} // NewDrive
/// <summary>
/// Removes a drive from the provider.
/// </summary>
/// <param name="drive">The drive to remove.</param>
/// <returns>The drive removed.</returns>
protected override PSDriveInfo RemoveDrive(PSDriveInfo drive)
{
// check if drive object is null
if (drive == null)
{
WriteError(new ErrorRecord(
new ArgumentNullException("drive"),
"NullDrive",
ErrorCategory.InvalidArgument,
drive)
);
return(null);
}
// close ODBC connection to the drive
AccessDBPSDriveInfo accessDBPSDriveInfo = drive as AccessDBPSDriveInfo;
if (accessDBPSDriveInfo == null)
{
return(null);
}
accessDBPSDriveInfo.Connection.Close();
return(accessDBPSDriveInfo);
} // RemoveDrive
} // TableNameIsValid
/// <summary>
/// Checks to see if the specified table is present in the
/// database
/// </summary>
/// <param name="tableName">Name of the table to check</param>
/// <returns>true, if table is present, false otherwise</returns>
private bool TableIsPresent(string tableName)
{
// using ODBC connection to the database and get the schema of tables
AccessDBPSDriveInfo di = this.PSDriveInfo as AccessDBPSDriveInfo;
if (di == null)
{
return(false);
}
OdbcConnection connection = di.Connection;
DataTable dt = connection.GetSchema("Tables");
// check if the specified tableName is available
// in the list of tables present in the database
foreach (DataRow dr in dt.Rows)
{
string name = dr["TABLE_NAME"] as string;
if (name.Equals(tableName, StringComparison.OrdinalIgnoreCase))
{
return(true);
}
}
WriteError(new ErrorRecord(
new ArgumentException("Specified Table is not present in database"), "TableNotAvailable",
ErrorCategory.InvalidArgument, tableName));
return(false);
}// TableIsPresent
/// <summary>
/// Retrieve the list of tables from the database.
/// </summary>
/// <returns>
/// Collection of DatabaseTableInfo objects, each object representing
/// information about one database table
/// </returns>
private Collection <DatabaseTableInfo> GetTables()
{
Collection <DatabaseTableInfo> results =
new Collection <DatabaseTableInfo>();
// using ODBC connection to the database and get the schema of tables
AccessDBPSDriveInfo di = this.PSDriveInfo as AccessDBPSDriveInfo;
if (di == null)
{
return(null);
}
OdbcConnection connection = di.Connection;
DataTable dt = connection.GetSchema("Tables");
int count;
// iterate through all rows in the schema and create DatabaseTableInfo
// objects which represents a table
foreach (DataRow dr in dt.Rows)
{
String tableName = dr["TABLE_NAME"] as String;
DataColumnCollection columns = null;
// find the number of rows in the table
try
{
String cmd = "Select count(*) from \"" + tableName + "\"";
OdbcCommand command = new OdbcCommand(cmd, connection);
count = (Int32)command.ExecuteScalar();
}
catch
{
count = 0;
}
// create DatabaseTableInfo object representing the table
DatabaseTableInfo table =
new DatabaseTableInfo(dr, tableName, count, columns);
results.Add(table);
} // foreach (DataRow...
return(results);
} // GetTables
/// <summary>
/// Create a new drive. Create a connection to the database file and set
/// the Connection property in the PSDriveInfo.
/// </summary>
/// <param name="drive">
/// Information describing the drive to add.
/// </param>
/// <returns>The added drive.</returns>
protected override PSDriveInfo NewDrive(PSDriveInfo drive)
{
// check if drive object is null
if (drive == null)
{
WriteError(new ErrorRecord(
new ArgumentNullException("drive"),
"NullDrive",
ErrorCategory.InvalidArgument,
null)
);
return(null);
}
// check if drive root is not null or empty
// and if its an existing file
if (String.IsNullOrEmpty(drive.Root) || (File.Exists(drive.Root) == false))
{
WriteError(new ErrorRecord(
new ArgumentException("drive.Root"),
"NoRoot",
ErrorCategory.InvalidArgument,
drive)
);
return(null);
}
// create a new drive and create an ODBC connection to the new drive
AccessDBPSDriveInfo accessDBPSDriveInfo = new AccessDBPSDriveInfo(drive);
OdbcConnectionStringBuilder builder = new OdbcConnectionStringBuilder();
builder.Driver = "Microsoft Access Driver (*.mdb)";
builder.Add("DBQ", drive.Root);
OdbcConnection conn = new OdbcConnection(builder.ConnectionString);
conn.Open();
accessDBPSDriveInfo.Connection = conn;
return(accessDBPSDriveInfo);
} // NewDrive
/// <summary>
/// Create a new drive. Create a connection to the database file and set
/// the Connection property in the PSDriveInfo.
/// </summary>
/// <param name="drive">
/// Information describing the drive to add.
/// </param>
/// <returns>The added drive.</returns>
protected override PSDriveInfo NewDrive(PSDriveInfo drive)
{
// check if drive object is null
if (drive == null)
{
WriteError(new ErrorRecord(
new ArgumentNullException("drive"),
"NullDrive",
ErrorCategory.InvalidArgument,
null)
);
return null;
}
// check if drive root is not null or empty
// and if its an existing file
if (String.IsNullOrEmpty(drive.Root) || (File.Exists(drive.Root) == false))
{
WriteError(new ErrorRecord(
new ArgumentException("drive.Root"),
"NoRoot",
ErrorCategory.InvalidArgument,
drive)
);
return null;
}
// create a new drive and create an ODBC connection to the new drive
AccessDBPSDriveInfo accessDBPSDriveInfo = new AccessDBPSDriveInfo(drive);
OdbcConnectionStringBuilder builder = new OdbcConnectionStringBuilder();
builder.Driver = "Microsoft Access Driver (*.mdb)";
builder.Add("DBQ", drive.Root);
OdbcConnection conn = new OdbcConnection(builder.ConnectionString);
conn.Open();
accessDBPSDriveInfo.Connection = conn;
return accessDBPSDriveInfo;
} // NewDrive
} // GetTable
/// <summary>
/// Obtain a data adapter for the specified Table
/// </summary>
/// <param name="tableName">Name of the table to obtain the
/// adapter for</param>
/// <returns>Adapter object for the specified table</returns>
/// <remarks>An adapter serves as a bridge between a DataSet (in memory
/// representation of table) and the data source</remarks>
private OdbcDataAdapter GetAdapterForTable(string tableName)
{
OdbcDataAdapter da = null;
AccessDBPSDriveInfo di = this.PSDriveInfo as AccessDBPSDriveInfo;
if (di == null || !TableNameIsValid(tableName) || !TableIsPresent(tableName))
{
return(null);
}
OdbcConnection connection = di.Connection;
try
{
// Create a odbc data adpater. This can be sued to update the
// data source with the records that will be created here
// using data sets
string sql = "Select * from " + tableName;
da = new OdbcDataAdapter(new OdbcCommand(sql, connection));
// Create a odbc command builder object. This will create sql
// commands automatically for a single table, thus
// eliminating the need to create new sql statements for
// every operation to be done.
OdbcCommandBuilder cmd = new OdbcCommandBuilder(da);
// Open the connection if its not already open
if (connection.State != ConnectionState.Open)
{
connection.Open();
}
}
catch (Exception e)
{
WriteError(new ErrorRecord(e, "CannotAccessSpecifiedTable",
ErrorCategory.InvalidOperation, tableName));
}
return(da);
} // GetAdapterForTable
