/**
* After checking for error if any, inserts the record into
* the table and index file
*/
public void InsertRecordToTable(String tableName, Record record)
{
CheckIfDatabaseSelected();
TableManager tableManager = new TableManager(DbManager.db.Name, tableName);
tableManager.CheckRecord(record); //checks for any error in the record
if (tableManager.table.PrimaryKey != null)
{
Column pKey = tableManager.table.PrimaryKey;
int pKeyIndex = tableManager.table.GetColumnIndex(pKey);
String pKeyVal = record.Fields[pKeyIndex];
//checking if record null
if (pKeyVal == null)
{
throw new Exception("Primary Key Value can't be null");
}
//check for duplicacy
Dictionary <int, Record> records = SelectRecordsFromTable(tableName,
new Condition(pKey, Condition.ConditionType.Equal, pKeyVal));
if (records.Count > 0)
{
throw new Exception("Primary Key Value already exists");
}
}
int address = tableManager.InsertRecord(record);
tableManager.InsertRecordToIndices(record, address);
}
/**
* @param name="condition" updates records which satisfy the condition
* if null that means update all
*
* @param name="updatedColumns" has those entries set which have been
* changed and rest of the entries are null
*
* Check for error if there in updatedColumns
* If no error combine with old records to get new and updated records
*/
public void UpdateRecordToTable(String tableName, Record updatedColumns, Condition condition)
{
CheckIfDatabaseSelected();
TableManager tableManager = new TableManager(DbManager.db.Name, tableName);
//checking for errors in objects
tableManager.CheckRecord(updatedColumns);
if (!tableManager.table.CheckIfConditionValid(condition))
{
throw new Exception("Condition is not valid");
}
Dictionary <int, Record> oldRecords = SelectRecordsFromTable(tableName, condition);
if (tableManager.table.PrimaryKey != null)
{
Column pKey = tableManager.table.PrimaryKey;
int pKeyIndex = tableManager.table.GetColumnIndex(pKey);
String pKeyVal = updatedColumns.Fields[pKeyIndex];
//checking if more than 1 record will get changed
if (oldRecords.Count > 1 && pKeyVal != null)
{
throw new Exception("More than 1 record satisfies condition");
}
}
Dictionary <int, Record> newRecords = new Dictionary <int, Record>(oldRecords);
for (int i = 0; i < updatedColumns.Fields.Count; i++) //updating new records
{
String value = updatedColumns.Fields[i];
if (value != null)
{
foreach (KeyValuePair <int, Record> pair in newRecords)
{
pair.Value.Fields[i] = value;
}
}
}
tableManager.UpdateRecord(newRecords);
tableManager.UpdateRecordToIndices(oldRecords, newRecords);
}