[SQL Server] A connection was successfully established with the server, but then an error occurred…

今天寫程式連結資料庫，遇見這樣的錯誤

環境 .NET Core 6 / VS 2022

資料來源： https://docs.microsoft.com/zh-tw/sql/connect/ado-net/sqlclient-troubleshooting-guide?view=sql-server-ver15

解決方法：DB連結字串 ConnectionString

以 appsettings.json 設定檔為例

“ConnectionStrings”: {
 “DefaultConnection”: “Server=.\\sqlexpress;Database=資料庫名稱;Trusted_Connection=True;TrustServerCertificate=true;MultipleActiveResultSets=true”
 },

相關的錯誤也都可以用上述相同解法

(1) Microsoft.Data.SqlClient.SqlException (0x80131904): A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: SSL Provider, error: 31 — Encryption(ssl/tls) handshake failed) System.IO.EndOfStreamException: End of stream reached

(2) A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error: 0 — The target principal name is incorrect.)

(3) Microsoft.Data.SqlClient.SqlException (0x80131904): Connection Timeout Expired. The timeout period elapsed during the post-login phase. The connection could have timed out while waiting for server to complete the login process and respond; Or it could have timed out while attempting to create multiple active connections. The duration spent while attempting to connect to this server was — [Pre-Login] initialization=837; handshake=394; [Login] initialization=3; authentication=15; [Post-Login] complete=1027; — -> System.ComponentModel.Win32Exception (258): Unknown error 258 at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction)

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