Variable Used In DataSource C#

Question

I have the following code but it seems to not connect, just wondering whether i'm referring to the variable wrong?

sqlConnectionNW.ConnectionString = "Data Source=@server;Initial Catalog=Northwind;Integrated Security=True";

When I change it to:

sqlConnectionNW.ConnectionString = "Data Source=ISSP\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True";

It works fine. It's just when I change it to the variable 'server'.

Answer 1

It would be more like this:

string mySQLServer = "ISSP\SQLEXPRESS";

sqlConnectionNW.ConnectionSTring = "Data Source=" + mySQLServer + ";Initial Catalog=Northwind;Integrated Security=True";

Answer 2

You can't have a variable like that in the connection string. You need to do any replacements before using the connection string.

Answer 3

你可以使用string.format（），这将允许你使用变量

sqlConnectionNW.ConnectionString = string.format("Data Source={0};Initial Catalog=Northwind;Integrated Security=True",server)

Answer 4

You maybe better off using the SqlConnectionStringBuilder class Sql Connection String Builder

This may allow you to generate the connection string in way more meaningful to you

Answer 5

当你在“”之间写一些东西时，它被识别为一个字符串，要使用一个变量，你必须在它之外写一个变量，并在它之前加一个+。如果有一些变量或字符串落后，你必须使用另一个+在您的变量之后。

"Data Source=" +variblename+ ";Initial Catalog=Northwind;Integrated Security=True"