dataflow

Go practice project to show how data flows between different layers

Currently in the dataflow.go file, a sqlite database is connected, a table is created, and some data is inserted into the table.

Tasks:

1. Directory Structure

Create your own directory with your user name and copy the dataflow.go to your own directory

2. Error handling

Currently, all DB operations are executed without error handling. Find out which function call will return error and add error handling (eg. print out the error and exit).

3. Organize the intial data

Create a structure "People" to hold the intial data and and use the structure member in the statement.Exec() call.

4. For loop

Put the structured People data into a slice of "Peoples", and use for loop to execute statement.Exec() call.

5. Package

Move the People structure into another go file as a new package, and import People from that package.

6. Query DB

Query from DB the inserted data and print out

7. Use "sqlx"

Replace the database/sql with package github.com/jmoiron/sqlx

8. Query DB to structure

use sqlx db.Select to query DB into the Peoples slice

9. Print with JSON format

Print out the Peoples slice to a json array in the standard output (using "encoding/json") package

10. JSON tags

Add json tags to the People structure, that when marshal the People structure,

• id is omitted
• all keys are in lower case: eg: firstname, instead of Firstname

11. A new structure

Create a new structure PPeople, which includes all the fields of People, and and a new field "Name"

12. Add an interface

Add interface "Present()" to the PPeople structure, which will combile the "Firstname" and "Lastname" to the "Name" field, and then print the whole structure to JSON

13. HTTP Interface

Using "net/http" to run an http server in dataflow.go, which can respond "pong" when getting http://localhost:8080/ping request

14. JSON response

Implement handler for "/peoples" request, and return the PPeople slice in JSON array.

15. Unit test

Implement unit tests for the code written and show the code coverage.