Why do I get an error after adding connection string to code?

Question

The connection string which I have copied from Server Explorer in Visual Studio 2019 is

Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename="C:\\Users\\Lenovo\\Desktop\\dev\\C# .net\\Aadi Paw Plethysmometer\\Aadi Paw Plethysmometer\\bin\\Debug\\Database1.mdf";Integrated Security=True;Connect Timeout=30

Because there are some "" in the string, the code is returning an error.

This is the code:

string connectionstring =
    @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename="C:\Users\Lenovo\Desktop\dev\C# .net\Aadi Paw Plethysmometer\Aadi Paw Plethysmometer\bin\Debug\Database1.mdf";Integrated Security=True;Connect Timeout=30";

Answer 1

For plain strings escape double quotes with \\" .

string plain = "Double quote (\").";

For verbatim strings escape double quotes with "" .

string verbatim = @"Double quote ("").";

Note: it doesn't matter whether it is a connection string or not. From the C# perspective, this is just a string.

string connectionstring =
    @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=""C:\Users\Lenovo\Desktop\dev\C# .net\Aadi Paw Plethysmometer\Aadi Paw Plethysmometer\bin\Debug\Database1.mdf"";Integrated Security=True;Connect Timeout=30";