How to reshape a table having multiple records for the same id into a table with one record per id without losing information? - sql

Question

Basically, I want to transform this(Initial) into this(Final). In other words, I want to
"squash" the initial table so that it will have only one record per id
"dilate" the initial table so that I won't lose any information: create a different column for every possible combination of source and column from the initial table (create c1_A, c1_B, ...).
I can work with the initial table as a csv in Python (maybe Pandas) and manually hardcode the mapping between the Initial and the Final table. However, I don't find this solution elegant at all and I'm much more interested in a sql / sas solution. Is there any way of doing that?
Edit: I what to change
+----+--------+------+-----+------+
| ID | source | c1 | c2 | c3 |
+----+--------+------+-----+------+
| 1 | A | 432 | 56 | 1 |
| 1 | B | 53 | 3 | 73 |
| 1 | C | 7 | 342 | 83 |
| 1 | D | 543 | 43 | 73 |
| 2 | A | 8 | 882 | 39 |
| 2 | B | 5 | 54 | 46 |
| 2 | C | 8 | 3 | 2226 |
| 2 | D | 87 | 2 | 45 |
| 3 | A | 93 | 143 | 45 |
| 3 | B | 1023 | 72 | 8 |
| 3 | C | 3 | 3 | 704 |
| 4 | A | 2 | 5 | 0 |
| 4 | B | 78 | 888 | 2 |
| 4 | C | 87 | 23 | 34 |
| 4 | D | 112 | 7 | 712 |
+----+--------+------+-----+------+
into
+----+------+------+------+------+------+------+------+------+------+------+------+------+
| ID | c1_A | c1_B | c1_C | c1_D | c2_A | c2_B | c2_C | c2_D | c3_A | c3_B | c3_C | c3_D |
+----+------+------+------+------+------+------+------+------+------+------+------+------+
| 1 | 432 | 53 | 7 | 543 | 56 | 3 | 342 | 43 | 1 | 73 | 83 | 73 |
| 2 | 8 | 5 | 8 | 87 | 882 | 54 | 3 | 2 | 39 | 46 | 2226 | 45 |
| 3 | 93 | 1023 | 3 | | 143 | 72 | 3 | | 45 | 8 | 704 | |
| 4 | 2 | 78 | 87 | 112 | 5 | 888 | 23 | 7 | 0 | 2 | 34 | 712 |
+----+------+------+------+------+------+------+------+------+------+------+------+------+

Answer 1

Abandon hope ... ?
data want;
input
ID source $ c1 c2 c3;datalines;
1 A 432 56 1
1 B 53 3 73
1 C 7 342 83
1 D 543 43 73
2 A 8 882 39
2 B 5 54 46
2 C 8 3 2226
2 D 87 2 45
3 A 93 143 45
3 B 1023 72 8
3 C 3 3 704
4 A 2 5 0
4 B 78 888 2
4 C 87 23 34
4 D 112 7 712
;
* one to grow you oh data;
proc transpose data=want out=stage1;
by id source;
var c1-c3;
run;
* and one to shrink;
proc transpose data=stage1 out=want(drop=_name_) delim=_;
by id;
id _name_ source;
run;