How to attach mssql database using relative path?

Question

0.00/5 (No votes)

See more:

I would like to be able to attach the db using a relative path. Meaning that instead of using 'C:\Release\App_Data\TRTF_TagLogging.mdf', I should use '.\App_Data\TRTF_TagLogging.mdf'. Using '.\App_Data\TRTF_TagLogging.mdf', I get 'System.Data.SqlClient.SqlException (0x80131904): A file activation error occurred. The physical file name '.\App_Data\TRTF_TagLogging.mdf' may be incorrect.'
How could I do this?

What I have tried:

I am able to attach a mssql database on button click using this code:

using (SqlConnection connection = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=;Integrated Security=True; MultipleActiveResultSets = true")) 
            {
                using (SqlCommand cmd = new SqlCommand("", connection))
                {
                    using (SqlCommand cmd1 = new SqlCommand("", connection))
                    {
                        try
                        {
                            cmd.CommandText = "CREATE DATABASE [TRTF_TagLogging] ON (FILENAME ='C:\\Release\\App_Data\\TRTF_TagLogging.mdf'),(FILENAME ='C:\\Release\\App_Data\\App_Data\\TRTF_TagLogging_log.ldf') FOR ATTACH";

                            cmd1.CommandText = "if(exists(select * from sys.databases where name = 'TRTF_TagLogging')) PRINT 'DB attached'";

                            connection.Open();
                            cmd.ExecuteNonQuery();
                            cmd1.ExecuteNonQuery();
                            //the rest of the code

Posted 1-Apr-20 23:28pm

DrgIonuţ

Updated 2-Apr-20 0:09am

Add a Solution

2 solutions

Solution 1

The problem is that a relative path is just that: relative.
It's relative to the process that is trying to access the path - which in the case of a server based database engine such as SQL Server or MySql is not the process running your code.
So the path may be correct from the point of view of your software, but is unlikely to be correct from the POV of the server.
For this reason - among others - don't try to use a relative path. And definitely don't try to store databases in the same folder as your app, or a subfolder of that folder. It may work in dev, but in production it will fail mightily. There is also the fun and games that in production the server and client software are most likely to be on different machines, so the DB system almost certainly won't have any access to a local relative path at all!

You also shouldn't be use fixed connection strings, or trying to attach a DB in production code: the DB should be under the full control of the DB Server at all times or you will end up with multiple copies used by multiple users and teh whoel thing falls apart.

Posted 1-Apr-20 23:46pm

OriginalGriff

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

DrgIonuţ · Accepted Answer · 2020-04-02T00:10:00

I managed to solve it like this:

string path = Directory.GetCurrentDirectory();

cmd.CommandText = @"CREATE DATABASE [TRTF_TagLogging] ON (FILENAME ='" + path + @"\App_Data\TRTF_TagLogging.mdf'),(FILENAME ='" + path + @"\App_Data\TRTF_TagLogging_log.ldf') FOR ATTACH";

Directory.GetCurrentDirectory() returns C:\Release.