You already created a database after running your Code-First application the first time, but what about the second time onwards?? Will it create a new database every time you run the application? What about the production environment? How do you alter the database when you change your domain model? To handle these scenarios, you have to use one of the database initialization strategies.

There are four different database initialization strategies:

  1. CreateDatabaseIfNotExists: This is default initializer. As the name suggests, it will create the database if none exists as per the configuration. However, if you change the model class and then run the application with this initializer, then it will throw an exception.
  2. DropCreateDatabaseIfModelChanges: This initializer drops an existing database and creates a new database, if your model classes (entity classes) have been changed. So you don't have to worry about maintaining your database schema, when your model classes change.
  3. DropCreateDatabaseAlways: As the name suggests, this initializer drops an existing database every time you run the application, irrespective of whether your model classes have changed or not. This will be useful, when you want fresh database, every time you run the application, like while you are developing the application.
  4. Custom DB Initializer: You can also create your own custom initializer, if any of the above doesn't satisfy your requirements or you want to do some other process that initializes the database using the above initializer.

To use one of the above DB initialization strategies, you have to set the DB Initializer using Database class in Context class, as shown below:

Database Initialization Strategies in Code-First:的更多相关文章

  1. Entity Framework Code-First(17):Database Initialization Strategy

    Database Initialization Strategies in Code-First: You already created a database after running your ...

  2. Database Initialization Parameters for Oracle E-Business Suite Release 12 (文档 ID 396009.1)

    In This Document Section 1: Common Database Initialization Parameters For All Releases Section 2: Re ...

  3. Database Initialization Parameters for Oracle E-Business Suite Release 12

    In This Document Section 1: Common Database Initialization Parameters For All Releases Section 2: Re ...

  4. Entity Framework Code-First(6):Database Initialization

    Database Initialization: We have seen that Code First creates a database automatically in the Simple ...

  5. EntityFramework6.X 之 Database Initialization

    Database Initialization 下图是数据库初始化的工作流 EF为数据库初始化准备了多种策略: l  CreateDatabaseIfNotExists:这是默认的初始化策略 l  D ...

  6. What is the Database Initialization Parameter That is Associated to an ORA-32004 Error ?

    APPLIES TO: Oracle Database - Enterprise Edition - Version 9.2.0.1 to 11.2.0.3 [Release 9.2 to 11.2] ...

  7. java Class的Long id初始化 为0的问题android数据库操做出现的 android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed

    java的class中的Long类型变量调用默认的 构造函数new后会被初始化为0. 这句话大家可能感觉这么低级的事情还用你说? 我想说的是这个会产生的一个应用场景 和 避免方法 场景:db插入时候p ...

  8. Required field 'client_protocol' is unset! Struct:TOpenSessionReq(client_protocol:null, configuration:{use:database=default}) (state=08S01,code=0)

    sparksql 2.和hive2.1.1 由于sparksql中的hive-cli 等包的版本是1.2的需要自己下载,下载替换之后不报错,替换之前做好备份

  9. Entity Framework Code-First(20):Migration

    Migration in Code-First: Entity framework Code-First had different database initialization strategie ...

随机推荐

  1. VS 2013 未找到与约束contractname Microsoft.VisualStudio.Utilities.IContentTypeRegistryService...匹配的导出[vs故障]【转】

    未找到与约束 contractname Microsoft.VisualStudio.Utilities.IContentTypeRegistryService RequiredTypeIdentit ...

  2. spoj687 后缀数组重复次数最多的连续重复子串

    REPEATS - Repeats no tags  A string s is called an (k,l)-repeat if s is obtained by concatenating k& ...

  3. tomcat提示警告: An attempt was made to authenticate the locked user"tomcat"

    启动tomcat7之后,运行正常,但是运行一段时间就会提示以下警告: 十二月 04, 2013 5:10:15 下午 org.apache.catalina.realm.LockOutRealm au ...

  4. Ext-进度条

    1.progress使用 Ext.MessageBox.progress('请等待',msg:'读取数据中……'); 真实案例 tqbtnNews:function(){ var me = this; ...

  5. Python 字符串操作

    Python 字符串操作(string替换.删除.截取.复制.连接.比较.查找.包含.大小写转换.分割等) 去空格及特殊符号 s.strip() .lstrip() .rstrip(',') 复制字符 ...

  6. 下载Spring的jar包的方法

  7. 【poj2823】 Sliding Window

    http://poj.org/problem?id=2823 (题目链接) 题意 维护滑动窗口最大最小值. Solution sb单调队列 代码 // poj2823 #include<algo ...

  8. [Poi2000]公共串

    #include <iostream> #include <cstdio> #include <cmath> #include <algorithm> ...

  9. Codeforces Round #389 Div.2 A. Santa Claus and a Place in a Class

    time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standa ...

  10. AngularJs angular.uppercase、angular.lowercase、angular.fromJson、angular.toJson

    angular.uppercase 将指定的字符串转换成大写 格式:angular.uppercase(string); string:被转换成大写的字符串. 使用代码: var str = &quo ...