public DataTable Select(string tablename, List <string> fields, List <string> groupFields, WhereDelegate where)
{
if (groupFields != null && groupFields.Count == 0)
{
groupFields = null;
}
EasyTable table = FindTable(tablename);
EasyBoolColumn rows = null;
if (where != null)
{
rows = where ();
//rows = (EasyBoolColumn)rows.Custom("&", table.RowColumn, EasyBaseColumn.COLLECT);
}
DataTable dt = new DataTable();
//List<EasyBaseColumn> selectedFields = new List<EasyBaseColumn>();
Dictionary <string, EasyBaseColumn> selectedFields = new Dictionary <string, EasyBaseColumn>();
foreach (string field in fields)
{
if (field != "*")
{
EasyBaseColumn column = null;
if (SqlParser.IsId(field))
{
column = table.FindColumn(field);
//selectedFields.Add(column);
selectedFields[field] = column;
dt.Columns.Add(field, column.GetColumnType());
}
else
{
List <string> t = SqlParser.Tokenize(field);
column = (EasyBaseColumn)ExecuteExpression(table, t);
//selectedFields.Add(column);
selectedFields[field] = column;
dt.Columns.Add(field, column.GetColumnType());
}
}
else
{
foreach (var column in table.Columns)
{
//selectedFields.Add(column);
selectedFields[column.Name] = column;
dt.Columns.Add(column.Name, column.GetColumnType());
}
}
}
//if (rows != null)
// {
int k = 0;
int rowCount = 0;
foreach (EasyBaseColumn column in selectedFields.Values)
{
rowCount = column.GetRowCount();
break;
}
Hashtable previousValues = new Hashtable();
for (int i = 0; i < rowCount; i++)
{
if (rows != null && !rows.Values[i])
{
continue;
}
if (table.RowColumn.Values[i] == 0)
{
continue;
}
int j = 0;
bool group = false;
if (groupFields != null)
{
group = true;
foreach (string groupField in groupFields)
{
if (k > 0)
{
object val = selectedFields[groupField].GetValue(i);
if (!selectedFields[groupField].EQ(val, previousValues[groupField]))
{
group = false;
previousValues[groupField] = val;
}
}
else
{
group = false;
previousValues[groupField] = selectedFields[groupField].GetValue(i);
}
}
}
if (group)
{
continue;
}
dt.Rows.Add();
foreach (EasyBaseColumn column in selectedFields.Values)
{
dt.Rows[k][j] = column.GetValue(i);
j++;
}
k++;
}
//}
//else
//{
// int k = 0;
// int rowCount = 0;
// foreach (EasyBaseColumn column in selectedFields.Values)
// {
// rowCount = column.GetRowCount();
// break;
// }
// for (int i = 0; i < rowCount; i++)
// {
// if (table.RowColumn.Values[i] == 0) continue;
// dt.Rows.Add();
// int j = 0;
// foreach (EasyBaseColumn column in selectedFields.Values)
// {
// dt.Rows[k][j] = column.GetValue(i);
// j++;
// }
// k++;
// }
//}
return(dt);
}