Deleting database from C#

Question

I have an MDF file that I\'m attaching to my local SQL server during testing with MSTEST and I don\'t want to have to go delete those temporary databases by hand after I\'ve

Answer 1

I. Create Resources file (Resources.rsx) and write sql queries:

• SQL_KillConnections

---

DECLARE @DatabaseName nvarchar(50)
SET @DatabaseName = N'{0}'
DECLARE @SQL varchar(max)
SELECT @SQL = COALESCE(@SQL,'') + 'Kill ' + Convert(varchar, SPId) + ';'
FROM MASTER..SysProcesses
WHERE DBId = DB_ID(@DatabaseName) AND SPId <> @@SPId
EXEC(@SQL)

• SQL_DropDatabaseIfExists

---

IF EXISTS(select * from sys.databases where name='{0}')
DROP DATABASE [{0}]

II. Add MsSqlDatabaseTestsHelper class into the test project

public class MsSqlDatabaseTestsHelper
{
    private readonly string _connectionString;

    public MsSqlDatabaseTestsHelper(string connectionString)
    {
        _connectionString = connectionString;
    }

    private void ExecuteNonQuery(string sql)
    {
        using (var connection = new SqlConnection(_connectionString))
        {
            connection.Open();
            SqlCommand command = connection.CreateCommand();
            command.CommandText = sql;
            command.ExecuteNonQuery();
        }
    }

    public void CreateDatabase(string databaseName)
    {
        ExecuteNonQuery("CREATE DATABASE {0}".Set(databaseName));
    }

    public void DropDatabase(string databaseName)
    {
        try
        {
            ExecuteNonQuery(Resources.SQL_KillConnections
                .Set(databaseName));
        }
        catch (Exception)
        {
            throw new Exception("Can't kill database '{0}' connections"
                .Set(databaseName));
        }

        try
        {
            ExecuteNonQuery(Resources.SQL_DropDatabaseIfExists
                .Set(databaseName));
        }
        catch (Exception)
        {
            throw new Exception("Can't drop database '{0}'"
                .Set(databaseName));
        }
    }
}

III. Use database helper in your unit tests

[TestFixture]
public class CmsPageRepositoryTests
{
    private readonly MsSqlDatabaseTestsHelper _msSqlDatabaseTestsHelper = 
        new MsSqlDatabaseTestsHelper(ConnectionStringWithoutDatabase);

    private const string ConnectionStringWithoutDatabase = 
        @"server=.\SqlExpress;uid=sa;pwd=1;";

    private const string DatabaseName = "TestPersistence";

    [SetUp]
    public void SetUp()
    {
        _msSqlDatabaseTestsHelper.DropDatabase(DatabaseName);
        _msSqlDatabaseTestsHelper.CreateDatabase(DatabaseName);
    }

    [TearDown]
    public void TearDown()
    {
        _msSqlDatabaseTestsHelper.DropDatabase(DatabaseName);
    }

    [Test]
    public void TestSomethingWithDatabaseUsing()
    {
    }
}