//creating seed method to create the tables from catalog context
public static void OnSeed(CatalogContext context)
{
//we are migrating the c# code in to the tables in the db
context.Database.Migrate();
//adding the data into the tables only if the data is not available
if (!context.CatalogBrands.Any())
{
//add range is like adding data into the tables
context.CatalogBrands.AddRange(GetPreConfiguredCatalogBrand());
//saving the changes in our table after adding the content
context.SaveChanges();
}
//if there is no data in the catalog types then adding the data into the table
if (!context.CatalogTypes.Any())
{
context.CatalogTypes.AddRange(GetPreConfiguredCatalogType());
context.SaveChanges();
}
//if there is no data in the catalog items then adding the data into the table
if (!context.CatalogItems.Any())
{
context.CatalogItems.AddRange(GetPreConfiguredCatalogItems());
context.SaveChanges();
}
}
// contact with data(CatalogContext)
public static void Seed(CatalogContext context)
{
// before writing the data check migration is available
// or my table or schema is ready
context.Database.Migrate();
// don't want to add data multiple times so check if there is no data in the table
// context is your DB, CatalogBrands is the table
if (!context.CatalogBrands.Any())
{
// add multiple rows of data by using AddRange()
context.CatalogBrands.AddRange(GetPreConfiguredCatalogBrands());
// commit data
context.SaveChanges();
}
if (!context.CatalogTypes.Any())
{
context.CatalogTypes.AddRange(GetPreConfiguredCatalogTypes());
context.SaveChanges();
}
if (!context.CatalogItems.Any())
{
context.CatalogItems.AddRange(GetPreConfiguredCatalogItems());
context.SaveChanges();
}
}
// Powershell is the C# scripting language
// Need to run two Powershell commands to make Entity Framework work
// Already:
// Wrote classes (CatalogBrand, CatalogItem, CatalogType)
// And DbContext (CatalogContext)
// Powershell script is what causes the conversion path to the db
// 1. AddMigration
// Takes your rules that you specified in your DbContext
// Converts it into SQL
// Will do deltas
// First time is everything
// 2. UpdateDatabase
// Takes the migration (from step 1) and actually push to db (create tables, etc.)
// Need to do these two commands again each time your Domain classes
// or DbContext change
// Automation of these sounds convenient
// Conceptually AddMigration as manual step is important because
// what if you are developing something and it is not ready yet
// for the database
// UpdateDatabase, though, that could be automated
// After you have run AddMigration, it is safe to do
// Put this at the start of the Seed method:
// Pass in the context to the catalog, that is a reference to the db
// so this knows where to populate the data
public static void Seed(CatalogContext context)
// A CatalogContext is a connection to a db
{
// This is the same as UpdateDatabase Powershell command
// If there are migrations wating to be sent to the database, send them
context.Database.Migrate();
// Check for pending migrations and push them
// If no pending migrations exist, do nothing
// In production, the Migrate() call (UpdateDatabase)
// is the only thing here in Seed() that you'll do
// Everything else is just for class purposes.
// Populate the tables with data
if (!context.CatalogBrands.Any())
// Any is a LINQ query...are there any records?
// If there are no rows in the table
{
// Only then do we seed the table with data
// Recall the three tables DbSet<> in CatalogContext : DbContext
// CatalogBrands, CatalogTypes and CatalogItems
// This is how you can talk to your table from code:
context.CatalogBrands.AddRange(GetPreconfiguredCatalogBrands());
// Just one line in Entity Framework (not 10 lines of SQL query)
// .Add() for one row, .AddRange() for multiple rows
// Must save, otherwise changes not committed
context.SaveChanges();
// SaveChanges() seperate command so that you can group/bulk add
// Then save as a final step
// But in this case, saving before adding CatalogItems is important,
// because CatalogItems has dependencies on CatalogBrands and
// CatalogTypes
}
if (!context.CatalogTypes.Any())
{
context.CatalogTypes.AddRange(GetPreconfiguredCatalogTypes());
context.SaveChanges();
}
if (!context.CatalogItems.Any())
{
context.CatalogItems.AddRange(GetPreconfiguredCatalogItems());
context.SaveChanges();
}
}
public static void Seed(CatalogContext context)
{
context.Database.Migrate();
if (!context.CatalogBrands.Any())
{
context.CatalogBrands.AddRange(GetPreConfiguredCatalogBrands());
context.SaveChanges();
}
if (!context.CatalogTypes.Any())
{
context.CatalogTypes.AddRange(GetPreConfiguredCatalogTypes());
context.SaveChanges();
}
if (!context.CatalogItems.Any())
{
context.CatalogItems.AddRange(GetPreConfiguredCatalogItems());
context.SaveChanges();
}
}
//Populate my db table with some sample data - Module 11 - talking about static - 1 global instance for everyone to use
// here catalog context refers to the connection to the database - where we need to populate the data
// all methods should be static -seed it with data (using powershell)
// Entity framework to work we need to run 2 power shell commands
// pathway 1 . add migration is to take context defn and make a sql syntax to translate c# to sql command
// 1st time all the data has to be migrated, 2nd time would be update migration to the database
public static void Seed(CatalogContext context)
{
// Here only update migration is automated
context.Database.Migrate();
if (!context.CatalogBrands.Any())
{
context.CatalogBrands.AddRange(GetPreConfiguredCatalogBrands());
context.SaveChanges(); // Very important to commit the changes
}
if (!context.CatalogTypes.Any())
{
context.CatalogTypes.AddRange(GetPreConfiguredCatalogTypes());
context.SaveChanges();
}
if (!context.CatalogItems.Any())
{
context.CatalogItems.AddRange(GetPreConfiguredCatalogItems());
context.SaveChanges();
}
}
public static void Seed(CatalogContext context)
{
context.Database.Migrate();
if (!context.CatalogEventCategories.Any())
{
context.CatalogEventCategories.AddRange(GetPreConfiguredCatalogEventCategories());
context.SaveChanges();
}
if (!context.CatalogEventTypes.Any())
{
context.CatalogEventTypes.AddRange(GetPreConfiguredCatalogEventTypes());
context.SaveChanges();
}
if (!context.CatalogEventLocations.Any())
{
context.CatalogEventLocations.AddRange(GetPreConfiguredCatalogEventLocations());
context.SaveChanges();
}
if (!context.CatalogEventItems.Any())
{
context.CatalogEventItems.AddRange(GetPreConfiguredCatalogEventItems());
context.SaveChanges();
}
}