mysql update each row

In some cases we need to update the status of a record in the datasheet and then take it out, but if you don't have a primary key to confirm the unique record before the update, there's no way to know which record is being updated.To illustrate the

A lock is a mechanism by which a computer coordinates multiple processes or a purely thread concurrently accessing a resource. in a database, data is a resource that is shared by many users in addition to the contention of traditional computing

MySQL row-level lock, table-level lock, page-level lock details page-level: engine BDB. Table-level: engine MyISAM, which is interpreted as locking the entire table and reading at the same time. Row-level: engine INNODB, locking a single row of

MySQL performance tuning and Architecture Design-Chapter 1 Performance Design-MySQL Replication and replication Optimization Chapter 1 scalability design-MySQL Replication Preface: MySQL Replication is a unique feature of MySQL. It can completely

MySQL row-level locks, table-level locks, page-level locks, mysql details Page Level: Engine BDB. Table-level: Engine MyISAM, which is interpreted as locking the entire table. It can be read at the same time but cannot be written at the row level.

Objective In order to ensure consistent integrity of data, there is a locking mechanism in any database. The quality of locking mechanism should be directly thought of the concurrent processing ability and performance of a database system, so the

MySQL常用指令，java，php程序员，数据库工程师必备。程序员小冰常用资料整理MySQL common commands (for reference)The most common display commands are:1. Display the list of databases.show databases;2. Display the data table in the library:Use MySQL;Show tables;3, display the

Page Level: Engine BDB.Table-level: Engine MyISAM, which is interpreted as locking the entire table and reading at the same time.Row-level: Engine INNODB, locking a single row of records At the table level, the entire table is locked directly.

1.MySQL Engine Overview 1.1 What is a storage engineWhen we record a video file, it can be converted to different formats such as mp4,avi,wmv, and on the computer's disk will also exist in different types of file system Windows common Ntfs,fat32,

Henan College of Traditional Chinese Medicine Course Design Report of MySQL Database Management  Title: Research and Implementation of MySQL Clusters       Completion date:2012January 1, December 31   Contents 1. Course Design overview 3 2. research