Multiple Primary Key Mysql

This paper introduces how to build a network database application method by MySQL of the golden combination of Web database, PHP is a server-side embedded hypertext Processing language similar to Microsoft ASP, it is a powerful tool to build dynamic website. While MySQL is a lightweight SQL database server that runs on a variety of platforms, including Windows NT and Linux, and has a GPL version, MySQL is considered the best product for building a database-driven dynamic Web site. PHP, MySQL, and Apache are Linux ...

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 ...

MySQL optimization is very important. The most common and most needed optimization is limit. 　　The limit of MySQL brings great convenience to paging, but when the amount of data is large, the performance of limit is reduced dramatically. The same is 10 data select * FROM Yanxue8_visit limit 10000,10 and select * from Yanxue8_visit limit 0,10 is not a quantitative level ...

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. ...

Pagerduty, an emerging internet start-up, is a product that can send reminders on the server, including on-screen displays, phone calls, SMS notices, email announcements, and more. At present, AdMob, 37Signals, StackOverflow, Instagram and so on have adopted the pagerduty as the message notification as well as the sudden event processing tool. Doug Barth, author of this article, shared how Pagerduty successfully migrated existing system MySQL to the XTRADB cluster to ...

SQL used to manipulate the database is generally divided into two kinds, one is the query, which is what we call the SELECT statement, the other is to update the statement, also known as data manipulation statements. The implication is to modify the data. There are 3 statements in the standard SQL, which are INSERT, UPDATE, and DELETE. There is another REPLACE statement in MySQL, so this article uses MySQL as a background to discuss how to make updates in SQL. First, INSERT and REPLACE I ...

"Editor's note" WiX has been operating the site for a long time, and after the launch of the WYSIWYG web platform based on HTML5, users have established more than 54 million sites in the company, and most of these sites have less than 100 solar PV. Since the PV of each page is low, the traditional caching strategy does not apply. Even so, however, the company has done so with only 4 Web servers. Recently, WiX chief back-end engineer Aviran Mordo in "...

MySQL Chinese wrong order solution / * The method has been changed to the character set of the field gbk, and then the order by order can be used directly. For example, change "name char (10)" to "name char (10) binary" by adding the "binary" attribute to the field containing Chinese and setting it as binary. ". If you make ...

Usually speaking of foreign keys, we only mention "the purpose of the foreign key is to determine the referential integrity of the data." However, what foreign keys specifically include the actions and meanings? 1, set the outer chain: (1), create a foreign key through create table: see 2 lines of code is built in the table command: create table city (... key idx_fk_country_id (country_id), constrain ...

In MySQL, using the id field of the auto_increment type as the primary key of a table and using it as a foreign key to other tables to form a "master-slave table structure" is a common usage in database design. However, in the specific generation of id, our order of operations is generally: insert records in the main table, and then get the automatically generated id, based on it to insert the record from the table. There is a difficulty here, is inserted into the main table record, how to get it corresponds to the id. The usual practice is through "select max (id) from table ...