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Overview?? mysql5.5 before the default storage engine is myisam,5.5, InnoDB is changed. To modify the default engine, you can modify the configuration file in the default-storage-engine . You can show engines view the engines that are supported by

Select Purpose: Removes the specified column's data from the specified table Grammar: SELECT column_name (s) from table_name Explain: Select a row from the database and allow one or more columns or rows to be selected from one or more tables.

The main contents of this chapter: First, foreign key Second, table connection Third, sub-query Iv. Index First, FOREIGN key: 1. What is a foreign key 2. Foreign KEY syntax 3, FOREIGN key conditions 4.

MySQL database Advanced (i)--data integrity first, data integrity Introduction 1, Data integrity IntroductionData redundancy refers to the existence of some duplicate data in the database, data integrity refers to the data in the database can

After MySQL version 3.23.44, the InnoDB Engine type table supports foreign KEY constraints.Use conditions for foreign keys:1. Two tables must be a InnoDB table, the MyISAM table temporarily does not support foreign keys (it is said that later

http://blog.csdn.net/xiaoyu714543065/article/details/8211265A transaction has four characteristics: atomicity (atomicity), consistency (consistency), isolation (isolation), and persistence (durability). These four properties are referred to as ACID

MySQL Search engine SummaryAfter mysql5.5, MySQL uses the InnoDB storage engine by default.To modify the default engine, you can modify the default-storage-enginein the configuration file. Can be through show variables like ' default_storage_engine '

　　There is a concept of storage engine in MySQL and the optimal storage engine can be selected for different storage requirements.I. OverviewMySQL 5.0 supports storage engines including MyISAM, InnoDB, BDB, Memory, MERGE, EXAMPLE, NDB Cluster,

by Joe Celko,2013/09/18 (first published: 2010/05/25)The seriesThis article is part of the stair series: stair-to-database designNew tasks for designing and creating databases? Joe Celko is one of the most widely read writers on SQL, explaining

MySQL has a variety of storage engines, each of which has its own advantages and disadvantages, and can be chosen with merit:MyISAM, InnoDB, MERGE, MEMORY (HEAP), BDB (BerkeleyDB), EXAMPLE, Federated, ARCHIVE, CSV, Blackhole.MySQL's storage engine

After MySQL version 3.23.44, the InnoDB Engine type table supports foreign KEY constraints.Use conditions for foreign keys:1. Two tables must be a InnoDB table, the MyISAM table temporarily does not support foreign keys (it is said that later

Review MySQL CREATE TABLE statement users (ID integer/name string/birthday date type, default today)Drop table if exists users;CREATE table if not EXISTS users (ID int (5) Auto_increment primary KEY,Name varchar (4) is not NULL,Birthday date default

First, FOREIGN KEY constraintsMySQL uses foreign key constraints to ensure the integrity and accuracy of data between tables.Use conditions for foreign keys:1. Two tables must be a InnoDB table, the MyISAM table temporarily does not support foreign

为已经添加好的数据表添加外键:语法:alter table 表名 add constraint FK_ID foreign key(你的外键字段名) REFERENCES 外表表名(对应的表的主键字段名);例: alter table tb_active add constraint FK_ID foreign key(user_id) REFERENCES tb_user(id)//FK_ID是外键的名称/*CREATE TABLE `tb_active` ( `id` int(11)

First, the Engine foundation1 Viewing system-supported storage engines　　Show engines;2 View the storage engine used by the table in two ways:A, Show table status from database_name where name= ' table_name ';b, show create TABLE table_name;To view

Reprinted from: Http://www.cppblog.com/wolf/articles/69089.html#PostThe original text is too incisive and image, can't help reprint came to leave notes, like the author saluteAfter MySQL version 3.23.44, the InnoDB Engine type table supports foreign

One. Common MySQL command-line commands1. Start MySQL service net start MySQLStop MySQL service net stop MySQL 2. Netstat–na | findstr 3306 View the port being monitored, findstr is used to find out if there is a port in the back3. Log in to the

First, what is the foreign key in MySQL (froeign key)If there are two tables, one of the table's fields points to the primary key of the other table, which can be called the foreign key (Froeign key).When you add a record to a child table, you need

Summarize three kinds of MySQL foreign key constraint modeIf Table A's primary key is a field in table B, the field is called the Foreign key of Table B, table A is called the primary table, and table B is called from the table. Foreign keys are

1. mysql Common commandsCreate database name; Create a databaseUse DatabaseName; Select DatabaseDrop database name deletes databases directly and does not alertShow tables; Show TableDescribe TableName; Detailed description of the tableSELECT * FROM