After breaking down the ZConnection component, let's now study the ZQuery component, property by property. There will be several videos in the series. This is just the first in the series, try to watch them in order.
This video is part of a very important article: https://gladiston.net.br/programacao/lazarus-ide/usando-o-zquery/
Which also makes the Lazarus Survival Guide: https://gladiston.net.br/programacao/lazarus-ide/