Part 5 - How to handle model changes in entity framework
Part 6 - How to seed database with test data using entity framework
Part 7 - Using stored procedures with entity framework
এই আর্টিকেলে আমরা entity framework এর code first approach এ stored procedures এর মাধ্যমে কিভাবে Insert, Update এবং Delete operations গুলো perform করতে হয় তা নিয়ে আলোচনা করবো।
এই আর্টিকেলের explanations ভালভাবে বুঝতে নিচের video টি একবার দেখে আসুন। ধন্যবাদ।।
N.B: Practical ধাপগুলো আমি আপনাদের বোঝার সুবিধার জন্য English এ explain করবো। এই step গুলো VS2017(Visual Studio 2017) এ execute করা হয়েছে।
Step 1: Create a new empty asp.net web application project. Name it Demo. Install entity framework if it's not already installed.
Step 2: Add a class file to the project. Name it Employee.cs. Copy and paste the following code.
namespace Demo
{
public class Employee
{
public int ID { get; set; }
public string Name { get; set; }
public string Gender { get; set; }
public int Salary { get; set; }
}
}
Step 3: Add a class file to the project. Name it EmployeeDBContext.cs. Copy and paste the following code.
using System.Data.Entity;
namespace Demo
{
public class EmployeeDBContext : DbContext
{
public DbSet<Employee> Employees { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// This line will tell entity framework to use stored procedures
// when inserting, updating and deleting Employees
modelBuilder.Entity<Employee>().MapToStoredProcedures();
base.OnModelCreating(modelBuilder);
}
}
}
Step 4: Add a class file to the project. Name it EmployeeRepository.cs. Copy and paste the following code.
using System.Collections.Generic;
using System.Linq;
namespace Demo
{
public class EmployeeRepository
{
EmployeeDBContext employeeDBContext = new EmployeeDBContext();
public List<Employee> GetEmployees()
{
return employeeDBContext.Employees.ToList();
}
public void InsertEmployee(Employee employee)
{
employeeDBContext.Employees.Add(employee);
employeeDBContext.SaveChanges();
}
public void UpdateEmployee(Employee employee)
{
Employee employeeToUpdate = employeeDBContext
.Employees.SingleOrDefault(x => x.ID == employee.ID);
employeeToUpdate.Name = employee.Name;
employeeToUpdate.Gender = employee.Gender;
employeeToUpdate.Salary = employee.Salary;
employeeDBContext.SaveChanges();
}
public void DeleteEmployee(Employee employee)
{
Employee employeeToDelete = employeeDBContext
.Employees.SingleOrDefault(x => x.ID == employee.ID);
employeeDBContext.Employees.Remove(employeeToDelete);
employeeDBContext.SaveChanges();
}
}
}
Step 5: Add the database connection string in web.config file.
<connectionStrings>
<add name="EmployeeDBContext"
connectionString="server=.; database=Sample; integrated security=true;"
providerName="System.Data.SqlClient" />
</connectionStrings>
Step 6: Add a webform to the project. Drag and drop the following 3 controls and build the solution.
1. GridView
2. DetailsView
3. ObjectDataSource
Step 7: Configure ObjectDataSource control
a) Right click on the ObjectDataSource control and select "Show Smart Tag" option
b) Click on Configure Data Source link
c) Select Demo.EmployeeRepository on Choose a Business Object screen and click Next
d) On Define Data Methods screen
i) On SELECT tab - Select GetEmployees() method
ii) On UPDATE tab - Select UpdateEmployees(Employee employee) method
iii) On INSERT tab - Select InsertEmployees(Employee employee) method
iv) On DELETE tab - Select DeletEmployees(Employee employee) method
Step 8: Configure GridView control
a) Right click on GridView control and select "Show Smart Tag" option
b) Click on "Auto Format" link and select "Colourful" scheme
c) Select "ObjectDataSource1" from "Choose Data Source" dropdownlist
d) Select Enable Editing and Enable Deleting checkboxes
e) Set DataKeyNames="ID". Do this in the properties window of the GridView control
Step 9: Configure DetailsView control
a) Right click on DetailsView control and select "Show Smart Tag" option
b) Click on "Auto Format" link and select "Colourful" scheme
c) Select "ObjectDataSource1" from "Choose Data Source" dropdownlist
d) Select Enable Inserting checkbox
e) Set DeafultMode=Insert. Use properties window to set this.
f) Set InsertVisible="false" for the ID BoundField. You can do this directly in the HTML Source.
Step 10: If you already have Sample database in SQL Server. Delete it from SQL Server Management Studio.
Step 11: Run the application by pressing CTRL + F5. Notice that we don't have any data displayed on WebForm1. This is because we don't have any data in the Employees table.
At this point, we have the Sample database and Employees table created automatically. The following stored procedures are also automatically generated.
Employee_Delete
Employee_Insert
Employee_Update
By default, the following should be the naming convention for the stored procedures.
INSERT stored procedure - [Entity_Name]_Insert. Insert Stored procedure should return the auto-generated identity column value.
UPDATE stored procedure - [Entity_Name]_Update
DELETE stored procedure - [Entity_Name]_Delete
Step 12: Use the below SQL script to populate Employees tables with test data.
Insert into Employees values ('Mark', 'Male', 60000)
Insert into Employees values ('Steve', 'Male', 45000)
Insert into Employees values ('Ben', 'Male', 70000)
Insert into Employees values ('Philip', 'Male', 45000)
Insert into Employees values ('Mary', 'Female', 30000)
Insert into Employees values ('Valarie', 'Female', 35000)
Insert into Employees values ('John', 'Male', 80000)At this point,
1. Run SQL Prrofiler
2. Run the application
3. Insert, Update and Delete Employees, and notice that the respective stored procedures are being called as expected.
Output should be look like following-
 |
| Output WebForm |
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