// reserve area to store i.e. sector to store blocks containing 5 records
public void ReserveSectorForTable(String dbPath, String databaseName, String sectorName)
{
TableStructure ts = new TableStructure();
String path = dbPath + databaseName + "/" + sectorName;
Directory.CreateDirectory(path);
IFormatter formatter = new BinaryFormatter();
try
{
Stream stream = new FileStream(path + "/" + 0 + ".obj", FileMode.Create, FileAccess.Write);
formatter.Serialize(stream, ts);
stream.Close();
}
catch (IOException i)
{
}
}
public Object DeleteRecord(String tableName, dynamic whereField)
{
String useDB = getDatabaseName();
TableStructure ts = null;
TableController to = new TableController();
String filePath = "";
List <String> whereItemField = new List <String>();
ArrayList whereFieldPosition = null;
List <String> whereItemFieldList = new List <String>();
IFormatter formatter = new BinaryFormatter();
if (whereField != null)
{
whereItemFieldList = OperatorSplit(whereField);
whereItemField.Add(whereItemFieldList[0].Trim());
String[] whereFieldsArray = new String[whereItemField.Count()];
whereFieldsArray = whereItemField.ToArray();
whereFieldPosition = to.FindValuePosition(dbPath, useDB, tableName, whereFieldsArray);
}
ArrayList blocks = to.GetBlock(dbPath, useDB, tableName);
//ArrayList<ArrayList<String>> returnRecords = new ArrayList<ArrayList<String>>();
foreach (int block in blocks)
{
// int newBlock = 0;
filePath = useDB + "/" + tableName + "/" + block + ".obj";
try
{
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
ts = (TableStructure)(formatter.Deserialize(stream));
stream.Close();
}
catch (Exception ex) {
Console.Write(ex.Message.ToString());
}
ArrayList rowsToBeDeleted = new ArrayList();
foreach (ArrayList rows in ts.table)
{
string ind = whereFieldPosition[0].ToString();
string row = rows[int.Parse(ind)].ToString();
string field = whereItemFieldList[1].ToString().TrimEnd(';');
string newWhereField = whereField.ToString().TrimEnd(';');
if (whereField != null)
{
if (Operators(whereField, row, whereItemFieldList[1]))
{
// returnRecords.add(rows);
rowsToBeDeleted.Add(rows);
}
}
}
ts.table.Remove(rowsToBeDeleted);
try
{
if (File.Exists(filePath))
{
File.Delete(filePath);
}
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Write);
formatter.Serialize(stream, ts);
stream.Close();
}
catch (IOException e)
{
Console.Write(e.Message.ToString());
}
// if no where clause is present delete all the file in the sector
}
// add a new file if no where clause is present
if (!whereField != null)
{
try {
ts.table = null;
Stream stream = new FileStream(dbPath + useDB + "/" + tableName + "/" + 0 + ".obj", FileMode.Open, FileAccess.Write);
formatter.Serialize(stream, ts);
stream.Close();
} catch (IOException ex)
{
// TODO Auto-generated catch block
Console.Write(ex.Message.ToString());
}
}
return("Row(s) deleted");
}
public Object UpdateTableValues(String tableName, String setString, dynamic whereField)
{
String useDB = getDatabaseName();
TableStructure ts = null;
TableController tc = new TableController();
List <String> whereItemField = new List <string>();
ArrayList whereFieldPosition = null;
List <String> whereItemFieldList = null;
IFormatter formatter = new BinaryFormatter();
if (whereField != null)
{
whereItemFieldList = OperatorSplit(whereField);
whereItemField.Add(whereItemFieldList[0]);
String[] whereFieldsArray = new String[whereItemField.Count];
whereFieldsArray = whereItemField.ToArray();
whereFieldPosition = tc.FindValuePosition(dbPath, useDB, tableName, whereFieldsArray);
}
ArrayList returnRecords = null;
ArrayList columnToSetPositions = new ArrayList();
String[] setColumnName = setString.Split('=');
columnToSetPositions = tc.FindValuePosition(dbPath, useDB, tableName, setColumnName);
int columnToSetPosition = int.Parse(columnToSetPositions[0].ToString());
String valueToSet = setColumnName[1].Replace("'", "");
foreach (int block in tc.GetBlock(dbPath, useDB, tableName))
{
returnRecords = new ArrayList();
String filePath = dbPath + useDB + "/" + tableName + "/" + block + ".obj";
try
{
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
ts = (TableStructure)formatter.Deserialize(stream);
stream.Close();
}
catch (Exception ex) {
Console.Write(ex.Message.ToString());
}
// ArrayList<String> returnRows = new ArrayList<String>();
foreach (ArrayList rows in ts.table)
{
string ind = whereFieldPosition[0].ToString();
string row = rows[int.Parse(ind)].ToString();
string field = whereItemFieldList[1].ToString().TrimEnd(';');
string newWhereField = whereField.ToString().TrimEnd(';');
if (whereField != null)
{
if (Operators(newWhereField, row, whereItemFieldList[1]))
{
rows.Insert(columnToSetPosition, valueToSet.ToString().TrimEnd(';'));
}
}
else
{
rows.Insert(columnToSetPosition, valueToSet);
}
returnRecords.Add(rows);
}
ts.table = returnRecords;
try
{
if (File.Exists(filePath))
{
File.Delete(filePath);
}
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Write);
formatter.Serialize(stream, ts);
stream.Close();
}
catch (Exception ex)
{
Console.Write(ex.Message.ToString());
}
}
return("Delete action completed");
}
public ArrayList SelectTableValues(String tableName, String fieldsString, dynamic whereField)
{
String useDB = getDatabaseName();
IFormatter formatter = new BinaryFormatter();
TableController to = new TableController();
// IndexStructure ix = null;
TableStructure ts = null;
// TableOperations to = new TableOperations();
List <String> whereItemField = new List <string>();
ArrayList whereFieldPosition = null;
String indexFieldName = "";
List <String> whereItemFieldList = null;
if (!(String.IsNullOrEmpty(whereField)))
{
whereItemFieldList = OperatorSplit(whereField);
whereItemField.Add(whereItemFieldList[0]);
String[] whereFieldsArray = new String[whereItemField.Count()];
whereFieldsArray = whereItemField.ToArray();
whereFieldPosition = to.FindValuePosition(dbPath, useDB, tableName, whereFieldsArray);
}
ArrayList returnRecords = new ArrayList();
ArrayList columnPositions = new ArrayList();
String[] columnNames = fieldsString.Split(',');
columnPositions = to.FindValuePosition(dbPath, useDB, tableName, columnNames);
int blockPointer = 0;
int recordPointer = 0;
ArrayList blocks = new ArrayList();
if ((indexFieldName.Length == 0) && whereField != null)
{
blocks = to.GetBlock(dbPath, useDB, tableName);
}
else
{
blocks.Add(blockPointer);
}
foreach (int block in blocks)
{
String filePath = dbPath + useDB + "/" + tableName + "/" + block + ".obj";
try
{
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
ts = (TableStructure)(formatter.Deserialize(stream));
stream.Close();
}
catch (IOException i)
{
Console.Write(i.Message.ToString());
}
if ((indexFieldName.Length == 0) || (indexFieldName.Equals(null)))
{
ts.table = ts.table;
}
else
{
//ArrayList myRow = new ArrayList();
var myRow = ts.table[recordPointer];
ts.table = null;
ts.table.Add(myRow);
}
foreach (ArrayList row in ts.table)
{
ArrayList returnRows = new ArrayList();
//foreach (int columnPosition in columnPositions)
//{
if (!String.IsNullOrEmpty(whereField))
{
string ind = whereFieldPosition[0].ToString();
string rows = row[int.Parse(ind)].ToString();
string field = whereItemFieldList[1].ToString().TrimEnd(';');
string newWhereField = whereField.ToString().TrimEnd(';');
if (Operators(newWhereField, rows, field))
{
returnRows.Add(row);
returnRecords.Add(returnRows);
}
}
else
{
returnRows.Add(row);
returnRecords.Add(returnRows);
}
//}
//returnRecords.Add(returnRows);
}
}
returnRecords = SetColumnPosition(columnPositions, returnRecords);
return(returnRecords);
}
// Select values from specified table
public String DeleteRecord(string tableName, string whereString)
{
//Check if a database is selected
if (dbPath != null)
{
string filePath = dbPath + "\\" + "mydb" + "\\" + tableName;
TableStructure ts = new TableStructure();
string[] operatorArray = { "<", ">", "=", "!=" };
//Variables to store where conditions
string column = "";
string chosenOperator = "";
string value = "";
//Loop through the operators array and check if the operator in the whereString exists in the array
foreach (string ioperator in operatorArray)
{
if (whereString.Contains(ioperator))
{
chosenOperator = ioperator;
}
}
//Get the column to traverse
column = whereString.Split(new string[] { chosenOperator }, StringSplitOptions.None)[0].Trim();
//Get the value to delete based on
value = whereString.Split(new string[] { chosenOperator }, StringSplitOptions.None)[1].Trim();
try
{
//Loop through all data in the table
foreach (string block in Directory.EnumerateFiles(filePath, "*.obj", SearchOption.TopDirectoryOnly))
{
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream(block, FileMode.Open, FileAccess.Read);
//Deserialize the block
if (stream.Length != 0)
{
if (File.Exists(block))
{
ts = (TableStructure)(formatter.Deserialize(stream));
}
}
stream.Close();
using (StreamReader reader = new StreamReader(block))
{
while (reader.ReadLine() != null)
{
ts.table.Add(reader.ReadLine());
}
}
foreach (ArrayList item in ts.table)
{
var strings = item.Cast <string>().ToArray();
string test = string.Join(",", strings);
Console.WriteLine(test);
}
}
}
catch (IOException e)
{
Console.WriteLine("IOException: {0}", e);
}
}
//No database selected
else
{
Console.WriteLine("Error! No database selected.");
}
return("true");
}
public String InsertIntoTable(String tableName, String valuesString)
{
String returnString = "";
String useDB = getDatabaseName();
TableController to = new TableController();
IFormatter formatter = new BinaryFormatter();
int currentBlockSize = (to.GetBlock(dbPath, useDB, tableName).Count);
int lastBlockID = 0;
if (currentBlockSize < 1)
{
lastBlockID = (to.GetBlock(dbPath, useDB, tableName).Count);
}
else
{
lastBlockID = (to.GetBlock(dbPath, useDB, tableName).Count) - 1;
}
String filePath = dbPath + useDB + "/" + tableName + "/" + lastBlockID + ".obj";
TableStructure ts = new TableStructure();
String[] valuesList = valuesString.Split(',');
ArrayList valuesArray = new ArrayList();
try
{
Stream stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
if (stream.Length != 0)
{
if (File.Exists(filePath))
{
ts = (TableStructure)(formatter.Deserialize(stream));
Console.WriteLine(ts);
//stream.Close();
}
}
stream.Close();
foreach (String value in valuesList)
{
valuesArray.Add(value.Trim().Replace("'", "").Trim());
}
ts.table.Add(valuesArray);
/**
* check if block contains maximum number of elements if it does
* create a data block by incrementing lastDatablock id by one
* otherwise write to the current data block
*/
if ((ts.table.Count - 1) == 5)
{
ts.table.Clear();
ts.table.Add(valuesArray);
int nextBlockID = lastBlockID + 1;
filePath = dbPath + useDB + "/" + tableName + "/" + nextBlockID + ".obj";
}
if (File.Exists(filePath))
{
File.Delete(filePath);
}
stream = new FileStream(filePath, FileMode.Create, FileAccess.Write);
formatter.Serialize(stream, ts);
stream.Close();
returnString = "1 record was inserted";
}
catch (Exception e) {
// TODO Auto-generated catch block
e.Message.ToString();
}
return(returnString);
}