MySQL

1. View MySQL size Use Database Name Select sum (data_length) + sum (index_length) From information_schema.tables where table_schema = 'database name '; The result is in bytes, except 1024 for K and 1048576 for m. -------------------------------

After MySQL is installed for the first time, an error occurs when the connection is established through ODBC. The same error is reported when the connection string is configured through the program. The reason is that the password set during

Step 1: Download the MySQL driver package Official is http://dev.mysql.com/downloads/connector/net Step 2: Introduce Components The downloaded file is a compressed file that is decompressed to a local disk. Find the mysql. Data. dll file in the bin

Table 1: Numeric column type The names and value ranges of each numeric type are shown in table 2. Type description Value Range Tinyint [(m)] Signed value:-128 to 127 (-27 to 27-1)Unsigned value: 0 to 255 (0 to 28-1)

Add a user first (but also use the root user)   Format: grant permission on database name. Table name user @ login host identified by "User Password ";Grant select, update, insert, delete on *. * To zhxia @ '%' identified by '123 '; Or all

This indicates that the connected user account does not have the permission for remote connection and can only log on to the Local Machine (localhost. Solution: First, log on to the MySQL server by following the steps below To log on to MySQL,

During the maintenance of the company's CRM today, a large MySQL database was restored and the recovery failed. Use the following method (navicat is used for MySQL management). Set the values of the following parameters and the following statements

From: http://www.51testing.com/html/96/110296-69546.html The output result of the processlist command shows which threads are running. This command can be used to identify problematic query statements. Enter mysqladmin processlist In the MySQL/bin

Before mysqlcheck is unknown, I moved the database on one server to another server and wanted to see which table was damaged. I didn't want to execute it one by one on the command line, the following is my script #! /Bin/bashPass = "123456" #

An alarm is reported today. The alarm information is: MYSQL_BIN_LOG::purge_logs was called with file '/home/log/mysql-bin.22.log' not listed in the index Google one and found the MySQL source code:View code int MYSQL_BIN_LOG::purge_logs(const char *

MySQL memory table so that we often use, but MySQL memory table is not a universal tool to improve read performance, in some cases, MySQL memory table may be slower than the actual table Type of B-TREE. Create Table 'mem _ test '( 'Id' int (10)

To import all the data stored in the SQL Server database to the MySQL database, collect related information on the Internet, and find two methods. Now let's talk about them separately. The first method is to install MySQL ODBC and use the export

1.Use the mysql_connect () function to connect to the MySQL server: mysql_connect ("hostname", "username", "password ");For example, $ link = mysql_connect ("localhost", "root", "911") or die ("cannot connect to the database server! The database

When using MySQL, you sometimes need to query records with unique fields. Although MySQL provides the keyword distinct to filter out redundant duplicate records, only one record is retained, but it is often used to return the number of records that

Document directory 2. Create an index 4. delete an index 1. Indexing In addition to the ordered search mentioned above, the database can greatly improve the query efficiency by using various fast locating technologies. In particular, when the

Whether in a small free database space or a large e-commerce website, it is necessary to reasonably design the table structure and make full use of the space. This requires us to fully understand the Common Data Types of database systems. Next I

1. Only copy the table structure without copying data Select * into B from a where 1 <> 1;   2. Table data migration table B already exists: Insert into B (d, e, f) Select a, B, c from; Table B originally does not exist: Create Table B (select

From: http://parand.com/say/index.php/2009/09/01/finding-and-fixing-slow-mysql-queries/bar.html Edit the my. CNF or my. ini file and remove the comments of the following lines of code: log_slow_queries =

In a web application system, if the database has a performance bottleneck and you are using a MySQL database, you can consider using a database cluster to achieve query load. Generally, database query operations in any system are more than update

1. Create a database: Create Database db_name; Database deletion: drop database db_name; When deleting a database, you can first determine whether it exists and write it as: drop database if exits db_name 2. Create a table: Create Table table_name (