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SQL Parameter not updating table [closed]

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protected void btnSave_Click(object sender, EventArgs e)
{
string sql = #"UPDATE Users
SET Initials = #Ini
WHERE Common_Name = #cn";
using (var con = new SqlConnection("***"))
{
SqlCommand cmd = new SqlCommand(sql, con);
con.Open();
cmd.Parameters.AddWithValue("#cn", ddlUser.SelectedItem.Text);
cmd.Parameters.AddWithValue("#Ini", txtInitials.Text);
cmd.ExecuteNonQuery();
con.Close();
}
}
Not really quite sure what is going on, I am unable to get this to update the database.
The only way I was able to get this work was not using parameters and hard coding it which is not what I'm looking to do.
I can provide more code upon request, wasn't quite sure if it is necessary.

How to save and store the data in Azure SQL database using C# [closed]

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Closed 3 years ago.
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I am seeking help in storing and saving data in Azure SQL Database. Could anyone please help me with how I can code in C# or the libraries required to do the same

Update:
You can also use the following code, it's a simple .NET framework console project and all the needed assembly is added by default:
using System;
using System.Data.SqlClient;
namespace ConsoleApp13
{
class Program
{
static void Main(string[] args)
{
//define the connection string of azure database.
var cnString = "Server=tcp:xxx.database.windows.net,1433;Initial Catalog=xxx;Persist Security Info=False;User ID=xxx;Password=xxx;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;";
//define the insert sql command, here I insert data into the student table in azure db.
string cmdText = #"insert into student
(name,age)
values(#name, #age)";
using (SqlConnection con = new SqlConnection(cnString))
using (SqlCommand cmd = new SqlCommand(cmdText, con))
{
con.Open();
cmd.Parameters.AddWithValue("#name", "yang1");
cmd.Parameters.AddWithValue("#age", 20);
cmd.ExecuteNonQuery();
con.Close();
}
Console.WriteLine("completed***");
Console.ReadLine();
}
}
}
It can insert data successfully into azure database at my side. The screenshot as below:
The official doc provides all the CURD operations. Follow this doc to fetch azure sql database connection string, and set firewall.
The needed assembly is System.Data.dll, which should be added by default when create a project in visual studio.
The sample code is here. For save data, you can see this method static string Build_3_Tsql_Inserts() in this section Methods that return T-SQL statements.

I would request you to start with the Documentation and try the course Provision an Azure SQL database to store application data

Try working threw these.
A Example
Another Example

how to use a variable as the name of a database in C# [closed]

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Here is my problem. I need to have the user choose a server so I can have the program connect to that server (SQL NOTE This IS In C#)
This is what I have done, but I get an Exception
//first I make a variable that equals to a textbox text
//take the variable and I place it where I would put your sever name
//heres my code
string SQLC = (textBox1.Text);
con.ConnectionString = (#"Data Source=FORDS-PC;
Integrated Security=True;
Connect Timeout=15;
Encrypt=False;
TrustServerCertificate=False;
ApplicationIntent=ReadWrite;
MultiSubnetFailover=False");
here is the ERROR
An unhandled exception of type System.InvalidOperationException
occurred in System.Data.dll)
let me know if you need anything else that i need to tell you

You need to add the database to you connection string.
SQL Server connection string:
connectionString="Data Source=ServerName; Initial Catalog=DatabaseName;
User ID=UserName;Password=Password
Your code
string SQLC = textBox1.Text;
con.ConnectionString = ("Data Source=FORDS-PC;Initial Catalog="+SQLC+";Integrated Security=True;Connect
Timeout=15;Encrypt=False;TrustServerCertificate=False;
ApplicationIntent=ReadWrite;MultiSubnetFailover=False");`

Backup big size database time out error in SQL Server [closed]

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I try to backup my database but I get an error:
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
The backup or restore was aborted.
This is my code, and my database is up to 20GB in size.
string query = "Backup database Testing to disk='C:\Test.bak'"
con.Open();
cmd = new SqlCommand(query, con);
cmd.ExecuteNonQuery();
con.Close();
How can I change a timeout value in C# or query?

Use CommandTimeout property (Documentation), 0 means no limit.
Add
cmd.CommandTimeout = 0
to your code:
string query = "Backup database Testing to disk='C:\Test.bak'"
con.Open();
cmd = new SqlCommand(query, con);
cmd.CommandTimeout = 0;
cmd.ExecuteNonQuery();
con.Close();

How do I send strings of data to a SQL query? [closed]

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I have created a simple Username and Password login form in visual studio using c# which works great I then coded it so that whatever Username and Password was entered into the two textboxes was saved as a string... Now I want to pass those strings as parameters and store them into an SQL query... Any idea how I would go about doing this?

I would highly recommend NOT to store passwords as plain text. Instead look into hashed password methods.
Firstly you will need to specify a connection string. This can be done in the config file as:
<connectionStrings>
<add name="myConnectionString" connectionString="server=ServerAddress;database=myDb;uid=myUser;password=myPass;" />
</connectionStrings>
Now you want to read the connection string from your config file and you can do that in your C# code as:
string connectionString = ConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString;
I'm assuming you'll be inserting records. If you are going to update records, then you will need to change the query. For inserting records:
string myQuery = "INSERT INTO MyTable (UserNameColumn,PasswordColumn) VALUES (#UserName, #Password)";
Finally to execute the query and pass our parameters we can do
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand cmd = new SqlCommand(myQuery, connection))
{
cmd.Parameters.Add("#UserName", SqlDbType.NVarChar).Value = UserNameTextBox.Text;
cmd.Parameters.Add("#Password", SqlDbType.NVarChar).Value = PasswordTextBox.Text;
connection.Open();
cmd.ExecuteNonQuery();
}
}
Dont forget to include the namespace using System.Configuration;