mysql insert if doesn t exist

Check the latest slow log and check whether slow log is enabled.   Mysql> show variables like '% slow % ';+ --------------------- + ------------------------------------------ + | Variable_name | Value | + --------------------- + ---------------------

Transferred from: http://blog.csdn.net/biangren/article/details/8010018Recently began to learn hibernate, looking at Li Gang's "Lightweight Java EE Enterprise application combat." For the first Hibernate program, I wrote down the example of the book

ERROR1146 (42S02): Table ERROR 1146 (42S02): Table Check the latest slow log and check whether slow log is enabled. Mysql> show variables like '% slow % ';+ --------------------- + ------------------------------------------ + | Variable_name |

In the process of developing database-related logic, we often check to see if such a record exists in the table, if there is an update or no action, and if there is no record, a new record is inserted.This logic can be done with two SQL

Yesterday, a friend of the company used a MySQL instance to open Binlog, but in the process of booting failed (he did not mention, why failed), after the boot failed, he deleted the Ibdata1 and Ib_logfile, later, can normally start, but all the

18.2.1 MySQL server has gone away errors related to Lost connection to server during query. The most common cause of the MySQL server has gone away error is that the server times out and closes the connection. By default, if nothing happens, the

Detailed description of Mysql commands (recommended) and mysql commands This section describes commonly used MySQL commands, including connecting to the database, changing the password, managing users, operating databases, operating data tables, and

Install mysql in centos5.8 1. Install mysql yum Source Download the rpminstallation package of mysql's latest yumsource from http://dev.mysql.com/downloads/repo/yum/   wget http://repo.mysql.com//mysql57-community-release-el6-9.noarch.rpm Use yum

Mysql commands are often used by everyone, but few of you can sort them out. there are not many projects recently. you can take a moment to summarize the mysql database commands. if you need them, refer to section 1. connect to Mysql. Format:

1, connect MySQL Format: mysql-h host address-u user name-P user Password 1, connected to the MySQL on the computer. First open the DOS window, and then enter the directory Mysql\bin, and then type the command Mysql-u root-p, enter after the