protected]

WHERE clause as much as possible, which will cause the engine to stop using the index for full table scanning. For example: Select ID from t where substring (name, 1, 3) = 'abc' -- id whose name starts with ABC Select ID from t where datediff (day, createdate, '2017-11-30 ') = 0 -- '2017-11-30' generated ID Should be changed: Select ID from t where name like 'abc %' Select ID from t where createdate> = '20

30 tips for win7 Tim sneath, senior director of platform promotion at Microsoft, a client Technical Expert, recently wrote an article on his blog "client platform men's meditation" to introduce 30 new features on Windows 7 users. Let's take a look at the following: Great, Windows 7 Beta has finally been released to the world! We are proud of what we have achieved in the past few months. In many ways, it bu