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[英]Value cannot be null. Parameter name: connectionString when i run add-migration
[英]Value cannot be null. Parameter name: connectionString
因此,我一直在研究stackoverflow並檢查與我的問題有關的所有問題,所有內容都已簽出,但是我仍然遇到相同的錯誤。
值不能為空。 參數名稱:connectionString
是我運行添加遷移“初始遷移”時的結果。
這是我在Startup.cs上的代碼
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddDbContext<LibraryContext>(options
=> options.UseSqlServer(Configuration.GetConnectionString("LibraryConnection")));
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseBrowserLink();
}
else
{
app.UseExceptionHandler("/Home/Error");
}
app.UseStaticFiles();
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
}
這是我在appsettings.json上的連接字符串
{
"ConnectionString": {
"LibraryConnection": "Server(localdb)\\MSSQLLocalDB;Database=Library_Dev;Trusted_Connection=True;MultipleActiveResultSets=true"
},
"Logging": {
"IncludeScopes": false,
"LogLevel": {
"Default": "Warning"
}
}
}
請注意,我有一個LibraryData項目(這是另一個項目),並且該類包含一個名為LibraryContext的類。
public class : DbContext
{
public LibraryContext(DbContextOptions options) : base(options) { }
public DbSet<Patron> Patrons { get; set; }
}
根據網上的資料和問題,我已經完成了所有工作,因此我似乎找不到我在做錯什么! 有人可以幫我嗎?
我認為您在appsettings.json中打了錯字ConnectionString應該是ConnectionStrings
{ "ConnectionStrings": { "LibraryConnection": "Server(localdb)\\\\MSSQLLocalDB;Database=Library_Dev;Trusted_Connection=True;MultipleActiveResultSets=true" }, "Logging": { "IncludeScopes": false, "LogLevel": { "Default": "Warning" } } }
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