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_Do tNetFramework.index.btnTestDBConn_Click(Object sender, EventArgs e) in c:\\users...

Answer 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

Answer 2

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

Answer 3

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