public bool IsRecordSatisfyingCondition(String tableName1, String tableName2,
Record record1, Record record2,
String col1Name, String col2Name,
String op)
{
CheckIfDatabaseSelected();
TableManager tableManager1 = new TableManager(DbManager.db.Name, tableName1);
TableManager tableManager2 = new TableManager(DbManager.db.Name, tableName2);
Column col1 = tableManager1.table.GetColumnByName(col1Name);
Column col2 = tableManager2.table.GetColumnByName(col2Name);
int col1Index = tableManager1.table.GetColumnIndex(col1);
int col2Index = tableManager2.table.GetColumnIndex(col2);
if (col1Index == -1 || col2Index == -1)
{
throw new Exception("No such column exists");
}
Condition.ConditionType conditionType;
if (op == "=")
{
conditionType = Condition.ConditionType.Equal;
}
else if (op == "<")
{
conditionType = Condition.ConditionType.Less;
}
else if (op == ">")
{
conditionType = Condition.ConditionType.Greater;
}
else if (op == "<=")
{
conditionType = Condition.ConditionType.LessEqual;
}
else if (op == ">=")
{
conditionType = Condition.ConditionType.GreaterEqual;
}
else
{
throw new Exception("Operation " + op + " not supported");
}
if (col1.Type != col2.Type)
{
throw new Exception("Both columns do not have same data type");
}
if (col1.Type == Column.DataType.Int)
{
int valueInt;
if (int.TryParse(record2.Fields[col2Index], out valueInt))
{
Condition cond = new Condition(col1, conditionType, record2.Fields[col2Index]);
return(cond.CompareIntegers(int.Parse(record1.Fields[col1Index])));
}
}
else if (col1.Type == Column.DataType.Double)
{
double valueDouble;
if (double.TryParse(record2.Fields[col2Index], out valueDouble))
{
Condition cond = new Condition(col1, conditionType, record2.Fields[col2Index]);
return(cond.CompareDoubles(double.Parse(record1.Fields[col1Index])));
}
}
else if (col1.Type == Column.DataType.Char)
{
if (conditionType != Condition.ConditionType.Equal)
{
throw new Exception("These type of columns only support equality conditions");
}
if (record2.Fields[col2Index] != null)
{
Condition cond = new Condition(col1, conditionType, record2.Fields[col2Index]);
return(cond.CompareStrings(record1.Fields[col1Index]));
}
}
else
{
throw new Exception("Condition value is not valid");
}
return(false);
}
/**
* Makes condition out from the given parameters
*/
public Condition GetCondition(String tableName, String colName, String op, String value)
{
CheckIfDatabaseSelected();
TableManager tableManager = new TableManager(DbManager.db.Name, tableName);
Column col = tableManager.table.GetColumnByName(colName);
if (col == null)
{
throw new Exception("No such column exists");
}
Condition.ConditionType conditionType;
if (op == "=")
{
conditionType = Condition.ConditionType.Equal;
}
else if (op == "<")
{
conditionType = Condition.ConditionType.Less;
}
else if (op == ">")
{
conditionType = Condition.ConditionType.Greater;
}
else if (op == "<=")
{
conditionType = Condition.ConditionType.LessEqual;
}
else if (op == ">=")
{
conditionType = Condition.ConditionType.GreaterEqual;
}
else
{
throw new Exception("Operation " + op + " not supported");
}
if (col.Type == Column.DataType.Int)
{
int valueInt;
if (int.TryParse(value, out valueInt))
{
return(new Condition(col, conditionType, value));
}
}
else if (col.Type == Column.DataType.Double)
{
double valueDouble;
if (double.TryParse(value, out valueDouble))
{
return(new Condition(col, conditionType, value));
}
}
else if (col.Type == Column.DataType.Char)
{
if (conditionType != Condition.ConditionType.Equal)
{
throw new Exception("These type of columns only support equality conditions");
}
if (value != null)
{
return(new Condition(col, conditionType, value));
}
}
else
{
throw new Exception("Condition value is not valid");
}
return(null);
}