如何在 ASP.NET 核心与 PostgreSQL 建立数据库连接？

Question

How to make database connection in ASP.NET core with postgres SQL?

Answer 1

use the Npgsql EF Core provider, add a dependency on Npgsql.EntityFrameworkCore.PostgreSQL. You can follow the instructions in the general EF Core Getting Started docs. https://www.npgsql.org/efcore/

Answer 2

Question: How to make database connection in ASP.NET core with postgres SQL?

There are two ways you add your postgresql database along with the asp.net core project.

Using follwing way:

• ADO.net connection provider
• Nuget extension: Npgsql.EntityFrameworkCore.PostgreSQL

ADO.net connection provider

Here would just need the NpgsqlConnection connection builder class which will execute your sql on Postgre sql database server. See the example below:

C# ASP.NET Core & Postgre SQL Ado.net example:

  NpgsqlConnection conn = new NpgsqlConnection("Server=127.0.0.1;User Id=postgres;Password=pwd;Database=postgres;");
    
    conn.Open();
    
    // Passing PostGre SQL Function Name
    NpgsqlCommand command = new NpgsqlCommand("EXE GetEmployeePrintInfo", conn);
    
    // Execute the query and obtain a result set
    NpgsqlDataReader reader = command.ExecuteReader();
    
    // Reading from the database rows
    List<string> listOfManager = new List<string>();

    while (reader.Read())
    {
        string WSManager = reader["WSManager"].ToString(); // Remember Type Casting is required here it has to be according to database column data type
        listOfManager.Add(WSManager);
    }
    reader.Close();

    command.Dispose();
    conn.Close();

Npgsql.EntityFrameworkCore.PostgreSQL:

You have to add Nuget extension into the project reference from manage Nuget Packages using Visual studio . Entity framework core has this functionality for many database providers. Just follow below steps on visual studio

ConfigureServices in startup.cs: Once you successfully added the Nuget package then you have to update following code on your project ConfigureServices under startup.cs

        services.AddDbContext<YourDatabaseContextClassName>(options =>
        options.UseNpgsql(Configuration.GetConnectionString("YourDatabaseContextStringNameFromAppsettings")));

Note: If you need any example for entityframework and Postgre SQL implementation you can have look here

For further assistance you can have look on official document here . Hope it would guide you accordingly.