public static WhereResult Where(ITabularReader reader, string columnIdentifier, string operatorString, string valueString, ITabularWriter writer)
{
int colIndex = reader.ColumnIndex(columnIdentifier);
WhereResult result = new WhereResult()
{
ColumnIndex = colIndex, ColumnName = reader.Columns[colIndex], Op = OperatorExtensions.Parse(operatorString), Value = ConvertToBestType(valueString)
};
Type t = result.Value.GetType();
if (t == typeof(bool))
{
MatchBoolCompare(reader, writer, result);
}
else if (t == typeof(int))
{
MatchIntCompare(reader, writer, result);
}
else if (t == typeof(DateTime))
{
MatchDateTimeCompare(reader, writer, result);
}
else if (result.Op == Operator.Contains)
{
MatchContains(reader, writer, result);
}
else if (result.Op == Operator.StartsWith)
{
MatchStartsWith(reader, writer, result);
}
else
{
MatchStringCompare(reader, writer, result);
}
result.RowCount = reader.RowCountRead;
return(result);
}
private static void MatchBoolCompare(ITabularReader reader, ITabularWriter writer, WhereResult result)
{
bool value = (bool)result.Value;
while (reader.NextRow())
{
// Ensure the row has enough columns
if (reader.CurrentRowColumns <= result.ColumnIndex)
{
continue;
}
// Ensure the value converts
bool columnValue;
if (!reader.Current(result.ColumnIndex).ToString8().TryToBoolean(out columnValue))
{
continue;
}
int compareResult = columnValue.CompareTo(value);
if (!result.Op.Matches(compareResult))
{
continue;
}
result.MatchCount++;
// If this is the matching row, write it
EchoRow(reader, writer);
}
}
private static void MatchContains(ITabularReader reader, ITabularWriter writer, WhereResult result)
{
string valueString = (string)result.Value;
String8 value = String8.Convert(valueString, new byte[String8.GetLength(valueString)]);
while (reader.NextRow())
{
// Ensure the row has enough columns
if (reader.CurrentRowColumns <= result.ColumnIndex)
{
continue;
}
// Match the value
if (reader.Current(result.ColumnIndex).ToString8().IndexOf(value) == -1)
{
continue;
}
result.MatchCount++;
// If this is the matching row, write it
EchoRow(reader, writer);
}
}