MySQL

1. If the field of 2 tables is consistent and you want to insert all the data, you can Use this method: INSERT into target table SELECT * from source table; Example: INSERT INTO t_a select * from T_b; 2. If you want to import only the specified

Types and pros and cons of MySQL indexesAn index is a special kind of file (an index on a InnoDB data table is an integral part of a table space), and they contain reference pointers to all records in the datasheet.Note: [1] The index is not

DirectoryPreface: What is JDBCI. Preparatory work (i): MySQL installation configuration and basic LearningIi. preparatory Work (ii): Download the jar package for the database and import itThird, JDBC Basic operation(1) Define the class of the record

Original: 10 minutes learn to understand and solve MySQL garbled problem Before reading this article, it is strongly recommended that the concept of character set encoding is still more vague for students to read the following blog before

MySQL Master sync configuration Step reprint: http://www.jb51.net/article/33624.htm Create a sync user, modify the/ETC/MY.CNF profile, add the following to it, restart the server odd even MySQL service respectivelyMySQL Master Master sync

1.mysql_sqlstateconst char *mysql_sqlstate (MySQL *mysql)DescribeReturns a null-terminated string that contains the SQLSTATE error code for the last error. The error code consists of 5 characters. ' 00000 ' means no error. Its value is specified by

The MySQL default mode of operation is autocommit auto-commit mode. This means that unless a transaction is explicitly started, each query is executed automatically as a separate transaction. We can change whether the autocommit mode is

There was a small problem connecting to the MySQL database on Ubuntu today.Can ' t connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock ' (2)The first use can also be used, suddenly it is not good, do not know whether it is not

Every once in a while there will be an article about the database performance description of the hype, often appear 50W qps,100w QPS such large numbers, minus thousands of words to explain, the core content is a top-level configuration of the server

We use the current my-sql to compare the new version of my SQL 5.0 version. First, how to get my SQL 5.0 we can download from the Internet ([Url]www.mysql.cn[/url]).Let's look at how to install my SQL to support multiple platforms, that is, it can

Show MySQL status every two seconds, showing 5 times.# mysqladmin-uroot-p-I 2-c 5 statusTo view the running status of MySQL:#mysqladmin-uroot-p PingMysqladmin Ver 8.42 distrib 5.1.73, for Redhat-linux-gnu on x86_64Copyright (c) and/or, Oracle, its

#要修改的变量DECLARE var_id VARCHAR (+) DEFAULT ';#需要修改的数据的数量DECLARE Var_updatecount INT;#当前循环次数DECLARE Var_whiletimes INT;#定义游标DECLARE Var_cur CURSOR forSELECT ID from table_name;#打开游标OPEN var_cur;#将游标的数据进行赋值FETCH var_cur into var_id;#获取循环次数SELECT COUNT (

The slow query log is used to optimize the query statement, the following are several parameters, 5.5 can be later to the subtle (MS)Mysql> Show variables like '%slow% ';+---------------------------+-------------------------------+| variable_name |

Because after a company's project, you have to use MySQL, special to learn!One. mysql InstallationBaidu MySQL download one can. just take a look at some important data:The first one is Port number:3306. Port number default 3306, generally do not

MySQL Date time function encyclopedia1. DAYOFWEEK (date)The return date is the day of the week (1= Sunday, 2 = Monday,...... 7= Saturday, ODBC Standard)Mysql> Select DAYOFWEEK (' 1998-02-03 ');32. WEEKDAY (date)The return date is the day of the week

ERROR 1130:host ***.***.***.*** isn't allowed to connect to this MySQL serverIndicates that the connected user account does not have remote connection permissions and can only log on natively (localhost). You need to change the host entry in the

First: Create a new batch file Backup.datThe code is as follows:net stop MySQLxcopy "C:/Program files/mysql/mysql Server 5.0/data/piaoyi/*.*" d:/db_backup/%date:~0,10%//ynet start MySQLNote: There are spaces in the path in the batch command, you

Summary of SQL statements for common MySql operations and MySql SQL statements Common MySQL operations are summarized here, which has been integrated into the code and proven to be correct.Copy codeThe Code is as follows:/* Create a database

MySQL server connection process analysis, mysql Server Analysis Mysqld is the master process on the MySQL server. It can be said that mysqld is the real core of MySQL, and all work is carried out around the mysqld process. Therefore, mysqld code is

In Linux, Mysql is mutually active/standby.  System Environment: CentOS 6.5 Master1: 192.168.100.204 Master2: 192.168.100.205 Mysql version: mysql-5.6.19 Note: The configuration methods for versions earlier than mysql 5.5 and later are