添加命令数据验证和其他杂项修改

QRCodeService/Application/Queries/LinkQueries.cs

@@ -6,6 +6,7 @@ using System.Text;
 using System.Threading.Tasks;
 using Dapper;
 using MySqlConnector;
+using Microsoft.Extensions.Configuration;
 
 namespace QRCodeService.Application.Queries
 {
@@ -13,9 +14,9 @@ namespace QRCodeService.Application.Queries
     {
         readonly string _connectionString;
 
-        public LinkQueries(string connectionString)
+        public LinkQueries(IConfiguration configuration)
         {
-            _connectionString = connectionString;
+            _connectionString = configuration.GetConnectionString("default");
         }
 
         public async Task<Link> GetLinkAsync(string shortCode)