His father Phil said “You always made us laugh, always bringing tears of happiness to our eyes.”
Andrew's father added: “You would always put yourself forward to look after the people around you, and would always see the good in others."
A minute's silence was held by Thames Valley Police, and forces all over the UK, against a backdrop of flowers.
Thames Valley's chief constable, John Campbell, said PC Harper was a "dearly loved and respect colleague, friend and proud police officer".
"This Police Family to which he belonged will not forget him," added the force's chaplain.
Andrew's mum Debbie, said: “We are devastated and bereft but as Andrew always lived with dignity, honour and calmness, we intend to grieve in this way. “
“A big part of me has gone with you, I cannot imagine our lives going forward but we will do so with Andrew in our hearts.”
Andrew’s brother Sean, said: “We all love you so much, I promise you will never be forgotten, and I promise that I will do my best to try to make you as proud of me as I am of you.”
His sister Aimee, said: “It takes my breath away every time the realisation sets in that I never get to see you again. But we were so, so lucky to all be together for the wedding which was perfect, you always brought us together.
All the tributes from Andrew's family can be seen here.
20-year-old Jed Foster from Pingewood near Reading has been charged with PC Harper's murder and is in custody following a court appearance earlier this week.
His lawyer said he denies "any involvement in the horrific murder"
PC Harper was based at Abingdon station in Oxfordshire and had only been married for four weeks.