Database Initialization Strategies in Code-First:
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:
- 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.
- 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.
- 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.
- 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
- Entity Framework Code-First(17):Database Initialization Strategy
Database Initialization Strategies in Code-First: You already created a database after running your ...
- 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 ...
- 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 ...
- Entity Framework Code-First(6):Database Initialization
Database Initialization: We have seen that Code First creates a database automatically in the Simple ...
- 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 ...
- 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] ...
- 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 ...
- 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
- Entity Framework Code-First(20):Migration
Migration in Code-First: Entity framework Code-First had different database initialization strategie ...
随机推荐
- LRU设计
list是双向链表,map保存key对应到list中的迭代器的位置,list保存<key,value> class LRUCache{ public: LRUCache(int capac ...
- spoj705 后缀数组求不同子串的个数
http://www.spoj.com/problems/SUBST1/en/ 题目链接 SUBST1 - New Distinct Substrings no tags Given a stri ...
- git初体验(一)基础
一.window下的git安装 1.安装教程 网上教程一堆,我参考的是这个:Git_Windows 系统下Git安装图解 还有这个也不错 2.环境搭建: 在配置完成后,自动加载到系统环境变量中,如我的 ...
- HTML文本域属性设置
1.设置文本域的字体 <TEXTAREA STYLE="font-size:9pt;font-family:verdana;color:#333333">输入内容< ...
- 使用oracle utl_http包需要注意的事项
总结下几次使用utl_http包遇到的几个问题 关于utl_http包功能还是很强大的 可以通过他来捕捉网站页面的内容 或者调用一个url的接口完成某项功能 Eg: declare req UT ...
- Python 素数判断;以及默尼森数
1. 素数/质数 只能被2或者本身整除的正整数. 2. 默尼森数 P是素数且M也是素数,并且满足等式M=2^P-1,则称M为默尼森数. 编程小要求: 输出前5个默尼森数 1)最外层循环找素数 中间层循 ...
- mysql为表添加外键完成性约束 报错Can't create table 'sfkbbs.#sql-513_25' (errno: 150)
aaarticlea/png;base64,iVBORw0KGgoAAAANSUhEUgAAAtkAAAAyCAIAAAAGM1ChAAAAA3NCSVQICAjb4U/gAAAgAElEQVR4Xu
- Linux列出安装过的程序
命令行: dpkg -l apt-cache(模糊搜索apt-cache search 包名) pkgnames yum list(ubuntu下试了无效) rpm -aq(ubuntu下试了无效)
- Lamp源码搭建
Lamp Centos6.5 + Apache/2.2.29 + PHP 5.3.29 + Mysql5.6.20 Apache(/usr/local/apache) PHP(/usr/local/b ...
- 基本概率分布Basic Concept of Probability Distributions 3: Geometric Distribution
PDF version PMF Suppose that independent trials, each having a probability $p$, $0 < p < 1$, o ...