使用LocalDB进行集成测试

Question

In order to write integration tests against some data access code for my application, I've written an abstract class to use for the database integration tests .

It creates a fresh instance of the database using LocalDB then tears it down once complete.

However for some reason, the DROP DATABASE command always fails with the following exception:

Cannot drop database "Integration_DataAccess" because it is currently in use.

Why is this? Is there a better approach for using LocalDB for integration database testing?

Below is the code for my abstract database integration testing class:

using System;
using ProjectName.DataAccess.EmailSubscription;
using Microsoft.SqlServer.Management.Common;
using Microsoft.SqlServer.Management.Smo;
using NUnit.Framework;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.IO;

namespace ProjectName.DataAccess.Tests.IntegrationTests
{
    public abstract class IntegrationTestBase
    {
        private const string DatabaseConnNameEmpty = "DbDSNEmpty";
        private const string DatabaseConnName = "DbDSN";

        private const string DatabaseName = "Integration_DataAccess";

        [TestFixtureSetUp]
        public void SetupTempDatabase()
        {
            // Create database (drop first, just in case)
            var connection =new SqlConnection(ConfigurationManager.ConnectionStrings[DatabaseConnNameEmpty].ConnectionString);
            var server = new Server(new ServerConnection(connection));

            server.ConnectionContext.ExecuteNonQuery( string.Format(  "IF EXISTS(select * from sys.databases where name='{0}') DROP DATABASE [{0}]", DatabaseName));
            server.ConnectionContext.ExecuteNonQuery(string.Format("CREATE DATABASE {0}", DatabaseName));

            // Run database creation script
            using (var sr = new StreamReader(@"IntegrationTests\DatabaseSetup.txt"))
            {
                var sql = sr.ReadToEnd();
                ExecuteNonQuery(sql);
            }
        }

        [TestFixtureTearDown]
        public void RemoveTempDatabase()
        {
            // Drop database
            ExecuteNonQuery(string.Format("DROP DATABASE [{0}]", DatabaseName));
        }

        #region private methods

        protected static void ExecuteNonQuery(string sql)
        {
            // Thanks to http://weblogs.asp.net/jgalloway/archive/2006/11/07/Handling-_2200_GO_2200_-Separators-in-SQL-Scripts-_2D00_-the-easy-way.aspx
            var connection = new SqlConnection(ConnectionString());
            var server = new Server(new ServerConnection(connection));
            server.ConnectionContext.ExecuteNonQuery(sql);
            connection.Close();
        }

        protected static string ConnectionString()
        {
            return ConfigurationManager.ConnectionStrings[DatabaseConnName].ConnectionString;
        }

        protected static DataTable Select(string sql)
        {
            using (var conn = new SqlConnection(ConnectionString()))
            {
                var adapter = new SqlDataAdapter(sql, conn);
                var data = new DataTable();
                adapter.Fill(data);
                return data;
            }
        }

        protected static int ExecuteScalar(string sql)
        {
            using (var conn = new SqlConnection(ConnectionString()))
            {
                var cmd = new SqlCommand(sql, conn);
                conn.Open();
                int result = (int)cmd.ExecuteScalar();
                conn.Close();
                return result;
            }
        }

        #endregion
    }
}

Answer 1

That's because the connection you have open is to the database you want to drop.

You need to USE MASTER first.

See this article http://blog.sqlauthority.com/2007/12/07/sql-server-fix-error-3702-cannot-drop-database-because-it-is-currently-in-use/