loopback 4 where like code example
Example 1: loopback where between
filter[where][price][between][0]=0&filter[where][price][between][1]=7
...
Shirts.find({where: {size: {between: [0,7]}}}, function (err, posts) { ... } )
Example 2: loopback model count
PersistedModel.count([where], callback)