hqi

hexa query interface

Introduction

Work In Progress,
hqi is meant to interface a flat table query into a common solution and also to easly mock the interface for testing units

Usage

to create query interface we use q := hqi.NewQuery( driver ) Using slicedrv Lets define a struct:

type Model struct {
	Field1 string,
	Field2 int
}

Next we instantiate our slice:

collection := []Model{}

Now we get a query interface using slice driver passing our collection to driver:

q := hqi.NewQuery(&slicedrv.Driver{&collection})

And we can start:

q.Insert(Model{"f1","f2"},Model{"f1_1","f2_2"})   // Inserts the two elements into slice

var result []Model{}
q.Find(Model{"f1","f2"}).List(&result)
q.Find(`{"Field1":"f1"}`,Model{"f1_1","f2_2"}).List(&result)   // Find where Field1 is f1 OR field1 "f1_1" AND field2 "f2_2"

slice example

TODO

• Create driver capabilitie struct so if we are registering a subDocument driver will identify if it can process
• Finder features with operators >= <= < > !=
• Update operation
• Matcher with Greater,Smaller checks, Zero fields
• Create a cursor to fetch parcels of data

DONE

• Schemer (information to pass to driver when user wants a scheme) (staging)
• Insert operation (staging)
• Delete (staging)

Operations (planning)

oper	function	equivalence
NOT	Inverse match	!
GT	Greater Than	>
GTE	Greater equal or equal	>=
LT	Less than	<
LTE	Less than or equal	<

Matcher executor

• Match
• Sort
• Range
• Retrieve, Count,Delete,Update (CRUD here)

Stage based query

On stage based means, that if we perform a query. means we should have only Find option/Match
After find we can have SORT, LIMIT,RESULT
after SORT: LIMIT,RESULT
after RANGE: RESULT

• Stage1 return Find/Schema/Insert (Match)
• Stage2 sort, range, results
• Stage3 All/Delete/Count executors

QuerySampler

rules for Find, if we have a model:

type Person struct {
	Name string
	Age int
}

we could create a "cloned" Sampler as:

type PersonSampler struct {
	Name interface{}
	Age interface{}
}

q.FindS(PersonSampler{Age:0}).  // Usually 0 is nothing and won't match
  List(&res)
// Or also:
q.FindS(PersonSampler{Age:hqi.Greater(10)}).
  List(&res)

---

• DRIVER

Changes:

• 19-04-2017: Update implemented in mgo and slice