Code Zhandwa

Finally, I get a chance to try out groovy for “real”.

Objective: Create a set of SQL queries, where a certain column holds the value of a country code. So what I needed was something like this:

insert into the-table values('the-country-code', 'some-value', 'and-more');

Looks simple enough. I already have the list of country codes in a file, separated by new-lines. All I have to do is go through the file, reading one line at a time and generate the queries. Since this was a temp job, and I only needed to save the final set of scripts, I really didn’t want to write a Java class (neither did I want to just get-it-done using Textpad). So, I thought of groovy.

I had installed groovy way back - though never quite used it. So, I fired the groovy console up and started typing - all the time missing an IDE and the fact that the console puts Vista back to Basic mode.

This is what I came up with:

import java.io.File
 
new File("C:/1.txt").eachLine{ line ->
    println "insert into the-table values('" + line + "', 'some-value', 'and-more');"
}

I thought this would do the trick. I would just copy paste the output to a file. Well, it kinda stopped after processing some lines (mind you, the actual SQL query that I generated was much longer than this one, so imagine flushing out huge 205 SQL queries to the console).

So, I happily took the next step and decided to write the output to another file.

import java.io.File
 
targetFile = new File("C:/2.txt")
new File("C:/1.txt").eachLine{line ->
    targetFile.write("insert into the-table values('" + line + "', 'some-value', 'and-more');")
}

Okay, this did the trick, but all I got was ONE SQL query. ONE. 1. Okay, so .write just writes to the whole file. I needed the groovy equivalent of an append method. Again, I missed an IDE, but simply enough .append was the answer.

import java.io.File
 
targetFile = new File("C:/2.txt")
new File("C:/1.txt").eachLine{line ->
    targetFile.append("insert into the-table values('" + line + "', 'some-value', 'and-more');")
}

Bingo, we have our queries. But all in one single long line. Let’s decorate it a bit, so that it looks a bit cleaner and slicker.

Added a new line character at the end of the query. :p

import java.io.File
 
targetFile = new File("C:/2.txt")
new File("C:/1.txt").eachLine{line ->
    targetFile.append("insert into the-table values('" + line + "', 'some-value', 'and-more');\n")
}

Cool, isn’t it. I did one more thing so that I don’t keep appending stuff over multiple runs, and this is how my final groovy code looked like.

import java.io.File
 
targetFile = new File("C:/2.txt")
if (targetFile.exists()) targetFile.write("")
new File("C:/1.txt").eachLine{line ->
    targetFile.append("insert into the-table values('" + line + "', 'some-value', 'and-more');\n")
}

Totally zhandwa. Highly groovy.