MySQL

The code is as follows Copy Code $con = mysql_connect ("localhost", "root", "222222");if (! $con){Die (' Could not connect: '. Mysql_error ());}echo "Success"Mysql_close ($con); Close connectionVar_dump ($row); Print outPrint_r ();

1.IFNULL statement: Ifnull (EXP1, EXP2), return EXP2 if EXP1 is null, return EXP1 if not null The code is as follows Copy Code mysql> SELECT ifnull (null, 100);+-------------------+| Ifnull (NULL, 100) |+---------------

The first two days when you encountered data recovering data with the source command, the prompt package was too big an error. That package Mymanager exported, this time with MySQL with the Mysqldump tool successfully exported and imported into the

mysq Index Type: normal index, unique index and primary index 1. General Index The only task for a normal index (indexed by the keyword Key or index) is to speed access to the data. Therefore, only those that appear most frequently in the query

First, the MySQL user's basic description: 1.1 Basic structure of the userUsers of MySQL: User name @ host Username: within 16 charactersHost: Can be host name, IP address, network address, etc.Host Name: Www.111cn.net,localhost ip:192.168.0.1

Mysql> show Processlist; +-–+ ————-+ —————— –+ | Id | User | Host | db | Command | time| State | Info +-–+ ————-+ —————— –+ |207|root |192.168.0.2:51621 |mytest | Sleep | 5 | | Null |208|root |192.168.0.2:51622 |mytest | Sleep | 5 | | Null |220

MySQL is divided into two roles 1, master server Master 2, from the server slave MySQL master-slave replication is the database synchronization between two servers, can also be understood as a backup of the primary server, when the master server

Solution 1: Open Task Manager-service-mysql** to see if its status has started, such as not started, right after the start, re-open the MySQL command line Client, restart MySQL. Solution 2: The host file (the host file in the

Mydumper Installation 1, first install CMake, because this software to use CMake compile The code is as follows Copy Code # Apt-get Install CMake 2, the next installation Mydumper compatibility package, this

Note: This document has two MySQL instances, multiple instance methods and so on Linux operating system: centOS6.3 64bit (Installation of the system default development package) Example one: MySQL version: mysql-5.0.56

A unibilling machine suddenly loads heavier a few days ago. The CPU is found to be heavily occupied in top. The AGI program runs slowly, and a zombie process occurs. In fact, there were only about 50 concurrent calls. Far from the normal level. The

Single-table MySQL UPDATE statement: 　 The code is as follows Copy Code UPDATE [low_priority] [IGNORE] Tbl_nameSET col_name1=expr1 [, col_name2=expr2 ...][WHERE Where_definition][Order BY ...][LIMIT Row_count]Update

The code is as follows Copy Code SELECT * FROM Test_infointo outfile '/tmp/test.csv 'Fields terminated by ', ' optionally enclosed by ' "' escaped by '" 'Lines terminated by ' RN '; To import CSV format data in MySQL:

MySQL tutorial cycle and conditional judgment SQL query Writing, we all know that only the MySQL 5 after the stored procedures, these usages, then we want in the SQL with if else while these, we have to use the stored procedure or function to

MySQL Tutorial Create a database tutorial, delete a database instance CREATE DATABASE ;Mysql>Mysql>mysql> CREATE DATABASE myDatabase;Query OK, 1 row affected (0.03 sec) Mysql>mysql> drop Database myDatabase;Query OK, 0 rows affected (0.01 sec)

In MySql4.0.12, with the "CREATE TABLE Bak_name as SELECT * from Original_name" statement , the generated Bak table does not have a primary key and the index, the use of the time to pay attention to. You can build a table structure that you want to

The Date_add () function adds the specified time interval to the date. GrammarDate_add (Date,interval expr type) The date argument is a valid datetime expression. The expr parameter is the time interval that you want to add. The type parameter can

Workaround One: To other MySQL-installed servers (if you want to know the MySQL root password on the server), open the "MySQL installation directory/var/mysql tutorial," which will be the user.frm, user. MyD, user. Myi three files are copied to the

These statements create a stored subroutine. To create a subroutine in MySQL 5.1, you must have the Create routine permission, and alter routine and execute permissions are automatically granted to its creator. If binary logging is allowed, you may

MySQL tutorial is null usage Note that in MySQL, 0 or null means false and other values mean true. The default truth value of a Boolean operation is 1. The special handling of NULL is in the previous section, in order to determine which animal is