public bool Filter(Row r)
{
if ((string)r[Field] != Value)
{
return false;
}
return true;
}
public ITable Execute(Database db)
{
ITable t = db.Tables[Query.TableName];
Row nr = new Row(t);
foreach (Set s in Query.Sets)
{
nr[s.Field] = s.Value;
}
t.AddRow(nr);
return null;
}
// <summary>Retrieve the next row. Uses a seek,
// assuming the underlying framework will be sensible about it
// (we should usually already be in position)</summary>
public Row NextRow()
{
_fs.Seek(this.Header.Size + (this._currentRow * this.Header.RowLength),0);
Row r = new Row(this);
r.BinRead(this.Columns, this._br);
this._currentRow++;
return r;
}
// <summary>
// Writes a row to disk
// </summary>
public void AddRow(Row r)
{
if (r.Table != this)
{
throw new InvalidOperationException("Can't add row - doesn't belong to this table");
}
_fs.Seek(_fs.Length, 0);
BinaryWriter bw = new BinaryWriter(_fs);
r.BinWrite(bw);
this.Header.RowCount += 1;
_fs.Seek(0, 0);
this.Header.BinWrite(bw);
bw.Flush();
}
public override bool NextResult()
{
if (!this.UnderlyingTable.HasRows)
{
return false;
}
this.CurrentRow = this.UnderlyingTable.NextRow();
return true;
}
// <summary>Generally used for creating new rows out of
// old ones, particularly when joining rows together</summary>
public void CopyData(Row old, List<Column> newColumns)
{
object[] oldd = this._data;
this._data = new object[this.Table.Columns.Count];
oldd.CopyTo(this._data, 0);
foreach (Column c in newColumns)
{
// Check if the column exists on this table,
// if it does copy the value in
if (this.Table.Columns.Find(o => o.Name == c.Name) != null &&
old.Table.Columns.Find(o => o.Name == c.Name) != null)
{
// find the matching old column
this[c.Name] = old[c.Name];
}
}
}
