} // RemoveDrive
#endregion Drive Manipulation
#region Item Methods
/// <summary>
/// Retrieves an item using the specified path.
/// </summary>
/// <param name="path">The path to the item to return.</param>
protected override void GetItem(string path)
{
// check if the path represented is a drive
if (PathIsDrive(path))
{
WriteItemObject(this.PSDriveInfo, path, true);
return;
}// if (PathIsDrive...
// Get table name and row information from the path and do
// necessary actions
string tableName;
int rowNumber;
PathType type = GetNamesFromPath(path, out tableName, out rowNumber);
if (type == PathType.Table)
{
DatabaseTableInfo table = GetTable(tableName);
WriteItemObject(table, path, true);
}
else if (type == PathType.Row)
{
DatabaseRowInfo row = GetRow(tableName, rowNumber);
WriteItemObject(row, path, false);
}
else
{
ThrowTerminatingInvalidPathException(path);
}
} // GetItem
/// <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
} // SetItem
/// <summary>
/// Test to see if the specified item exists.
/// </summary>
/// <param name="path">The path to the item to verify.</param>
/// <returns>True if the item is found.</returns>
protected override bool ItemExists(string path)
{
// check if the path represented is a drive
if (PathIsDrive(path))
{
return(true);
}
// Obtain type, table name and row number from path
string tableName;
int rowNumber;
PathType type = GetNamesFromPath(path, out tableName, out rowNumber);
DatabaseTableInfo table = GetTable(tableName);
if (type == PathType.Table)
{
// if specified path represents a table then DatabaseTableInfo
// object for the same should exist
if (table != null)
{
return(true);
}
}
else if (type == PathType.Row)
{
// if specified path represents a row then DatabaseTableInfo should
// exist for the table and then specified row number must be within
// the maximum row count in the table
if (table != null && rowNumber < table.RowCount)
{
return(true);
}
}
return(false);
} // ItemExists
/// <summary>
/// Retrieve the list of tables from the database.
/// </summary>
/// <returns>
/// Collection of DatabaseTableInfo objects, each object representing
/// information about one database table
/// </returns>
internal 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
