How to find similar and equal values in one column and then another column

[fcf]

num_A	num_B	name	birth_date	id
1234	abcd	M Rita Costa Santos	01/01/2000	1
3333	uvwx	M Rita Costa Santos	01/01/2000	1
5678	efgh	Maria Rita C Santos	01/01/2000
9101	ijkl	Rita Costa Santos	01/01/2000	1
1111	mnop	Maria Leonor Santos Silva	02/03/2001
2222	qrst	Leonor Santos Silva	02/03/2001	2
4444	yzab	Leonor Santos Silva	30/08/1999

Imagine I have this table, but in a large scale. I want to find similar and equal values in the name column and if they are similar/equal, go to the column birth_date and see if they are equal. If yes, create the same id for this cases. So i want the final output to be:

num_A	num_B	name	birth_date	id
1234	abcd	M Rita Costa Santos	01/01/2000	1
3333	uvwx	M Rita Costa Santos	01/01/2000	1
5678	efgh	Maria Rita C Santos	01/01/2000	1
9101	ijkl	Rita Costa Santos	01/01/2000	1
1111	mnop	Maria Leonor Santos Silva	02/03/2001	2
2222	qrst	Leonor Santos Silva	02/03/2001	2
4444	yzab	Leonor Santos Silva	30/08/1999	3

Thank you in advance.

[PaigeMiller]

Can you describe further what you mean by "similar"?

[fcf]

Please read what I answered to draycut, it was the same question. Thank you!

[PeterClemmensen]

What does 'similar' mean here? That eg the spelling distance is not far from each other?

Also, is the data sorted by these 'likewise' names?

[fcf]

Similar, like in the examples. For example, the birth_date is the same for these:
- Maria Rita Costa Santos

- M Rita Costa Santos, the M is an abbreviation for Maria

- Rita Costa Santos - because Maria is such a popular name, the person chooses to only say the second name, which is less common.

However, these are all the same person, but just wrote the name in different ways. However, in the last two examples, people can have the same name and be different people (check the birth date).

[PeterClemmensen]

And you already have the ID for some of the obs? But not all, correct?

[fcf]

yes, not all 🙂 the point is to have the ids according to the same people, so I can group the data correctly

[PeterClemmensen]

Ok. Is your data sorted like this? Or could M Rita Costa Santos have an observation at the bottom?

[fcf]

It is not sorted. I just showed this so it would be easier to understand. I have like 12 000 records of names.

[PeterClemmensen]

Can a person have no ID with a pre-assigned value?

[fcf]

Can you elaborate please?

[PeterClemmensen]

The posted data you have is this:

data have;
infile datalines missover;
input num_A num_B $ name $ 11-36 birth_date :ddmmyy10. id;
format birth_date ddmmyy10.;
datalines;
1234 abcd M Rita Costa Santos        01/01/2000 1 
3333 uvwx M Rita Costa Santos        01/01/2000 1 
5678 efgh Maria Rita C Santos        01/01/2000   
9101 ijkl Rita Costa Santos          01/01/2000 1 
1111 mnop Maria Leonor Santos Silva  02/03/2001   
2222 qrst Leonor Santos Silva        02/03/2001 2 
4444 yzab Leonor Santos Silva        30/08/1999   
;

Can a situation arise, where a person in your data have no ID attached to any of its observations? See the two last obs in the data below (no ID)

data have;
infile datalines missover;
input num_A num_B $ name $ 11-36 birth_date :ddmmyy10. id;
format birth_date ddmmyy10.;
datalines;
1234 abcd M Rita Costa Santos        01/01/2000 1 
3333 uvwx M Rita Costa Santos        01/01/2000 1 
5678 efgh Maria Rita C Santos        01/01/2000   
9101 ijkl Rita Costa Santos          01/01/2000 1 
1111 mnop Maria Leonor Santos Silva  02/03/2001   
2222 qrst Leonor Santos Silva        02/03/2001 2 
4444 yzab Leonor Santos Silva        30/08/1999   
xxxx xxxx Some Name Here             01/01/1960   
xxxx xxxx Some Name Here             01/01/1960   
;

[fcf]

The only blank field possible would be the ID

[PeterClemmensen]

I will try to make myself more clear. Consider the data below. This is the same data that you posted plus an additional person.

While the two people in your initial data both have a pre-assigned ID (the one we want to hit for the remaining obs for those people), "Donald J Trump" does not. He is obviously not equal to either id=1 or id=2. 

Can this situation happen in your data? And then what?

data have;
infile datalines missover;
input num_A num_B $ name $ 11-36 birth_date :ddmmyy10. id;
format birth_date ddmmyy10.;
datalines;
1234 abcd M Rita Costa Santos        01/01/2000 1 
3333 uvwx M Rita Costa Santos        01/01/2000 1 
5678 efgh Maria Rita C Santos        01/01/2000   
9101 ijkl Rita Costa Santos          01/01/2000 1 
1111 mnop Maria Leonor Santos Silva  02/03/2001   
2222 qrst Leonor Santos Silva        02/03/2001 2 
4444 yzab Leonor Santos Silva        30/08/1999   
xxxx xxxx Donald J Trump             01/01/1960   
xxxx xxxx Donald J Trump             01/01/1960   
;

[fcf]

Ah yes, it can happen. That's why I gave the last example of a Leonor born in another date, which will have an id 3. The Donald Trump should be the id 4 for example.