code first migrations

Code First Database migration2.1. Build the DatabaseModify the static constructor of the class file PortalContext.cs to remove the setting that removes the current database from rebuilding the new database when the database model has changed.Static Portalcontext () { database.setinitializer 1>, in the Package Manager console, execute the statement:Pm> enable-migrations-enableautomaticmigrations After s

Label:1. Open Tool->nuget Program Manager, Package Manager consoleThe project where the data access context class is to be selected in the default projectMy db is under the namespace Codefirst.ui, so choose Codefirst.uiThen execute enable-migrationsIf it fails, there is an error that warns you that you are not installing XXXX or missing xxxx (once, the error message is not retained, the next time you have a chance to add),Need to install(I don't know what the hell it is);To the official Web down

.Models.UsersContext.To Enable Migrations for MvcApplication1.Models.MovieDBContext, use Enable-migrations-contexttypename MvcApplication1.Models.MovieDBContext.To Enable Migrations for mvcapplication1.purchaserequestentities, use Enable-migrations-contexttypename mvcapplication1.purchaserequestentities. This is be

automatic migration instead, delete the Migrations folder and re-run enable-migrations specifying The-enableaut Omaticmigrations parameter.Code first migrations enabled for Project MvcApplication1.The following folder appears in the project:Opening the Configuation.cs will make the following changes:[CSharp]View PlainCopy Public Configuration () {

enabled for Project MvcApplication1.The following folder appears in the project:Opening the Configuation.cs will make the following changes:1 Public Configuration () 2 {3 true; 4 }Execute Update-database again:Since I changed the length from Max to 10, when I update the data structure, it thinks this operation will result in data loss, as follows:Specify the '-verbose ' flag to view the SQL statements being applied to the target database.No pending

Command keyword summary: Install-package entityframework Enable-migrations Add-migration Update-Database Update-database-verbose (related scripts are displayed in the Package Manager Console and finally applied to the database) Update-database-script-sourcemigration: $ initialdatabase-targetmigration: "addblogurl" (where addblogurl is migration name, which is the generated SQL file but instead of actually applying the changes) Update-

;} [Required] [MaxLength (50)] public string Lessonname { get;set;} [Required] [MaxLength (10)] public string TeacherName { get;set;} public Virtual UserInfo userinfo{get; Set;} } Note: The difference is that we add a length limit to the TeacherName attribute.Next, we're going to start persisting this model into the database (we're just modifying the property now, the length of this field in the database is nvarchar (max), not nvarchar (10))1: Configure the database connecti

Document directory -EnableAutomaticMigrations -ProjectName -Force -Name -Force -ProjectName -StartUpProjectName -ConfigurationTypeName -ConnectionStringName -ConnectionString -ConnectionProviderName -IgnoreChanges -SourceMigration -TargetMigration -Script -Force -ProjectName -StartUpProjectName -ConfigurationTypeName -ConnectionStringName -ConnectionString -ConnectionProviderName -ProjectName -StartUpProjectName -ConfigurationTypeName -Connect

Tags: images version Rbo ACK Mic application generated back enabledWhen developing a database application, it is often encountered that some tables need to add fields or modify types, new tables, and so on, whereas for EF Code first there are only entity classes that need to be added to a new entity class or added, removed, or deleted in the entity class when requirements change. You can modify the properties. But how do I synchronize the changes to t

1. Concept　　Entity Framework: The ADO Entity Framework is an object-relational (O/R Mapping) solution developed by Microsoft on the basis of ADO. (This is only a database application that understands. NET Features Program (O/R mapping), such as Hibernate, is not in-depth here, pending additional learning later. In short, Microsoft has helped you connect the database is an Entity Framework, so that you can operate more convenient, not too much to write SqlHelper and LINQ statement LAMDA expressio

settings into your default TEMPLATES dict: TEMPLATE_DEBUG.BEGIN; create table 'getssh _ publisher '('id' integer AUTO_INCREMENT not null primary key, 'name' varchar (30) not null, 'address' varchar (50) not null, 'city' varchar (60) NOT NUL L, 'state _ province 'varchar (30) not null, 'country' varchar (50) not null, 'website' varchar (200) not null ); create table 'getssh _ author' ('id' integer AUTO_INCREMENT not null primary key, 'First _ name' varchar (30) not null, 'last _ name' varchar (4

Open the MVC Project today (Code-first) and plan to update the database manually, so do this directly in the Package management console:Enable-migrations-contexttypename bjylonlineserv.areas.enterprise.dal.enterprisecontext-migrationsdirectory Migrations\enterprise;Console directly gave me a mistake like this, I am surprised, before the good ah, what happened. Er

version Next: Migrating to the next version Latest: Migrating to the latest version (same as no version number effect) Common commands# 生成迁移脚本 php migration.php migrations:generate # 执行迁移到最新版本 php migration.php migrations:migrate # --dry-run是空转参数，只显示操作结果，不执行修改 php migration.php migrations:migrate --dry-run # 不执行操作，只写入文件，对于生产环境需要手动验证并执行的场景有用 php migration.php migrations:migrate --write-sql=file.sql # 查看详细信息 php migration.php statusConclusionTo this, we have learned the basic use of

This article introduces databasemigrations, one of the most powerful functions in the Laravel5 framework. This article describes in detail the steps and methods of database migration, which is very practical, if you have any need, refer. Database migrations is one of laravel's most powerful functions. Database migration can be understood as the version controller of the database. The database/migrations di

Laravel 5 framework learning-database migration (Migrations), laravelmigrations Database migrations is one of laravel's most powerful functions. Database migration can be understood as the version controller of the database. The database/migrations directory contains two migration files, one for creating a user table and the other for resetting the user password.

Error message: the 'title' Column cannot be inserted with a null value. Table 'mvccorperation. Models. corperationdbcontext. DBO. Articles '; the column cannot have a null value. Update failed. The statement has been terminated. Environment: A

migration warehouseFirst, we want to install flask-migrate in a virtual environment:Pip Install Flask-migrateThe initialization method for this extension is as follows:from = Migrate (app, db) Manager.add_command ('db', Migratecommand)To export the database Migration command, Flask-migrate provides a Migratecommand class that can be attached to the Flask-script Manager object. In this example, the Migratecommand class is appended with the DB command.To create a migration warehouse using the INI

Tags: port self NEC ROP Statement enhanced real-time project WanScenarios and BenefitsOnce you are familiar with the Symfony framework, you have a deep sense of the power of the framework-integrated ORM component Doctrine2, and the accompanying data migration is also very convenient. Doctrine2 uses the doctrine Dbal component to migrate data in a way that compares the table structure in the code to the table structure in the actual database. This is m

Tags: cdb. JSON get UI Management OID console configuration confI. Migration instructions The ABP Template project entity Framework Core uses SQL Server by default, and it is easy to migrate the database to MySQL, as follows. Ii. migrating MySQL Steps 1. Download the project Go to Http://aspnetboilerplate.com/Templates to download a new project, select the ASP. NET Core 2.x tag, Target Framework: check. 2. Remove the default SQL Server related packages Remove the package Microsoft.EntityFramewor

Example: public int Create() { // Create the ActionLinkPartRecord table SchemaBuilder.CreateTable("ActionLinkPartRecord", table => table .ContentPartRecord() .Column("ActionName", c =>