mysql library

First, the system databaseINFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information,

I. Introduction of the Database1, the origin of the databaseWhat we've learned before is that data is stored in a file for permanent preservation, and there is no doubt that a file can only exist on a single machine, which poses many problems:(1)

The first way:1. Stop MySQL Services first: Service mysqld stop2. Add parameter start Mysql:/usr/bin/mysqld_safe--skip-grant-tables &Then you can access MySQL without any restrictions.3.root User Login system: Mysql-u root-p MySQL4. Switch database:

1. Access to the INFORMATION_SCHEMA database (information on other databases)Use INFORMATION_SCHEMA;2, query the size of all data:Select Concat (Round (sum (data_length/1024/1024), 2), ' MB ') as data from tables;3. View the size of the specified

1. Search for booksA. Requests can be made on the category, title, publisher, year (year range), author, price (interval). Each book information includes the following:(ISBN, category, title, publishing house, year, author, Price, total collection,

Add database administrator data and user datait's rather boring. Use Java to stitch up SQL statements and write to the databasejust put it on the attachment and upload it.Sixth Administrator and user login verification1, verification code.

Ask php about the mysql database layout. There are two people in each of the following groups: one person in the left and right areas, and then infinitely extend. How can each member count the total number of members in the left and right zones?

Recently in the laboratory equipment management system, before using the SQLite database, because it is the network version, replaced MySQL database, a large number of data manually knocked into too slow, there is no way to import it?Here I did not

I. Introduction to the LibraryINFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information and so on

I. Introduction to the LibraryINFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information and so on

First, the system database INFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information, etc.

1. View all library sizes under the DB instance, and the result is in megabytesSelectTable_schema,sum(data_length)/1024x768/1024x768 asData_length,sum(index_length)/1024x768/1024x768 asIndex_length,sum(Data_length+Index_length)/1024x768/1024x768

SHOW DATABASES //Lists the MySQL Server database. SHOW TABLES [from db_name] //Lists database data tables. SHOW CREATE TABLES tbl_name //Export data table structure. SHOW table

Copying MySQL Databases to another machineIn cases where you need to transfer databases between different architectures, you can use mysqldump To create a file containing SQL statements. can then transfer the "file to the" and "the" and feed it as

#!/usr/bin/pythonImport Os,sys,pymysqlMysqlbase = '/usr/local/mysql/bin/'If Len (sys.argv) = = 1:Print (' Format:python + script_name + user + password + IP ')Elif sys.argv[1] = = '-h ':Print (' Format:python + script_name + user + password + IP

The first query looks at how many tables, table names, etc. in the librarySELECT * FROM INFORMATION_SCHEMA. TABLESInformation_schema This data sheet holds information about all databases in the MySQL server. such as database name, database table,

We know that session is a conversational technology that enables you to share data across scripts or to detect user status.How the session works (1) When a session is first enabled, a unique identifier is stored in a local cookie. (2) First, using

Use INFORMATION_SCHEMA;To query the size of all data:Select Concat (Round (sum (data_length/1024/1024), 2), ' MB ') as data from tables;To view the size of the specified database:Select Concat (Round (sum (data_length/1024/1024), 2), ' MB ') as data

Not long ago, there was a small question about MySQL's lower_case_table_names parameters:1.lower_case_table_names is the table name ignoring case or all objects (fields, indexes, etc.) ignored?2. Case-sensitive table (with uppercase, lowercase)

A system database Two database operations Three-Name specification Four user rights Five. Change the password Six forgot Password Seven Chinese garbled problem I. System database INFORMATION_SCHEMA: Virtual