As an initial step of building a Utility to get meaningful information out of our Raw data - **as a first step you should be able to parse (decipher) our question. In our computing terms, we call this a query.**Our system should be able to interpret this and break it into several parts - so that necessary actions can be triggered to fetch the required information in the proper format.
Please note that the End User interacting with this utility will give out SQL like instructions and would expect the system to respond with necessary information. The system perceives this as a String of characters and we should manipulate and break this string into appropriate Data Structures. For Instance,
Query: SELECT winner, Count( winner ) FROM ipl.csv WHERE win_by_runs > 100 GROUP BY winner ORDER BY winner;
Sample Data:
| winner | Count(winner) |
|---|---|
| Kings XI Punjab | 1 |
| Kolkata Knight Riders | 1 |
| Rajasthan Royals | 1 |
| Royal Challengers Bangalore | 3 |
Query: SELECT city, winner FROM ipl.csv WHERE winner='Chennai Super Kings' AND city ='Abu Dhabi' AND season=2014;
Sample Data:
| city | winner |
|---|---|
| Abu Dhabi | Chennai Super Kings |
Few terms need to understand before starting the project.
1.select -> get the required information
2.'*' -> select all the fields
3.where -> filter result
4.order by -> sort the result based on particular field
5.group by -> get the records together based on the particular field.
6.aggregate -> There are 5 aggregates,they are "sum,count,min,max,avg".
7.Example query string : select season,winner,player_match from ipl.csv where season > 2014 and city = 'Bangalore';
a.fetching season, winner, player_match
b.from the file ipl.csv (csv -> Comma Separated Value)
c.where - filter the results. Get the details of the matches played in Bangalore after season 2014
d.ipl.csv - a name of the file from which we need to fetch the information/records
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Write a program to read the query string as input and split them into words. Print the output on the console as given below:
Input String : select * from ipl.csv where season > 2014 and city = 'Bangalore'
Output String: select * from ipl.csv
where
season > 2014 and city = 'bangalore' -
Further, enhance your program to now extract certain parts of the same query:
i. Get only file name from the query string.
Input String : select * from ipl.csv where season > 2014 and city = 'Bangalore' Output String : ipl.csv -
Get only base part(before
whereword) of the query from the given query string.Input String : select * from ipl.csv where season > 2014 and city = 'Bangalore' Output String : select * from ipl.csv
1)Extract the selected fields/information from the given query.
Input String : select city,winner,player_match from ipl.csv where season > 2014
and city = 'Bangalore'
Output String : city
winner
player_match
2)Get only filter part(after where word before'group by or order by' if they exist in the query) of the query from the given query string.
Input String : select * from ipl.csv where season > 2014 and city = 'Bangalore'
Output String : season > 2014 and city ='bangalore'
Input String : select city from ipl.csv where season > 2014 or city = 'Bangalore'
order by city
Output String : season > 2014 or city = 'bangalore
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As there will be multiple conditions, separate each condition and display in the different line.
Input String : select * from ipl.csv where season > 2014 and city = 'Bangalore' Output String : season > 2014 city ='bangalore'
##Our STEP III involves two tasks, given below:
1)Extract the logical operators in sequence from the given query string. Note: Logical operators are "and, or, not"
Input String : select season,winner,player_match from ipl.csv where season > 2014 and city ='Bangalore' or date > '31-12-2014'
Output String :
and
or
2)Extract the order by field from the given string. Note : The user may need the information in sorted order of a particular field.
Input String : select * from ipl.csv where season > 2016 and city= 'Bangalore' order by win_by_runs
Output String : win_by_runs
##Our STEP IV involves two tasks, given below:
1)Extract the group by field from the given string. Note : The user may need the related information grouped together. For Example they may require to see the information department wise.
Input String : select team1, city from ipl.csv where season > 2016 and city='Bangalore' group by team1
Output String : team1
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User may require the information like who is getting maximum salary or minimum age etc.. these are called aggregate functions (minimum, maximum, count, average, sum)
Input String : select avg(win_by_wickets),min(win_by_runs) from ipl.csv Output String : avg(win_by_wickets) min(win_by_runs)
Note: Other parts like where clause, order by, group by may be present in the query.
Displaying various components/parts of the query like selected fields, conditional parts, aggregate fields, groupBy field, OrderBy field
The folders and files you see in this repositories, is how it is expected to be in projects, which are submitted for automated evaluation by Hobbes
Project
|
├── com.stackroute.datamunger // all your java file will be stored in this package
| └── DataMunger.java // This is the main file, all your logic is written in this file only
├── com.stackroute.datamunger.test // all your test cases will be stored in this package
| └── DataMungerTest.java // all your test cases are written using JUnit, these test cases can be run by selecting Run As -> JUnit Test
| └──DataMungerTestTask1.java
| └──DataMungerTestTask2.java
| └── DataMungerTestTask3.java
| └── DataMungerTestTask4.java
|
├── .classpath // This file is generated automatically while creating the project in eclipse
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├── .hobbes // Hobbes specific config options, such as type of evaluation schema, type of tech stack etc., Have saved default values for convenience
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├── .project // This is automatically generated by eclipse, if this file is removed your eclipse will not recognize this as your eclipse project.
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├── pom.xml // This is a default file generated by maven, if this file is removed your project will not get recognized in hobbes.
|
└── PROBLEM.md // This files describes the problem of the assignment/project, you can provide as much as information and clarification you want about the project in this file
PS: All lint rule files are by default copied during the evaluation process, however if need to be customizing, you should copy from this repo and modify in your project repo
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Clone the base boilerplate in the folder assignment-solution-step1 of your local machine
git clone https://gitlab.stackroute.in/Boeing-Immersive/wave1/DataMungerStep1_Boilerplate -
Navigate to assignment-solution-step1 folder
cd assignment-solution-step1 -
Remove its remote or original reference
git remote rm origin -
Create a new repo in gitlab named
assignment-solution-step1as private repo -
Add your new repository reference as remote
git remote add origin https://gitlab.stackroute.in/{{yourusername}}/assignment-solution-step1.gitNote: {{yourusername}} should be replaced by your username from gitlab
-
Check the status of your repo
git status -
Use the following command to update the index using the current content found in the working tree, to prepare the content staged for the next commit.
git add . -
Commit and Push the project to git
git commit -a -m "Initial commit | or place your comments according to your need"git push -u origin master -
Check on the git repo online, if the files have been pushed
- We expect you to write the assignment on your own by following the guidelines, learning plan, and the practice exercises
- The code must not be plagiarized, the mentors will randomly pick the submissions and may ask you to explain the solution
- The code must be properly indented, code structure maintained as per the boilerplate and properly commented
- Follow the problem statement shared with you
*** Release 0.1.0 ***
- Right-click on the Assignment select Run As -> Java Application to run your Assignment.
- Right-click on the Assignment select Run As -> JUnit Test to run your Assignment.