介绍
传统上，在单应用程序中，我们对整个应用程序使用单个数据库服务器。但是，我将 SQL 数据库和 MongoDB 结合在同一个应用程序中。此应用程序将是 RDBMS 和 No SQL 数据库的组合。我们将从头开始创建一个 Blazor 应用程序，并使用数据迁移创建一个 SQL 数据库和一个表。我们将使用此 SQL DB 来保存员工数据。我们将使用 MongoDB 数据库来保存城市数据。我们可以一步一步地看到所有操作。
在 Visual Studio 中创建 Blazor 应用程序
我们可以使用 Blazor 服务器模板在 Visual Studio 中创建 Blazor 应用程序。
我们必须将以下库安装到我们的项目中。我们可以使用 NuGet 来安装这些库。
- “Microsoft.EntityFrameworkCore.SqlServer”
- “Microsoft.EntityFrameworkCore.Tools”
- “MongoDB.Driver”
我们可以在“Data”文件夹内创建一个具有以下属性的“Employee”类。
Employee.cs
namespace BlazorSQLAndMongoDB.Data
{public class Employee{public string Id { get; set; }public string Name { get; set; }public string Department { get; set; }public string Designation { get; set; }public string Company { get; set; }public string City { get; set; }}
}
我们可以在Data文件夹内创建一个“SqlDbContext”类，用于实体框架相关的操作。
SqlDbContext.cs
using Microsoft.EntityFrameworkCore;
namespace BlazorSQLAndMongoDB.Data
{public class SqlDbContext : DbContext{public SqlDbContext(DbContextOptions<SqlDbContext> options): base(options){}public DbSet<Employee> Employees { get; set; }}
}
我们可以在“appsettings.json”中为 SQL 数据库创建一个连接字符串。
我们使用了本地 SQL 服务器，该服务器可通过 Visual Studio 创建数据库和表。您可以根据需要使用任何 SQL 服务器。
我们必须在 Startup 类中的“ConfigureServices”方法中注册 SqlDbContext 类。
使用实体框架和数据迁移创建 SQL 数据库和表
我们可以使用工具菜单中的 NuGet 包管理器控制台，并使用以下迁移命令来创建 SQL 数据库和表。
add-migration Initial
上述命令将在“Migrations”文件夹内创建一个以当前时间戳为后缀的迁移脚本类。
我们可以使用以下命令来创建数据库和表。
update-database
数据库和表将很快创建。
我们可以创建一个“IEmployeeService”接口并在接口内声明以下方法。
IEmployeeService.cs
using System.Collections.Generic;
using System.Threading.Tasks;
namespace BlazorSQLAndMongoDB.Data
{public interface IEmployeeService{Task<List<Employee>> GetEmployees();Task<bool> CreateEmployee(Employee employee);Task<bool> EditEmployee(string id, Employee employee);Task<Employee> SingleEmployee(string id);Task<bool> DeleteEmployee(string id);}
}
我们可以从另一个类“EmployeeService”的接口中实现上述方法
EmployeeService.cs
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
namespace BlazorSQLAndMongoDB.Data
{public class EmployeeService : IEmployeeService{private readonly SqlDbContext _dbContext;public EmployeeService(SqlDbContext dbContext){_dbContext = dbContext;}public async Task<List<Employee>> GetEmployees(){return await _dbContext.Employees.ToListAsync();}public async Task<bool> CreateEmployee(Employee employee){employee.Id = Guid.NewGuid().ToString();_dbContext.Add(employee);try{await _dbContext.SaveChangesAsync();return true;}catch (DbUpdateException){return false;}}public async Task<Employee> SingleEmployee(string id){return await _dbContext.Employees.FindAsync(id);}public async Task<bool> EditEmployee(string id, Employee employee){if (id != employee.Id){return false;}_dbContext.Entry(employee).State = EntityState.Modified;await _dbContext.SaveChangesAsync();return true;}public async Task<bool> DeleteEmployee(string id){var employee = await _dbContext.Employees.FindAsync(id);if (employee == null){return false;}_dbContext.Employees.Remove(employee);await _dbContext.SaveChangesAsync();return true;}}
}
我们在服务类中添加了所有 CRUD 操作的逻辑。请注意，您甚至可以在没有接口的情况下创建此服务。
我们可以创建一个具有以下属性的 City 类。City 数据将存储在 MongoDB 中。
City.cs
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
namespace BlazorSQLAndMongoDB.Data
{public class City{[BsonId][BsonRepresentation(BsonType.ObjectId)]public string Id { get; set; }public string Name { get; set; }public string State { get; set; }}
}
我们可以将 MongoDB 连接字符串、数据库名称和集合名称保存在 appsettings.json 文件中，而不是对值进行硬编码。
我们必须创建一个接口和类来从 appsettings.json 文件中读取值。
我们可以创建“IMongoDbSettings”接口并声明以下属性。
IMongoDbSettings.cs
namespace BlazorSQLAndMongoDB.Data
{public interface IMongoDbSettings{string CollectionName { get; set; }string ConnectionString { get; set; }string DatabaseName { get; set; }}
}
我们可以创建“MongoDbSettings”类并在类内部继承IMongoDbSettings接口。
MongoDbSettings.cs
namespace BlazorSQLAndMongoDB.Data
{public class MongoDbSettings : IMongoDbSettings{public string CollectionName { get; set; }public string ConnectionString { get; set; }public string DatabaseName { get; set; }}
}
我们可以在Startup类中的ConfigureServices类里面注册这个接口和类。
我们可以创建一个“ICityService”接口并在接口内声明以下方法。
ICityService.cs
using System.Collections.Generic;
using System.Threading.Tasks;
namespace BlazorSQLAndMongoDB.Data
{public interface ICityService{Task<List<City>> GetCities();Task<bool> CreateCity(City city);Task<bool> EditCity(string id, City city);Task<City> SingleCity(string id);Task<bool> DeleteCity(string id);}
}
我们可以从另一个类“CityService”的接口中实现上述方法
ICityService.cs
using MongoDB.Driver;
using System.Collections.Generic;
using System.Threading.Tasks;
namespace BlazorSQLAndMongoDB.Data
{public class CityService : ICityService{private readonly IMongoCollection<City> _cities;public CityService(IMongoDbSettings settings){var client = new MongoClient(settings.ConnectionString);var database = client.GetDatabase(settings.DatabaseName);_cities = database.GetCollection<City>(settings.CollectionName);}public async Task<bool> CreateCity(City city){try{await _cities.InsertOneAsync(city);return true;}catch{return false;}}public async Task<bool> DeleteCity(string id){try{await _cities.DeleteOneAsync(city => city.Id == id);return true;}catch{return false;}}public async Task<bool> EditCity(string id, City city){try{await _cities.ReplaceOneAsync(book => book.Id == id, city);return true;}catch{return false;}}public async Task<List<City>> GetCities(){try{return await _cities.Find(city => true).ToListAsync();}catch{return null;}}public async Task<City> SingleCity(string id){try{return await _cities.Find<City>(city => city.Id == id).FirstOrDefaultAsync();}catch{return null;}}}
}
我们已经在上述类中注入了 IMongoDbSettings 接口，并从 appsettings.json 文件中获取了 MongoDB 配置值。
我们已经在上述服务类中添加了针对 City 实体的 CRUD 操作的所有逻辑。
我们可以在 Startup 类中注册 Employee 服务和 City 服务。
我们还可以在启动类中为 Blazor 服务器应用程序启用详细的电路错误。
配置服务（方法）
public void ConfigureServices(IServiceCollection services)
{services.AddRazorPages();services.AddServerSideBlazor();services.AddSingleton<WeatherForecastService>();services.AddDbContext<SqlDbContext>(options =>options.UseSqlServer(Configuration.GetConnectionString("SqlDbContext")));services.Configure<MongoDbSettings>(Configuration.GetSection(nameof(MongoDbSettings)));services.AddSingleton<IMongoDbSettings>(sp => sp.GetRequiredService<IOptions<MongoDbSettings>>().Value);services.AddScoped<IEmployeeService, EmployeeService>();services.AddScoped<ICityService, CityService>();services.AddServerSideBlazor().AddCircuitOptions(o => o.DetailedErrors = true);
}
我们已经完成了 Blazor 应用程序的后端部分。我们可以在“Pages”文件夹中创建所有用于 CRUD 操作的 Razor 组件。
我们可以先为City创建组件。
ListCities.razor
@using BlazorSQLAndMongoDB.Data
@page "/listcities"
@inject ICityService CityService
<h2>City Details</h2>
<p><a href="/addcity">Create New City</a>
</p>
@if (cities == null)
{<img src="./basicloader.gif" />
}
else
{<table class='table'><thead><tr><th>Name</th><th>State</th></tr></thead><tbody>@foreach (var city in cities){<tr><td>@city.Name</td><td>@city.State</td><td><a href='/editcity/@city.Id'>Edit</a><a href='/deletecity/@city.Id'>Delete</a></td></tr>}</tbody></table>
}
@code {List<City> cities;protected override async Task OnInitializedAsync(){cities = await CityService.GetCities();}
}
AddCity.razor
@using BlazorSQLAndMongoDB.Data
@page "/addcity"
@inject NavigationManager NavigationManager
@inject ICityService CityService
<h2>Create City</h2>
<hr />
<form><div class="row"><div class="col-md-8"><div class="form-group"><label for="Name" class="control-label">Name</label><input for="Name" class="form-control" @bind="@city.Name" /></div><div class="form-group"><label for="State" class="control-label">State</label><input for="State" class="form-control" @bind="@city.State" /></div></div></div><div class="row"><div class="col-md-4"><div class="form-group"><input type="button" class="btn btn-primary" @onclick="@CreateCity" value="Save"/><input type="button" class="btn" @onclick="@Cancel" value="Cancel" /></div></div></div>
</form>
@code {City city = new City();protected async Task CreateCity(){await CityService.CreateCity(city);NavigationManager.NavigateTo("listcities");}void Cancel(){NavigationManager.NavigateTo("listcities");}
}
EditCity.razor
@using BlazorSQLAndMongoDB.Data
@page "/editcity/{id}"
@inject NavigationManager NavigationManager
@inject ICityService CityService
<h2>Edit City</h2>
<hr />
<form><div class="row"><div class="col-md-8"><div class="form-group"><label for="Name" class="control-label">Name</label><input for="Name" class="form-control" @bind="@city.Name" /></div><div class="form-group"><label for="State" class="control-label">State</label><input for="State" class="form-control" @bind="@city.State" /></div></div></div><div class="row"><div class="form-group"><input type="button" class="btn btn-primary" @onclick="@UpdateCity" value="Update" /><input type="button" class="btn" @onclick="@Cancel" value="Cancel" /></div></div>
</form>
@code {[Parameter]public string id { get; set; }City city = new City();protected override async Task OnInitializedAsync(){city = await CityService.SingleCity(id);}protected async Task UpdateCity(){await CityService.EditCity(id, city);NavigationManager.NavigateTo("listcities");}void Cancel(){NavigationManager.NavigateTo("listcities");}
}
DeleteCity.razor
@using BlazorSQLAndMongoDB.Data
@page "/deletecity/{id}"
@inject NavigationManager NavigationManager
@inject ICityService CityService
<h2>Confirm Delete</h2>
<p>Are you sure you want to delete this City with Id: <b>@id</b></p>
<br />
<div class="col-md-4"><table class="table"><tr><td>Name</td><td>@city.Name</td></tr><tr><td>State</td><td>@city.State</td></tr></table><div class="form-group"><input type="button" value="Delete" @onclick="@Delete" class="btn btn-primary" /><input type="button" value="Cancel" @onclick="@Cancel" class="btn" /></div>
</div>
@code {[Parameter]public string id { get; set; }City city = new City();protected override async Task OnInitializedAsync(){city = await CityService.SingleCity(id);}protected async Task Delete(){await CityService.DeleteCity(id);NavigationManager.NavigateTo("listcities");}void Cancel(){NavigationManager.NavigateTo("listcities");}
}
我们现在可以为员工创建组件。
ListEmployees.razor
@using BlazorSQLAndMongoDB.Data
@page "/listemployees"
@inject IEmployeeService EmployeeService
<h2>Employee Details</h2>
<p><a href="/addemployee">Create New Employee</a>
</p>
@if (employees == null)
{<img src="./basicloader.gif" />
}
else
{<table class='table'><thead><tr><th>Name</th><th>Department</th><th>Designation</th><th>Company</th><th>City</th></tr></thead><tbody>@foreach (var employee in employees){<tr><td>@employee.Name</td><td>@employee.Department</td><td>@employee.Designation</td><td>@employee.Company</td><td>@employee.City</td><td><a href='/editemployee/@employee.Id'>Edit</a><a href='/deleteemployee/@employee.Id'>Delete</a></td></tr>}</tbody></table>
}
@code {List<Employee> employees;protected override async Task OnInitializedAsync(){employees = await EmployeeService.GetEmployees();}
}
AddEmployee.razor
@using BlazorSQLAndMongoDB.Data
@page "/addemployee"
@inject NavigationManager NavigationManager
@inject IEmployeeService EmployeeService
@inject ICityService CityService
<h2>Create Employee</h2>
<hr />
<form><div class="row"><div class="col-md-8"><div class="form-group"><label for="Name" class="control-label">Name</label><input for="Name" class="form-control" @bind="@employee.Name" /></div><div class="form-group"><label for="Department" class="control-label">Department</label><input for="Department" class="form-control" @bind="@employee.Department" /></div><div class="form-group"><label for="Designation" class="control-label">Designation</label><input for="Designation" class="form-control" @bind="@employee.Designation" /></div><div class="form-group"><label for="Company" class="control-label">Company</label><input for="Company" class="form-control" @bind="@employee.Company" /></div><div class="form-group"><label asp-for="City" class="control-label">City</label><select asp-for="City" class="form-control" @bind="@employee.City"><option value="">-- Select City --</option>@foreach (var city in cities){<option value="@city.Name">@city.Name</option>}</select></div></div></div><div class="row"><div class="col-md-4"><div class="form-group"><input type="button" class="btn btn-primary" @onclick="@CreateEmployee" value="Save" /><input type="button" class="btn" @onclick="@Cancel" value="Cancel" /></div></div></div>
</form>
@code {Employee employee = new Employee();List<City> cities = new List<City>();protected override async Task OnInitializedAsync(){cities = await CityService.GetCities();}protected async Task CreateEmployee(){await EmployeeService.CreateEmployee(employee);NavigationManager.NavigateTo("listemployees");}void Cancel(){NavigationManager.NavigateTo("listemployees");}
}
请注意，我已在上述组件中注入了城市服务和员工服务。城市组件用于从 MongoDB 获取城市名称，员工服务用于将所有员工数据保存在 SQL 数据库中。
EditEmployee.razor
@using BlazorSQLAndMongoDB.Data@page "/editemployee/{id}"
@inject NavigationManager NavigationManager
@inject IEmployeeService EmployeeService
@inject ICityService CityService
<h2>Edit Employee</h2>
<hr />
<form><div class="row"><div class="col-md-8"><div class="form-group"><label for="Name" class="control-label">Name</label><input for="Name" class="form-control" @bind="@employee.Name" /></div><div class="form-group"><label for="Department" class="control-label">Department</label><input for="Department" class="form-control" @bind="@employee.Department" /></div><div class="form-group"><label for="Designation" class="control-label">Designation</label><input for="Designation" class="form-control" @bind="@employee.Designation" /></div><div class="form-group"><label for="Company" class="control-label">Company</label><input for="Company" class="form-control" @bind="@employee.Company" /></div><div class="form-group"><label asp-for="City" class="control-label">City</label><select asp-for="City" class="form-control" @bind="@employee.City"><option value="">-- Select City --</option>@foreach (var city in cities){<option value="@city.Name">@city.Name</option>}</select></div></div></div><div class="row"><div class="form-group"><input type="button" class="btn btn-primary" @onclick="@UpdateEmployee" value="Update" /><input type="button" class="btn" @onclick="@Cancel" value="Cancel" /></div></div>
</form>@code {[Parameter]public string id { get; set; }Employee employee = new Employee();List<City> cities = new List<City>();protected override async Task OnInitializedAsync(){cities = await CityService.GetCities();employee = await EmployeeService.SingleEmployee(id);}protected async Task UpdateEmployee(){await EmployeeService.EditEmployee(id, employee);NavigationManager.NavigateTo("listemployees");}void Cancel(){NavigationManager.NavigateTo("listemployees");}
}
该组件也被注入到City服务和Employee服务中。
DeleteEmployee.razor
@using BlazorSQLAndMongoDB.Data
@page "/deleteemployee/{id}"
@inject NavigationManager NavigationManager
@inject IEmployeeService EmployeeService
<h2>Confirm Delete</h2>
<p>Are you sure you want to delete this Employee with Id: <b>@id</b></p>
<br />
<div class="col-md-4"><table class="table"><tr><td>Name</td><td>@employee.Name</td></tr><tr><td>Department</td><td>@employee.Department</td></tr><tr><td>Designation</td><td>@employee.Designation</td></tr><tr><td>Company</td><td>@employee.Company</td></tr><tr><td>City</td><td>@employee.City</td></tr></table><div class="form-group"><input type="button" value="Delete" @onclick="@Delete" class="btn btn-primary" /><input type="button" value="Cancel" @onclick="@Cancel" class="btn" /></div>
</div>
@code {[Parameter]public string id { get; set; }Employee employee = new Employee();protected override async Task OnInitializedAsync(){employee = await EmployeeService.SingleEmployee(id);}protected async Task Delete(){await EmployeeService.DeleteEmployee(id);NavigationManager.NavigateTo("listemployees");}void Cancel(){NavigationManager.NavigateTo("listemployees");}
}
NavMenu.razor
<div class="top-row pl-4 navbar navbar-dark"><a class="navbar-brand" href="">Blazor with SQL and Mongo</a><button class="navbar-toggler" @onclick="ToggleNavMenu"><span class="navbar-toggler-icon"></span></button>
</div>
<div class="@NavMenuCssClass" @onclick="ToggleNavMenu"><ul class="nav flex-column"><li class="nav-item px-3"><NavLink class="nav-link" href="" Match="NavLinkMatch.All"><span class="oi oi-home" aria-hidden="true"></span> Home</NavLink></li><li class="nav-item px-3"><NavLink class="nav-link" href="listcities"><span class="oi oi-plus" aria-hidden="true"></span> City details</NavLink></li><li class="nav-item px-3"><NavLink class="nav-link" href="listemployees"><span class="oi oi-list-rich" aria-hidden="true"></span> Employee details</NavLink></li></ul>
</div>
@code {bool collapseNavMenu = true;string NavMenuCssClass => collapseNavMenu ? "collapse" : null;void ToggleNavMenu(){collapseNavMenu = !collapseNavMenu;}
}
我们已经删除了默认创建的计数器和天气数据的路由。
我们已经完成了整个编码部分。我们可以运行该应用程序了。请确保您的 MongoDB Windows 服务正在运行。
我们可以创建一个新的城市数据。
保存数据后，您可以使用 MongoDB 指南针软件检查 MongoDB 数据。
我们可以在那里看到新添加的城市数据。
我们现在可以创建新的员工数据。
我们可以再添加一个员工详细信息，并在网格中列出两个员工详细信息。
我们已成功通过申请添加了两个城市和两名员工。
结论
在这篇文章中，我们了解了如何在同一个 Blazor 应用程序中结合 SQL DB 和 MongoDB。我们已成功在单个应用程序中集成了 RDBMS 和 No SQL 功能。
