function Read(var Buffer; Count: Integer): Integer

Read transfers up to Count bytes from the BLOB or CLOB column into Buffer, starting in the current position, and then advances the current position by the number of bytes actually transferred. Read returns the number of bytes actually transferred (which may be less than the number requested in Count). Buffer must have at least Count bytes allocated to hold the data that was read from the column.

All the other reading methods of a TEWBBlobStream object (ReadBuffer, ReadComponent) call Read to do their actual reading.