Query Builder Generator.
qbg can generate type safe wrapper for appengine datastore.
If you use string literal for building query, You shoots your foot when you do typo. qbg generate appengine datastore wrapper code. It is type safe. Your mistake will be found by go compiler.
type User struct {
Name string
}
user := &User {
"go-chan",
}
builder := NewUserQueryBuilder()
builder.Name.Equal("go-chan")
cnt, err := builder.Query().Count(c)
from:
type Sample struct {
Foo string
}
to:
// generated!
// for Sample
type SampleQueryBuilder struct {
q *datastore.Query
plugin qbgutils.Plugin
Foo *SampleQueryProperty
}
type SampleQueryProperty struct {
bldr *SampleQueryBuilder
name string
}
usage:
src := &Sample{"Foo!"}
builder := NewSampleQueryBuilder() // generated!
builder.Foo.GreaterThanOrEqual("Foo")
cnt, err := builder.Query().Count(c)
$ ls -la .
total 8
drwxr-xr-x@ 3 vvakame staff 102 10 13 17:39 .
drwxr-xr-x@ 7 vvakame staff 238 8 14 18:26 ..
-rw-r--r--@ 1 vvakame staff 178 8 14 18:26 model.go
$ cat model.go
//go:generate qbg -output model_query.go .
package c
import "time"
// +qbg
type Sample struct {
ID int64 `goon:"id"`
CreatedAt time.Time `datastore:",noindex"`
}
$ go generate
$ ls -la .
total 16
drwxr-xr-x@ 4 vvakame staff 136 10 13 17:40 .
drwxr-xr-x@ 7 vvakame staff 238 8 14 18:26 ..
-rw-r--r--@ 1 vvakame staff 178 8 14 18:26 model.go
-rw-r--r-- 1 vvakame staff 3709 10 13 17:40 model_query.go
Please use with goon.
$ go get -u github.com/favclip/qbg/cmd/qbg
$ qbg
Usage of qbg:
qbg [flags] [directory]
qbg [flags] files... # Must be a single package
Flags:
-output="": output file name; default srcdir/<type>_query.go
-type="": comma-separated list of type names; must be set
Model with type specific option.
$ cat misc/fixture/a/model.go
package a
// test for basic struct definition
type Sample struct {
Foo string
}
$ qbg -type Sample -output misc/fixture/a/model_query.go misc/fixture/a
Model with tagged comment.
$ cat misc/fixture/c/model.go
//go:generate qbg -output model_query.go .
package c
import "time"
// +qbg
type Sample struct {
ID int64 `goon:"id"`
CreatedAt time.Time `datastore:",noindex"`
}
$ qbg -output misc/fixture/d/model_query.go misc/fixture/d