sql，簡單查詢以從數據庫中刪除記錄

Question

我想以用戶輸入作為參數從我的firebird數據庫中刪除某些記錄。

所以我有以下代碼

private void btnOk_Click(object sender, EventArgs e)
        {
            string code = txtDeleteField.Text;
            string connString = ConfigurationManager.AppSettings["DemoAppConnectionString"];

            using (FbConnection conn = new FbConnection(connString))
            {
                using (FbCommand cmd = new FbCommand())
                {
                    cmd.CommandText = "DELETE * FROM DEMOAPP WHERE CODE= @P1";
                    cmd.Parameters.AddWithValue("@P1", code);
                    cmd.Connection = conn;
                    conn.Open();
                    cmd.Transaction = conn.BeginTransaction();

                    int a = cmd.ExecuteNonQuery();
                    if (a == 0)
                    {
                        MessageBox.Show("Error!");
                    }
                    else
                    {
                        MessageBox.Show("Record deleted, ok!" );
                    }
                }

            }
        }

此代碼產生錯誤

An unhandled exception of type 'FirebirdSql.Data.FirebirdClient.FbException' occurred in FirebirdSql.Data.FirebirdClient.dll

Additional information: Dynamic SQL Error
SQL error code = -104
Token unknown - line 1, column 8
*

Answer 1

您的查詢是錯誤的， "DELETE * FROM DEMOAPP WHERE CODE= @P1"無效： DELETE語句中不應存在* 。

將其更改為"DELETE FROM DEMOAPP WHERE CODE= @P1"應該可以解決此問題。