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Store user-specific connection strings for later use in ASP.NET Web API

I am working on complicated project which allows every client to set their connection string information to connect to their own database but after that I didn't now what to do or how to let the client reach his own connection string (I don't have a table to save the connection string I want to be dynamic).
Is there any way to store the connection string in config page for every client and read those page in my web config.

If number of client is managable, then you store it in web config file and you need seperate dbContext implentation if everyones database is different. If same db design is same for all, you can store credentials in dictionary and dynamically prepare connection string run time and connect.
Here is an example for MSSQL (I assume you are not using EF)
Not need to store connectionstring in web config.
Prepare connection string. You can store user wise parameters in DB as well.
public string BuildConnectionString(string dataSource, string dbName, string userId, string password,
string persistSecurityInfo, string encrypt, string trustServerCertificate, string applicationIntent, string multiSubnetFailover)
{
return $"Data Source = {dataSource}; Initial Catalog = {dbName}; User ID = {userId}; Password = {password}; " +
$"Persist Security Info = {persistSecurityInfo}; Encrypt = {encrypt}; TrustServerCertificate = {trustServerCertificate};" +
$" ApplicationIntent = {applicationIntent}; MultiSubnetFailover ={multiSubnetFailover}";
}
DB Connection example:
void CheckDbConnection()
{
string connetionString = BuildConnectionString("WIN-50GP30FGO75", // or IP
"Demodb", "YourUserID", "YourPassword", "True", "False", "False",
"ReadWrite", "False");
string sql = "Select TutorialID,TutorialName from table1";
using (SqlConnection cnn = new SqlConnection(connetionString))
{
using (SqlCommand command = new SqlCommand(sql, cnn))
{
cnn.Open();
dataReader = sqlquery.ExecuteReader();
while (dataReader.Read())
{
Output = Output + dataReader.GetValue(0) + "-" +
dataReader.GetValue(1) + "</br>";
}
Console.Write(Output);
cnn.Close();
}
}
}

You wont be able overwrite or add something to the Web.config during runtime, only read from it.The web.config file is only read once during startup and wont be used afterwards.
A suggestiong to overcome this is either store the connectionstring for your customers in your own database or store them somewhere else. I prefer using Azure KeyVault for these things, as it allows you to let the user change the data using a specific key.
Also this is one of those scenarios where security is a big factor, so you must be very carefull when giving your customers these kinds of actions.

Method fires an exception when trying to connect to remote SQL Server

I want to create a simple tool that connect to SQL Server then list all databases, and after user selects one of those databases, the tool will perform some SQL scripts on it.
Below is a method that should return a DataTable contains all my databases;
I send to it sqlServerIp as first parameter like 10.10.20.30 ip address not server name.
Also I didn't specify a SQL Server instance.
private DataTable GetSqlServerDatabases(String sqlServer, bool isWindowsAuth, String login, String password)
{
String connectionString;
DataTable databases;
if (isWindowsAuth)
{
connectionString = "Data Source=" + sqlServer + ",1433;Network Library=DBMSSOCN; Integrated Security=True;";
}
else
{
connectionString = "Data Source=" + sqlServer + ",1433;Network Library=DBMSSOCN;" + "User id=" + login + ";Password=" + password + ";";
}
try
{
using (var con = new SqlConnection(connectionString))
{
con.Open();
databases = con.GetSchema("Databases");
foreach (DataRow database in databases.Rows)
{
String databaseName = database.Field<String>("database_name");
short dbID = database.Field<short>("dbid");
DateTime creationDate = database.Field<DateTime>("create_date");
}
}
}
catch(Exception ex)
{
databases = null;
MessageBox.Show(ex.Message.ToString());
}
return databases;
}
When I try to call the method on more than one server I faced an exception:
Login failed. The login is from an untrusted domain and cannot be used with Windows authentication.
or
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.
I used connection string with Network Library=DBMSSOCN; after searching here on SO and web so I don't know what is the wrong with this method.

Remove Integrated Security parameter. This parameter is for trusted connections.
More samples on http://www.connectionstrings.com/sql-server

How to connect W10 Universal App with MySQL database

I'm writing my first Windows 10 Universal App that operates on MySql database. I used code from this guide (It's for Windows 8 store apps):
https://blogs.oracle.com/MySqlOnWindows/entry/how_to_using_connector_net
But when I try to open connection with my database I get error:
An exception of type 'System.NotImplementedException' occurred in >MySql.Data.RT.dll but was not handled in user code
Additional information: SSL not supported in this WinRT release.
public class DBconnector
{
static string server = "127.0.0.1";
static string database = "hurtownia";
static string user = "root";
static string pswd = "root";
public static bool login(string email, string password)
{
string connectionString = "Server = " + server + ";database = " + database + ";uid = " + user + ";password = " + pswd + ";";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand checkLogin = new MySqlCommand("select password_hash, password_salt from users where email = \""+email+"\"",connection);
using (MySqlDataReader reader = checkLogin.ExecuteReader())
{
reader.Read();
string hash = reader.GetString("password_hash");
string salt = reader.GetString("password_salt");
bool result = passwordGenerator.compare(password, hash, salt);
if (result)
return true;
else
return false;
}
}
}
}
So, my question is how to fix that and correctly connect to MySql database in Windows 10 Universal App.

Add ";SslMode=None" to your connection string

I'm afarid the SSL connection is not supported by MySql WinRT connector. You have to disable the SSL connection from the MySql server.
Chapter 8 Connector/Net Support for Windows Store
Connector/Net RT does not support SSL connections or Windows
authentication. Also, SHA256 is not currectly supported.
6.3.6.4 SSL Command Options
BTW, another alternative way to retrieve the data from mysql is host a REST service:
App -> Rest Service -> MySQL

SQL query running as local user instead of user in connection string

I have a WPF application that accesses a SQL server using SqlConnection with a connection string.
private string connString =
"user id=*****;" +
"password=*****;" +
"server=1.1.1.1;" +
"Trusted_Connection = yes;" +
"database=****;" +
"connection timeout = 30";
private SqlConnection myConnection = new SqlConnection(connString);
The string contains the username and password for the account I want the program to use to access the database. This works as I would expect it to on my machine. Once I run it on another machine I get a an error:
"Login failed for user 'Domain\local user'"
I am sure that I am just missing some sort of setting or configuration.
Any help would be great

Trusted_Connection = yes tells SQL Server to use Integrated (Windows) Authentication. Your user name and password are ignored.

connect mysql database in websever with c# application

i have a PHP website and MySQL database in same web sever. i wont to connect that MySQL database with c# application. my c# application in run another computer.
how can i connect that MySQL database ?

First make sure you have downloaded and installed the MySQL Connector/NET from the MySQL official website. In this article, I will use the Connector/NET version 6.1.
Then add MySql.Data namespace in Reference
Then you can use mysql in .net
now create a connection strin like this
class ConnectToMySql{
private MySqlConnection connection;
private void Initialize()
{
server = "localhost";
database = "connectcsharptomysql";
uid = "username";
password = "password";
string connectionString;
connectionString = "SERVER=" + server + ";" + "DATABASE=" +
database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
connection.Open();
}
}
Then
1 Create a MySQL command.
2 Assign a connection and a query to the command. This can be done using the constructor
3 using the Connection and the CommandText methods in the MySqlCommand class.
4 Create a MySqlDataReader object to read the selected records/data.
5 Execute the command.
6 Read the records and display them or store them in a list.
7 Close the data reader.
8 Close the connection.
I tooth this will help full for you . now you can start working on mysql in .NET
Best of luck

you firstly have to add mysql ref to your project:
plz right click on your project and go to the ref part in it
after that try to find mysl.conncetor and tick it
and refresh your project and firstly try to add using mysql.net.client
now you can use data base located in the mysql db from c# coding
be sure you have downloaded both mysql connector and installaton which is about 500 mb files.
class ConnectToMySql{
private MySqlConnection mscon;
private void Initialize()
{
server = "localhost";
database = "your own database name";
uid = " your username";
password = "your password";
string const;
connectionString = "SERVER=" + server + ";" + "DATABASE=" +
database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
mscon= new MySqlConnection(const);
mscon.Open();
}
}