Link two tables with a date year and month

[WilliamB]

Hello I would like to connect 2 tables but I do not know how to do it because of the date in text of the second table $ 6 ..
Can you help me.

Table 1				Table 2
COMAX	COOPU	DAOPU		COMAX	Comois
37351	OPUCTC00046D2CW	02-juil-19		37351	201907
42235	OPUCTC0004TOCFP	05-nov-19		42235	201911
42235	OPUCTC0004UJ9RI	26-déc-19		42243	202001
42243	OPUCTC0004XHLP6	10-janv-20		42251	201911
42251	OPUCTC0004UJD3G	19-nov-19		42265	201912
42265	OPUCTC0004U8XL6	20-déc-19		42268	201911
42268	OPUCTC0004TOJYV	26-nov-19		103891	201909
103891	OPUCTC0004OCEP1	15-sept-19
42265	OPUCTC0004U8XL6	20-janv-19

Want
COMAX	Comois	COOPU
37351	201907	OPUCTC00046D2CW
42235	201911	OPUCTC0004TOCFP
42243	202001	OPUCTC0004XHLP6
42251	201911	OPUCTC0004UJD3G
42265	201912	OPUCTC0004U8XL6
42268	201911	OPUCTC0004TOJYV
103891	201909	OPUCTC0004OCEP1

[Kurt_Bremser · Accepted solution]

Create a comois variable in the first table, and join on that:

data table1;
input comax :$5. coopu :$20. daopu :yymmdd10.;
comois = put(daopu,yymmn6.);
datalines;
37351 OPUCTC00046D2CW 2019-07-02
42235 OPUCTC0004TOCFP 2019-11-05
42235 OPUCTC0004UJ9RI 2019-12-26
;

data table2;
input comax :$5. comois :$6.;
datalines;
37351 201907
42235 201911
;

proc sql;
create table want as
select t1.comax, t2.comois, t1.coopu
from table1 t1, table2 t2
where t1.comax = t2.comax and t1.comois = t2.comois;
quit;

Please supply example data in usable form (see the above for reference), so we know exactly what you're talking about.