Connecting to local SQL Server database from C# project

Question

I am running Visual Studio 2017 with SQL Server Object Explorer. I have been unable to connect to a local SQL database, although I copied the connection string directly from the SQL Server properties window. I created a tiny test project just to work on making this connection work, but nothing I try is working. Any suggestions would be greatly appreciated.

My Connection String:

(localdb)\MSSQLLocalDB;Initial Catalog=SportsStore;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False

Error I am receiving:

Keyword not supported: '(localdb)\mssqllocaldb;initial catalog'. at System.Data.Common.DbConnectionOptions.ParseInternal(Hashtable parsetable, String connectionString, Boolean buildChain, Hashtable synonyms, Boolean firstKey) at System.Data.Common.DbConnectionOptions..ctor(String connectionString, Hashtable synonyms, Boolean useOdbcRules) at System.Data.SqlClient.SqlConnectionString..ctor(String connectionString) at System.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous) at System.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(DbConnectionPoolKey key, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions) at System.Data.SqlClient.SqlConnection.ConnectionString_Set(DbConnectionPoolKey key) at System.Data.SqlClient.SqlConnection.set_ConnectionString(String value) at System.Data.SqlClient.SqlConnection..ctor(String connectionString, SqlCredential credential) at System.Data.SqlClient.SqlConnection..ctor(String connectionString) at TestWebApp_DotNetFramework.index.btnTestDBConn_Click(Object sender, EventArgs e) in c:\users...

That's not a valid connection string. You need something like `Server:`. — SLaks, Oct 23 '17 at 18:02
Thanks. I have corrected my connection string, and now I'm getting a 'better' error message - just need to go through other comments and see what *else* I'm doing wrong. Thanks again for your help! — user1549631, Oct 23 '17 at 18:22

score 1 · Accepted Answer · answered Oct 23 '17 at 18:07

1

You need to add Data Source attribute too. Your connection string should be like this.

Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=SportsStore;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False

answered Oct 23 '17 at 18:07

Serkan Arslan

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Thanks, don't know how I missed that! – user1549631 Oct 23 '17 at 18:26

score 0 · Answer 2 · answered Oct 23 '17 at 18:05

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I wouldn't copy/paste connection strings directly from MS SQL Server Studio. If you want to connect to LocalDB, then this post is going to help How to connect to LocalDb

answered Oct 23 '17 at 18:05

Mohammed Al Banna

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score 0 · Answer 3 · answered Oct 23 '17 at 18:19

Your error code says:

Keyword not supported: '(localdb)\mssqllocaldb;initial catalog'.

Which means that connection string parameter is mistype. if you want more information about connection string parameters, visit this link

try to add "Data Source = " in the begin of your string.

hope that help

Connecting to local SQL Server database from C# project

3 Answers3