MySQL

Error message: Java.io.IOException:java.sql.BatchUpdateException:Incorrect string value: ' \xd6\xd0\xb9\xfa\xb9\xa4 ... ' for column ' Content ' at row 1 At Org.apache.gora.sql.store.SqlStore.flush (sqlstore.java:340) At Org.apache.gora.sql.store.

Wildcard characters in a like statement in MySQL: percent, underline, and escape % represents any number of characters SQL code http://blog.csdn.net/yc7369/ SELECT * from user where username like '%huxiao '; SELECT * from user where username

On Weibo to discuss MySQL in the Delete large table Engine=innodb (30g+), how to reduce the time of MySQL hang, now do a simple summary: (microblogging address: Http://weibo.com/1642466057/yuPz2guYJ) When the Buffer_pool is very large (30g+),

Today we are going to introduce the Pt-stalk tools in Percona. Some problems occur intermittently, monitoring information may not be too late to collect information, MySQL locks or activities peak usually does not leave any data to analyze. This is

Master-Slave Replication latency Monitoring, my previous practice was to compare the difference (read_master_log_pos,exec_master_log_pos) of the two variables in show slave status\g, setting the difference to a range that you think is reasonable,

Environment: navicatfor MySQL 8.2 + mysql Sever 5.1 Problem: Through the Mysql command line can not connect, enter a password after no response, after a period of time system beep, command Line window flashed, and through the navicat for Mysql 8.2

The log files described here are files of the MySQL database itself, regardless of what storage engine is specifically used. Error log MySQL's error log is similar to Oracle's Alert.log, which ends with. Err by default, and the DBA should first

View table hint 1030 error in MySQL: mysql> desc User; Error 1030 (HY000): Got error from storage engine The cause of this error is insufficient disk space, resulting in a lack of temporary directory space for MySQL tmpdir. The solution is to

Phenomenon Import MySQL mysqldump file times wrong, prompt error 2013 (HY000) at line xxoo:lost connection to MySQL serverduring query, import operation interrupted exit. Reason The values for inserts in the mysqldump file to import are too many,

Nginx was developed by Igor Sysoev, the second rambler.ru site for Russian traffic, which has run over 2.5 at the site. Igor releases the source code in the form of a BSD-like license. Nginx has been known for its stability, rich feature sets,

TINYINT -128-127 TINYINT UNSIGNED 0-255 SMALLINT -32768-32767 SMALLINT UNSIGNED 0-65535 Mediumint -8388608-8388607 Mediumint UNSIGNED 0-16777215 INT or INTEGER -2147483648-2147483647 INT UNSIGNED or INTEGER UNSIGNED 0-4294967295

Whether in a small, free database space or a large e-commerce site, a reasonable design of the table structure, the full use of space is very necessary. This requires us to have a good understanding of the common data types of database systems.

1, look at the machine configuration, refers to three piece: CPU, memory, hard disk 2, look at the MySQL configuration parameters 3, check the MySQL line state, you can use the Mysqlreport tool to view 4, view the MySQL slow query After solving

When MySQL is first installed on the machine, you can access the database anonymously or as root without a password. Also, if you are an administrator, you need to build and authorize some users, which involves setting up a password. Here's how to

#!/bin/bashlog=/diskb/mysql/slowlog/#定义日志存储路径Date= ' date + '%y-%m-%d ' #定义时间参数User=root #填写MySQL账户信息passwd=123456MYSQL-U$USER-P$PASSWD-E "Set global slow_query_log=0" #停止mysql慢查询日志MYSQL-U$USER-P$PASSWD-E "Set global slow_query_log_file= '

Database operations:Create a database, create a table--createDelete a database, delete a table--dropDelete table contents--truncate, delete (the latter is inefficient, one row to delete records)Query database, query table--selectInserting, updating,

First download the MySQL Jar package website: http://dev.mysql.com/downloads/connector/j/Execute SQL statement to build the database to add test data, here do not do too much introduction, are basic knowledge; don't forget to change the code to UTF-8

1. UNIX timestamp converted to date function: From_unixtime ()[SQL]View PlainCopy Select From_unixtime (1156219870); Output: 2006-08-22 12:11:102. Date conversion to UNIX timestamp function: Unix_timestamp ()[SQL]View PlainCopy

Query statement:SelectStudent.stu_name,Max(Score. Number) fromStudentInner JoinScore onstudent.stu_id=score.student_idInner JoinCourse onscore.course_id=course.cou_idInner JoinTeacher

The difference between IN and exists IN SQL statements and the application of inexists IN SQL statementsTable display First, the query involves two tables, one user and one order table. The specific table content is as follows: User