How To Create And Drop A Database Using C#

In this article, I am going to explain how you can create and drop a database, using C#. 

Creating database

This class is the control class, through which we are going to call the helper methods.

class Program
{
    private static ExecuteSql _executeMaster;
    private static string _connectionString = "Data Source=.;Integrated Security=SSPI;Initial Catalog=testme;Application Name=Manager.Test;Connection Timeout=300;
    User ID = sa;
    Password = password;
    ";
    private static string _masterDatabaseName = "master";
    static void Main(string[] args)
    {
        _executeMaster = new ExecuteSql(openConnectionToMaster);
        createDatabase("testme");
        Console.WriteLine("done");
        Console.ReadLine();
    }
    private static SqlConnection openConnectionToMaster()
    {
        var connectionStringBuilder = new SqlConnectionStringBuilder(_connectionString);
        connectionStringBuilder.InitialCatalog = _masterDatabaseName;
        var conn = new SqlConnection(connectionStringBuilder.ConnectionString);
        conn.Open();
        return conn;
    }
    private static void createDatabase(string databaseName)
    {
        //check if the DB exists or not
        if (!Exists(databaseName))
        {
            try
            {
                var script = File.ReadAllText("CreateDB.sql");
                script = ReplaceScriptTags(script, databaseName);
                _executeMaster.ExecuteTransactionlessNonQuery(script, 10800);
            } catch (Exception exception)
            {
                string msg = exception.StackTrace;
            }
        }
    }
    private static string ReplaceScriptTags(string script, string name)
    {
        script = script.Replace("$(DBNAME)", name);
        return script;
    }
    public static bool Exists(string databaseName)
    {
        return
        Convert.ToBoolean(_executeMaster.ExecuteScalar("SELECT database_id FROM sys.databases WHERE Name = @databaseName", parameters: new Dictionary & lt; string, object & gt; {
            {
                "@databaseName",
                databaseName
            }
        }));
    }
    public static void Drop(string databaseName)
    {
        _executeMaster.ExecuteTransactionlessNonQuery(string.Format("DROP DATABASE [{0}]", databaseName), 120);
    }
    public static void SetOnline(string databaseName)
    {
        _executeMaster.ExecuteTransactionlessNonQuery(string.Format("ALTER DATABASE [{0}] SET ONLINE", databaseName));
    }
}

This class is the helper class being used. We will use this class to execute the script.

public class ExecuteSql
{
    private readonly Func & lt;
    SqlConnection & gt;
    _openConnection;
    public ExecuteSql(Func & lt; SqlConnection & gt; openConnection)
    {
        _openConnection = openConnection;
    }
    public void ExecuteCustom(Action & lt; SqlConnection & gt; action)
    {
        using(var connection = _openConnection())
        {
            action(connection);
        }
    }
    public int ExecuteScalar(string sql, int timeout = 30, IDictionary & lt; string, object & gt; parameters = null)
    {
        parameters = parameters ? ? new Dictionary & lt;
        string, object & gt;
        ();
        var result = 0;
        using(var connection = _openConnection())
        {
            using(var transaction = connection.BeginTransaction())
             {
                using(var command = connection.CreateCommand())
                    {
                    command.Transaction = transaction;
                    foreach(var parameter in parameters)
                      {
                        command.Parameters.AddWithValue(parameter.Key, parameter.Value);
                    }
                    command.CommandTimeout = timeout;
                    {
                        command.CommandText = sql;
                        command.CommandType = CommandType.Text;
                        result = (int)(command.ExecuteScalar() ? ?
                            default (int));
                    }
                    transaction.Commit();
                }
            }
        }
        return result;
    }
    public void ExecuteTransactionlessNonQuery(string sql, int timeout = 30)
        {
        using(var connection = _openConnection())
        {
            using(var command = connection.CreateCommand())
            {
                command.CommandType = CommandType.Text;
                command.CommandTimeout = timeout;
                command.CommandText = sql;
                command.ExecuteNonQuery();
            }
        }
    }
    public void ExecuteNonQuery(string sql, int timeout = 30, IDictionary & lt; string, object & gt; parameters = null)
        {
        parameters = parameters ? ? new Dictionary & lt;
        string, object & gt;
        ();
        using(var connection = _openConnection())
        {
            using(var transaction = connection.BeginTransaction())
            {
                using(var command = connection.CreateCommand())
                 {
                    command.Transaction = transaction;
                    command.CommandTimeout = timeout;
                    {
                        command.Parameters.Clear();
                        foreach(var parameter in parameters)
                      {
                            if (sql.Contains(parameter.Key))
                           {
                                command.Parameters.AddWithValue(parameter.Key, parameter.Value);
                            }
                        }
                        command.CommandText = sql;
                        command.CommandType = CommandType.Text;
                        command.ExecuteNonQuery();
                    }
                    transaction.Commit();
                }
            }
        }
    }
}

This is the script file that is used to create the script. The script is well commented, so that you can see the details of the Application. You need to place this script in a file, called CreateDB.sql and save it in the current directory.

BEGIN TRY
/*==============================================
Prepare statements according to server settings
and given input
==============================================*/
-- DECLARES
DECLARE @rc int
DECLARE @DataDir nvarchar(4000)
DECLARE @LogDir nvarchar(4000)
DECLARE @LogFileName nvarchar(4000)
DECLARE @DataFileName nvarchar(4000)
DECLARE @CMD nvarchar(4000)
-- Read reg values to get default datapath
EXEC @rc = master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE',N'Software\Microsoft\MSSQLServer\MSSQLServer',N'DefaultData', @DataDir output, 'no_output'
-- Check if value is NULL. In that case no changes has been done to default setup. Read from SQLDataRoot instead
IF (@DataDir is null)
BEGIN
EXEC @rc = master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE',N'Software\Microsoft\MSSQLServer\Setup',N'SQLDataRoot', @DataDir output, 'no_output'
SELECT @DataDir = @DataDir + N'\Data'
END
-- Read reg values to get default logpath
EXEC @rc = master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE',N'Software\Microsoft\MSSQLServer\MSSQLServer',N'DefaultLog', @LogDir output, 'no_output'
-- Check if value is NULL. In that case no changes has been done to default setup. Read from SQLDataRoot instead
IF (@LogDir is null)
BEGIN
EXEC @rc = master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE',N'Software\Microsoft\MSSQLServer\Setup',N'SQLDataRoot', @LogDir output, 'no_output'
SELECT @LogDir = @LogDir + N'\Data'
END
-- Add filenames to the folders
SET @DataFileName = @DataDir + '\$(DBNAME)_Data.mdf'
SET @LogFileName = @LogDir + '\$(DBNAME)_Log.ldf'
-- Prepare statement
SELECT @CMD =
'CREATE DATABASE $(DBNAME)
ON
(
NAME = $(DBNAME)_Data,
FILENAME = ''' + @DataFileName + ''',
SIZE = 50,
FILEGROWTH = 10
)
LOG ON (
NAME = $(DBNAME)_Log,
FILENAME = ''' + @LogFileName + ''',
SIZE = 100,
FILEGROWTH = 20
)
'
/*==============================================
This is were the action starts
==============================================*/
PRINT 'Adding database $(DBNAME). Working...'
-- Create database
EXEC (@CMD)
PRINT 'Adding database $(DBNAME). Finished!'
PRINT 'Adding settings and properties for $(DBNAME). Working...'
-- Add DBTYPE as extended property
EXEC $(DBNAME).sys.sp_addextendedproperty @name=N'DatabaseType', @value=N''
--Disable fulltext
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
BEGIN
EXEC $(DBNAME).[dbo].[sp_fulltext_database] @action = 'disable'
END
-- Set recovery model
ALTER DATABASE $(DBNAME) SET RECOVERY FULL
ALTER DATABASE $(DBNAME) SET MULTI_USER
--All other database settings are based on the "model" database in local instance
--see: sp_configure
-- Set owner = sa (cosmetics only)
EXEC $(DBNAME).dbo.sp_changedbowner @loginame = N'sa', @map = false
PRINT 'Adding settings and properties for $(DBNAME). Finished'
END TRY
BEGIN CATCH
DECLARE @ErrorMessage NVARCHAR(4000)
DECLARE @ErrorNumber INT
DECLARE @ErrorSeverity INT
DECLARE @ErrorState INT
DECLARE @ErrorLine INT
IF ERROR_NUMBER() IS NOT NULL
BEGIN
SET @ErrorNumber = ERROR_NUMBER()
SET @ErrorSeverity = ERROR_SEVERITY()
SET @ErrorState = ERROR_STATE()
SET @ErrorLine = ERROR_LINE()
-- Return an error with state 127 since it will abort SQLCMD
SET @ErrorMessage = 'Error %d, Severity %d, State %d, Line %d, Message: '+ ERROR_MESSAGE()
RAISERROR (@ErrorMessage, 16, 127, @ErrorNumber, @ErrorSeverity, @ErrorState, @ErrorLine)
END
END CATCH
PRINT 'Finished'
/*******************************************************************************/

Dropping database

Now this time, we will drop a DB. I have divided the code into two classes. Let's see them in detail.

The first class is the control class through which we will call the helpers. In the code, given below, first, we will try to connect to the master DB. In the drop database method, we need to check if the DB exists or not and if it does, we will need to set the DB online. The reason to set the DB online is when you drop the DB, the file on the disk will also be deleted.

class Program
{
    private static ExecuteSql _executeMaster;
    private static string _connectionString = "Data Source=.;Integrated Security=SSPI;Initial Catalog=testme;Application Name=Manager.Test;Connection Timeout=300;
    User ID = sa;
    Password = password;
    ";
    private static string _masterDatabaseName = "master";
    static void Main(string[] args)
    {
        _executeMaster = new ExecuteSql(openConnectionToMaster);
        dropDatabase("testme");
        Console.WriteLine("done");
        Console.ReadLine();
    }
    private static SqlConnection openConnectionToMaster()
    {
        var connectionStringBuilder = new SqlConnectionStringBuilder(_connectionString);
        connectionStringBuilder.InitialCatalog = _masterDatabaseName;
        var conn = new SqlConnection(connectionStringBuilder.ConnectionString);
        conn.Open();
        return conn;
    }
    private static void dropDatabase(string databaseName)
    {
        if (Exists(databaseName))
        {
            SetOnline(databaseName); // if dropping a database that is offline, the file on disk will remain!
            _executeMaster.ExecuteTransactionlessNonQuery(string.Format("ALTER DATABASE [{0}] SET SINGLE_USER WITH ROLLBACK IMMEDIATE;", databaseName));
            Drop(databaseName);
        }
    }
    public static bool Exists(string databaseName)
    {
        return
        Convert.ToBoolean(_executeMaster.ExecuteScalar("SELECT database_id FROM sys.databases WHERE Name = @databaseName", parameters: new Dictionary & lt; string, object & gt; {
            {
                "@databaseName",
                databaseName
            }
        }));
    }
    public static void Drop(string databaseName)
    {
        _executeMaster.ExecuteTransactionlessNonQuery(string.Format("DROP DATABASE [{0}]", databaseName), 120);
    }
    public static void SetOnline(string databaseName)
    {
        _executeMaster.ExecuteTransactionlessNonQuery(string.Format("ALTER DATABASE [{0}] SET ONLINE", databaseName));
    }
}

Now, you need to replace the user Id and password.