bobbae/dfstore

dfstore

This is an experimental package to implement a database agnostic API that supports various backend databases such as redis, mongodb, PostgreSQL and other SQL databases using the abstraction based on dataframe grids often used in data science projects that depend on python pandas or scala RDD or similar. Use of dataframe in Go language implementation of dfstore depends on gota at

https://github.com/go-gota/gota

https://pkg.go.dev/github.com/go-gota/gota/dataframe#pkg-examples

Example usage

dfstore_test.go

1. Contains test code for postgresql/default usage
2. test code for redis/memory use case
3. test code for document/mongodb use case

dataframe

dataRows = [][]string{
		{"title", "artist", "price"},
		{"Blue Train", "John Coltrane", "56.99"},
		{"Giant Steps", "John Coltrane", "63.99"},
		{"Jeru", "Gerry Mulligan", "17.99"},
		{"Sarah Vaughan", "Sarah Vaughan", "34.98"},
	}

Open databases

	dfs, err := dfstore.New(context.TODO(), dbtype)
	if err != nil {
		t.Errorf("cannot get new dfstore, %v",err)
		return
	}
	defer dfs.Close()

write databases

	err = dfs.WriteRecords(dataRows)
	if err != nil {
		t.Errorf("cannot write, %v", err)
	}

read databases

	filters := []dataframe.F{
		dataframe.F{Colname: "artist", Comparator: series.Eq, Comparando: "John Coltrane"},
		dataframe.F{Colname: "price", Comparator: series.Greater, Comparando: "60"},
	}
	res, err := dfs.ReadRecords(filters, 20)

Testing

Running a test PostgreSQL server

run postgresql server in a docker

docker run --rm --name postgresql -e POSTGRES_PASSWORD=password -p 5432:5432  -e POSTGRES_USER=pguser -e POSTGRES_DB=testdb postgres

run postgres cli in a docker

docker exec -it postgresql psql -h localhost -p 5432 -U pguser -W -d postgres

run the following in psql cli to create schema table

# CREATE DATABASE dfstore1;
# \c dfstore1;
# CREATE TABLE IF NOT EXISTS schema ( tablename VARCHAR(128) PRIMARY KEY, columns VARCHAR(255) NOT NULL );
# \l

running a test redis server

docker run --name redis --rm -p 6379:6379 -d redis

Run redis-cli to require password login

$ redis-cli -a password
# config set requirepass password

Running a test mongodb server

docker run -d --rm --name mongo -it -p 27017:27017 -e MONGO_INITDB_ROOT_USERNAME=root -e MONGO_INITDB_ROOT_PASSWORD=rootpass  mongo

Install mongosh

https://www.mongodb.com/docs/mongodb-shell/install/

Run mongosh

$ mongosh mongodb://root:rootpass@localhost:27017

test> db.dropDatabase('test')


test> use dfstore1
switched to db dfstore1

dfstore1> db.createCollection('table1')

dfstore1> db.getCollectionNames()

dfstore1>  db.createUser( { user: 'root',pwd: 'rootpass', roles: [ { role: "readWrite", db: "dfstore1"} ] } )

dfstore1> db.getUsers()

dfstore1> db.getCollection('table1').find().forEach(printjson)
{
  _id: ObjectId("000000000000000000000000"),
  artist: 'John Coltrane',
  price: 58.99,
  title: 'Blue Train'
}
{ _id: 1, title: 'Blue Train', artist: 'John Coltrane', price: 56.99 }
{ _id: 2, title: 'Giant Steps', artist: 'John Coltrane', price: 63.99 }
{ _id: 3, title: 'Jeru', artist: 'Gerry Mulligan', price: 17.99 }
{
  _id: 4,
  title: 'Sarah Vaughan',
  artist: 'Sarah Vaughan',
  price: 34.98
}

dfstore1>

go test

go test

go test a specific one

go test -run Memory
go test -run Doc 
go test -run Default