You can go to a hardware shop...take your hose fitting with you..and ask for a "sambungan drat luar". (thats how it sounds anyway). Its a "Connector with an outside thread"
hopefully is brass, then you can buy a brass tap (dissasemble it so you dont melt the washers inside), take it to a "benkel las" (welding shop), and get them to braze it on.
ive been looking too, but never found anything suitable.
In the end i just bought a good quality hose clamp with a wide band (Klamp selang) and clamped it on.
If you have normal house pressure (32psi in the west...usually about 20 psi here though) it should hold.
if youve got a garden fitting on the end of your hose that you can turn off at the nozzle....make sure you turn it off at the tap, not at the nozzle...and it should never come off...even if the clamps not great. (im sure you already know this)