Mysql Delete Query Example

mysql tutorial to modify the table / field to add / delete table index create table test (blob_col blob, index (blob_col (10))); In mysql 5.1, myisam and innodb table prefix can reach 1000 bytes long. Note that the prefix limit should be measured in bytes, while the prefix length in the create table statement is interpreted as the number of characters. Must be considered when specifying the prefix length for columns that use multi-byte character sets. ...

Here's an excerpt of the background, followed by a record of the operations I migrated from MySQL 5.5.31 to mariadb 5.5.31 on CentOS 6.4. 　　Finally, I found a better way to migrate. 1. Background introduction MySQL is the world's most popular open source relational database. 2008, Sun acquired MySQL. Then, in 2010, Oracle bought Sun, and MySQL fell into Oracle's hands. Oracl ...

As long as you master the following method, you can basically get the mysql database. First, the connection MYSQL format: mysql-h host address-u username-p user password 1, Example 1: Connect to the local MySQL: First open the DOS window and then enter the directory mysqlbin, then type the command mysql -uroot - p, after the carriage return prompts you to lose the password, if you just installed MYSQL, super user root is no password, so enter directly into MYSQL, MYS ...

When it comes to big data, it has to do with Alibaba. The world's leading E-commerce enterprise, the amount of data processed every day is unmatched by any other company, it is also transforming into a real data company--mysql is an important weapon in the transformation of Alibaba. 　　A database architect who interviewed Ali, who believes Ali has the best performance of open source MySQL, beyond any relational database and NoSQL. In the 2009, Oracle acquired the copyright of MySQL by acquiring Sun, and the industry began to question the use of Oracle ...

The initial key value comparison, MongoDB victory faster, and this has always been our goal to give the database system MySQL dragster the speed of the disk as its biggest obstacle, this really can make sense? Let's just make an obstacle, what about the solution? If an obstacle limits your dragster, you can choose to bypass it faster or improve on the computer. For example: Avoid the use of disk, as much as possible memory in lieu of faster disk (such as SSD) in fact, this is not good analogy, because the limit from the disk is like ...

Method 1 delete yourtable where [id] not in (select max ([id]) from yourtable group by (name + value) b on a.id = b.id where b.id ...

Mysql Guide sql distinct delete duplicate records How to use distinct keyword in mysql Filter the result list in a select statement Duplicate value If you want to delete duplicate data query data, you can use the distinct keyword to filter duplicate values, the following distinct usage. select distinct column_name from table_name; Let's take a look at a simple example ...

Operation database is the basis of dynamic Web programming, this article gives you a detailed description of how PHP operates MySQL database 1. Establish and close connection 1 mysql_connect () resource mysql_connect ([string hostname [:p ort][:/path/to/socket][,string username] [, String Passwor ...

History of the most complete MySQL backup method, you need friends can refer to the next. I have used the backup methods are: mysqldump, mysqlhotcopy, BACKUP TABLE, SELECT INTO OUTFILE, or backup binary log (binlog), can also be directly copied data files and related configuration files. MyISAM table is saved as a file, it is relatively easy to back up, several methods mentioned above can be used. Innodb all the tables are ...

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 ...