mysql select last record in each group

Method for obtaining the last record of each userid In the MySQL table, mysqluserid See the following table: CREATE TABLE `t1` (`userid` int(11) DEFAULT NULL,`atime` datetime DEFAULT NULL,KEY `idx_userid` (`userid`)) ENGINE=InnoDB DEFAULT

MySQL group query for data Tables (group by)The GROUP BY keyword can group query results by a field or multiple fields. The values in the field are equal to one group. The basic syntax format is as follows:GROUP by property name [having conditional

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PHP MySQL database common cmd command setshow databases; Display DatabaseCreate database name; Create a databaseUse DatabaseName; Select DatabaseDrop database name deletes databases directly and does not alertShow tables; Show TableDescribe

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 Format statement specificationHow do I log into your database?Example!If you are compiling the installation of the flowers, then you have to compile the installation of the directory to go, my is installed into the/usr/local/mysql database: Cd/

Concrete Example 1. PHP Server ComponentsFor beginners, it is recommended to use the integrated server component, which already includes PHP, Apache, Mysql and other services, eliminating the time spent by developers in the tedious configuration

MySQL entry, mysql entry classic This chapter describes the Relational Database Management System (RDBMS) of MySQL and the Structured Query Language (SQL) used by MySQL ). The basic terms and concepts that should be mastered are listed, and the

1. Export the entire database Mysqldump-u user name-p--default-character-set=latin1 Database name > exported file name (database default encoding is latin1) Mysqldump-u wcnc-p SMGP_APPS_WCNC > Wcnc.sql 2. Export a table Mysqldump-u user name-P

Use of Replace and regexp0 Comments | This entry is posted on APR 08 2010 MySQL Replace usage 1.replace into Replace into table (Id,name) VALUES (' 1′, ' AA '), (' 2′, ' BB ') The purpose of this statement is to insert two records into table tables.