Be sure that the values following equal signs are wrapped in single quotes.

Question about the task

Build a WHERE query

Java Multithreading, Level 2, Lesson 9

Resolved

This is what validator suggests to check. But as i can see they are present. Any idea guys?

Build part of a WHERE query using StringBuilder.
If a parameter is null, then it shouldn't be included in the query.

Example:

{name=Johnson, country=United States, city=Los Angeles, age=null}

Result:

name = 'Johnson' and country = 'United States' and city = 'Los Angeles'

Requirements:

The getQuery method must have one Map parameter.
The getQuery method must return a String.
The getQuery method must be static.
The getQuery method must return a string built according to the rules specified in the task conditions.

package com.codegym.task.task22.task2208; import java.util.Map; import java.util.HashMap; import java.util.Formatter; /* Build a WHERE query */ public class Solution { public static void main(String[] args) { Map<String, String> map = new HashMap<>(); map.put("name", "Johnson"); map.put("country", "United States"); map.put("citY", "Los Angeles"); map.put("age", null); System.out.println(getQuery(map)); } public static String getQuery(Map<String, String> params) { String[] arr = {"name", "country", "city", "age"}; StringBuilder sb = new StringBuilder(); Formatter fm = new Formatter(sb); for (int i = 0; i < arr.length; i++) { for(Map.Entry<String, String> me : params.entrySet()){ if (me.getKey().equalsIgnoreCase(arr[i])&& me.getValue()!=null) fm.format("%s = '%s' and ",arr[i], me.getValue()); } } sb.delete(sb.length()-5, sb.length()); return sb.toString(); } }

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Jay

Level 0

13 November 2019, 11:58

@Evghenii Seremet, Two of the below areas why the task condition didn't satisfy : 1. You are adding the " and " string in the format method with every string and that in turn is causing your final string builder result with an extra " and " appended at end of it. 2. The delete operation at the last is completely incorrect as it will randomly delete whatever string it finds at the last. Please check the below code which may help you to pass the condition in your task. It checks the map size and keeps on appending the "and " keyword to the where clause and terminates the process as soon as it finds that map size is already reached.

StringBuilder sb = new StringBuilder();
	        Formatter fm = new Formatter(sb);
	        int i = 1;
	         for(Map.Entry<String, String> me : map.entrySet()){
	        	 if(!(me.getValue() == null)) {
	        		fm.format("%s = '%s'",me.getKey(), me.getValue());
	        		if(i != map.size()-1) {
	        			sb.append(" and ");
	        			i++;
	        		}

	        	 }
	         }