how to conditionally match in excel - excel

Question

I've got two data sets: Data-A and Data-B.
Data-A
A B C D Start_Date End_Date
N C P 1 23-05-2015 27-05-2015
N C K 1 30-05-2015 07-06-2015
N C Ke 1 09-06-2015 28-06-2015
N C Ch 1 14-07-2015 25-07-2015
N C Th 1 29-06-2015 13-07-2015
N C Po 2 23-05-2015 27-05-2015
N C Kan 2 30-05-2015 08-06-2015
Data-B
X D Date A B C
444 1 09-07-2015
455 1 20-07-2015
1542 1 28-06-2015
2321 1 21-07-2015
2744 1 01-07-2015
7455 2 25-05-2015
12454 2 02-06-2015
18568 2 24-05-2015
28329 2 03-06-2015
28661 2 31-05-2015
Values is data-Bare missing and I need to fill them using conditional index matching/vlookup such that column D(Data-B) is matched along with Date(Data-B) such that Start Date<= Date <=End Date.
Desired Output:
X D Date A B C
444 1 09-07-2015 N C Th
455 1 20-07-2015 N C Ch
1542 1 28-06-2015 N C Ke
2321 1 21-07-2015 N C Ch
2744 1 01-07-2015 N C Th
7455 2 25-05-2015 N C Po
12454 2 02-06-2015 N C Kan
18568 2 24-05-2015 N C Po
28329 2 03-06-2015 N C Kan
28661 2 31-05-2015 N C Kan

Answer 1

Proof of Concept
In order to achieve the above I used the AGGREGATE function. It is a normal formula that performs array like calculations. The following formula will return the results from the first row that matches your criteria.
=INDEX(A$2:A$8,AGGREGATE(15,6,ROW($D$2:$D$8)/(($J2=$D$2:$D$8)*($E$2:$E$8<=$K2)*($K2<=$F$2:$F$8)),1)-1)
This assumed your table Data-A Started in A1 and included 1 row as a header row. The formula can be place in the first cell under A in Data-B and copied down and to the right as needed.
UPDATE Formula explained
The aggregate function performs array calculations within its brackets for certain sub function. There are about 19 different subfunctions. Subfunction 14 and 15 are both array calculations. This is a nice feature since it does array like calculations while being a regular formula.
Since I wanted the first row that met your criteria, I opted to use the small function or subfunction 15 for the first argument. Basically I am telling the aggregate function to generate a list and sort it in ascending order.
The second argument has a value of 6 which tell the aggregate to ignore any results from the array that generate errors. This will come in very handy if we can make results we do not want turn in to errors.
Now we are getting into the array portion of the formula. You can take this next part of the equation and highlight the appropriate rows in a neighbouring column and enter it as a CONTROL+SHIFT+ENTER (CSE) formula. As long as you do this in the top cell the array formula will propagate to the remainder of the selected cells and show you the results of the array. Also check the formula bar to see if { } appeared around your formula. You cannot add the { } manually.
{=ROW($D$2:$D$8)/(($J2=$D$2:$D$8)*($E$2:$E$8<=$K2)*($K2<=$F$2:$F$8))}
What this will do is determine the current row and then will divide it by the results of our conditions. You can also try each of the following conditions in a separate column as CSE formulas in the same manner described above to see their results.
($J2=$D$2:$D$8)
($E$2:$E$8<=$K2)
($K2<=$F$2:$F$8)
These on their own will provide you with either TRUE or FALSE as it checks each row. Now the interesting thing is, and this applies to excel formulas, when you perform a math operation on a Boolean, it will treat 0 as false and anything other number as TRUE. It will actually convert TRUE to 1. You will also note that each of the logic checks was separated by *. In this case * is acting like an AND operator as only when all results are true will you get an answer of 1. (+ will act like an OR operator)
Now if you remember from earlier 6 said to ignore all errors. So any row that does not meet our logic check will result in a division by 0 since not all logic checks results in TRUE or 1. All the checks that wound up false wind up getting ignored. So now after doing that, a list of only row numbers that met our criteria is left inside the aggregates array.
After the logic check there is a ,1 for the next argument. In this case we are telling the aggregate to return the 1st number in the list which is the first row number that met our criteria. If we wanted the third number, this would be ,3 instead.
So aggregate is returning the first row number of the results we want. When this is paired with an INDEX function, when can use the result to tell us what row of the INDEX function to look in. In this case we said we wanted to look in the index A$2:A$8. The aggregate function is telling us how many rows to go down in the index. If the index had start in row 1 we would not have to do anything. But since there is a header row, we need to adjust the results from the aggregate function by subtracting 1 for the head row (in reality you need to subtract the row number above the start of your data). This is why you see the -1 after the aggregate function.
Now if you pay attention to the lock on the range you will notice I did not lock the A in A$2:A$8. I did this so that I could copy the formula to the right and the column A address would update as I did. This only works because you were keeping the columns in the same order. If the order has changed I would have changed the index from a 1D array to a 2D array and used a MATCH function to line up the column headers.