node database migrations

. Build the Database Modify 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 statem

model changes, the current database is deleted and the new database is rebuilt.After the code executes, the resulting database:　　2. EF 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

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.setinitializer1>, in the Package Manager console, execute the statement:Pm> enable-migrations-enableautomatic

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 migratio

1, VS, Package Manager console2, implementation,enable-migrationsError:Migrations has already been enabled in project ' DD '. To overwrite the existing migrations configuration with use The-force parameter.3, implementation,enable-migrations -forceError:The Migrations configuration type ' DD. Configuration ' is not being found in the assembly ' DD '.Reason:When e

) { //Builder. Usesqlserver (connection); Builder. Usemysql (connection); } } 5. Modify the database link string In the Web project configuration file Appsettings.json "ConnectionStrings": { //"Default": "Server=localhost; DATABASE=ABPBASICDB; trusted_connection=true; " " Default ":" Server=localhost; port=3306; DATABASE=ABPBASICDB;

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

EF Code First Migrations database migration, efmigrations1. EF Code First creates a database Step 1: Create a console application Step 2: Install EntityFramework Run the following statement on the Package Manager Console: PM> Install-Package EntityFramework2. Project Structure Two entities and ing. The PortalContext code is as follows: using System;using Sy

# import terminal commands app = Flask (__name__) # Initialize Flaskmanager = Manager (APP) # Create terminal Command object app.config[ ' mysql://root:[emailprotected]:3306/flask_test ' # Link database app.config[ SQLALCHEMY_ Track_modifications '] = true # Turn on event Tracking db = SQLAlchemy (APP) # Initialize database object # use the migration class to save the application and

to add data to the table. Add data to the table, INSERT statements like database tablesB = BookInfo() b.btitle = ‘abc b.save() Modify table data, similar to a table update operationB = BookInfo.objects.get(pk=1) pk是主键 primarykehy b.btitle =‘abc‘ b.save() Query tableBookInfo.objects.all() Delete a tableb.delete() BookInfo.objects.all() 查看结果 The test flow is as follows:A virtual environment t

(10)] public string teacherName { get; set; } public virtual UserInfo UserInfo{get;set;}} Note: The difference is that we have added a length limit to the teachername attribute. Next, we will start to persist this model to the database (now we only modify the attribute. In this case, the length of this field in the database is nvarchar (max), not nvarchar (10 )) 1: configure the