How To Use If Else In Mysql Query

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Mysql increase the index of the three principles

First, the importance of the index The index is used to quickly find a column in a particular value of the line. Instead of using an index, MySQL must start with the first record and then read the entire table until it finds the relevant row. The larger the table, the more time it takes. If the table in the query column index, MySQL can quickly reach a location to search the middle of the data file, there is no need to see all the data. Note that if you need to access most of the rows, sequential reads are much faster since we avoid disk searches. If you use Xinhua Dictionary to find "Zhang" the Chinese characters, do not use the directory, then ...

PHP operation MySQL 3rd pass the next day

In this lesson, we're going to do some more complicated work to show the data in multiple rows, the database exchanging data one, the while loop in this lesson, we will continue to drill down and use PHP and MySQL to write some simple and useful pages.   We start with the database we created yesterday and display the data in the library, but we'll touch it a little bit. First, we use the following code to query the contents of the database. <html> <body> <?php $db = Mys ...

php connect mysql database operation class

This is a relatively full mysql operation Oh, yesterday wrote a simple link mysql database code, relative to this, that is the easiest, this is a data query, update, delete, and other operations . * / class mysql {private $ db_host; // database host private $ db_user; / / database user name private $ db_p ...

PHP operation MySQL 3rd pass the third day

In this lesson, we want to learn how to increase the intelligent processing capacity of the Web page. Basic functions Welcome to the third and final lesson of this tutorial. If you've learned the first and second lessons, you've mastered the basics of installing and programming MySQL and PHP. Here are some of the other functions of PHP that might be useful to you and make your development process simpler.   First, let's look at the document. You should know some basic concepts of the header file, right? The header file is an external file whose contents are included in the main program. ...

php tutorial registration page code (mysql tutorial + php)

This is a use mysql php instance user registration code, is relatively simple, is to submit the html data submitted to the mysql database tutorial. * / include ('global.php'); if ($ _ post ['sub']) {$ user = $ _post ['username']; $ pwd = md5 ($ _ post ['p ...

A solution that uses MySQL rand () in PHP to take a random record of CPU 100%

MySQL database has 10 tens of thousands of data, using rand () to extract a random 10 records, resulting in high server CPU consumption until the crash ~ Baidu has consulted some information, and then combined with some of their own experience, the following solutions: $idlist = '; For ($i =1 $i <=20; $i + +) {if ($i ==1) {$idlist =mt_rand (3,25216);} else{$idlist = $idlist.

PHP Beginners Basics (10)

PHP connection MySQL database 10.   PHP's biggest feature is the ability to manipulate the database is particularly powerful, PHP provides a variety of database support. With PHP you can easily connect to the database, request the data and display it in your Web site, or even modify the data in the database. In this section we mainly in the Internet with PHP to use most of the MySQL database as an example, to introduce the relevant MySQL database operation functions and database basic operation and other aspects of knowledge. In the MySQL database, ...

Data import HBase Three most commonly used methods and practice analysis

To use Hadoop, data consolidation is critical and hbase is widely used. In general, you need to transfer data from existing types of databases or data files to HBase for different scenario patterns. The common approach is to use the Put method in the HBase API, to use the HBase Bulk Load tool, and to use a custom mapreduce job. The book "HBase Administration Cookbook" has a detailed description of these three ways, by Imp ...

Open source Cloud Computing Technology Series (iv) (Cloudera experience)

Cloudera's location is bringing big Data to the Enterprise with Hadoop Cloudera in order to standardize the configuration of Hadoop, you can help the enterprise install, configure, Run Hadoop to achieve large-scale enterprise data processing and analysis. Since it is for enterprise use, Cloudera's software configuration is not to use the latest Hadoop 0.20, but the use of Hadoop 0.18.3-12.clou ...

Construction of enterprise security building open source SIEM platform (in)

Construction of enterprise security building open source SIEM platform. SIEM (security information and event management), as its name implies, is a management system for security information and events. It is not a cheap security system for most enterprises. This article uses the author's experience to introduce how to use open source software to analyze data offline and use attack modeling Way to identify attacks. Review the system architecture to the database, for example, through logstash to collect mysql query log, near real-time backup ...

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