internal static async Task DbContextTransactionAsync(AdventureWorks adventureWorks)
{
await adventureWorks.Database.CreateExecutionStrategy().ExecuteAsync(async() =>
{
using (IDbContextTransaction transaction = await adventureWorks.Database.BeginTransactionAsync(
IsolationLevel.ReadUncommitted))
{
try
{
adventureWorks.CurrentIsolationLevel().WriteLine(); // ReadUncommitted
ProductCategory category = new ProductCategory()
{
Name = nameof(ProductCategory)
};
await adventureWorks.ProductCategories.AddAsync(category);
(await adventureWorks.SaveChangesAsync()).WriteLine(); // 1
await adventureWorks.Database.ExecuteSqlCommandAsync(
sql: "DELETE FROM [Production].[ProductCategory] WHERE [Name] = {0}",
parameters: nameof(ProductCategory)).WriteLine(); // 1
transaction.Commit();
}
catch
{
transaction.Rollback();
throw;
}
}
});
}
internal static async Task DbTransactionAsync()
{
using (SqlConnection connection = new SqlConnection(ConnectionStrings.AdventureWorks))
{
await connection.OpenAsync();
using (DbTransaction transaction = connection.BeginTransaction(IsolationLevel.Serializable))
{
try
{
using (AdventureWorks adventureWorks = new AdventureWorks(connection))
{
await adventureWorks.Database.CreateExecutionStrategy().ExecuteAsync(async() =>
{
adventureWorks.Database.UseTransaction(transaction);
adventureWorks.CurrentIsolationLevel().WriteLine(); // Serializable
ProductCategory category = new ProductCategory()
{
Name = nameof(ProductCategory)
};
await adventureWorks.ProductCategories.AddAsync(category);
(await adventureWorks.SaveChangesAsync()).WriteLine(); // 1.
});
}
using (DbCommand command = connection.CreateCommand())
{
command.CommandText = "DELETE FROM [Production].[ProductCategory] WHERE [Name] = @p0";
DbParameter parameter = command.CreateParameter();
parameter.ParameterName = "@p0";
parameter.Value = nameof(ProductCategory);
command.Parameters.Add(parameter);
command.Transaction = transaction;
(await command.ExecuteNonQueryAsync()).WriteLine(); // 1
}
transaction.Commit();
}
catch
{
transaction.Rollback();
throw;
}
}
}
}
internal static async Task Async(AdventureWorks adventureWorks)
{
IQueryable <ProductCategory> categories = adventureWorks.ProductCategories;
await categories.ForEachAsync( // Async version of foreach/ForEach.
category => category.Name.WriteLine());
ProductSubcategory subcategory = await adventureWorks.ProductSubcategories
.FirstAsync(entity => entity.Name.Contains("Bike")); // Async version of First.
subcategory.Name.WriteLine();
Product[] products = await adventureWorks.Products
.Where(product => product.ListPrice <= 10)
.ToArrayAsync(); // Async version of ToArray.
adventureWorks.Products.RemoveRange(products);
(await adventureWorks.SaveChangesAsync()).WriteLine(); // Async version of SaveChanges.
}
internal static async Task SaveChangesAsync()
{
using (AdventureWorks adventureWorks1 = new AdventureWorks())
using (AdventureWorks adventureWorks2 = new AdventureWorks())
{
int id = 950;
Product productCopy1 = await adventureWorks1.Products.FindAsync(id);
Product productCopy2 = await adventureWorks2.Products.FindAsync(id);
productCopy1.Name = nameof(productCopy1);
productCopy1.ListPrice = 100;
(await adventureWorks1.SaveChangesAsync()).WriteLine(); // 1
productCopy2.Name = nameof(productCopy2);
productCopy2.ProductSubcategoryID = 1;
(await adventureWorks2.SaveChangesAsync(RefreshConflict.MergeClientAndStore)).WriteLine(); // 1
}
}
