feat: initial header for mp_stackdiffs. Introduces a dependency on DOT (graphviz) for doc generation.

base/mp_coretable.sas

@@ -10,6 +10,8 @@
       %mp_coretable(LOCKTABLE,libds=work.locktable)
 
   @param [in] table_ref The type of table to create.  Example values:
+    @li DIFFTABLE - Used to store changes to tables.  Used by mp_storediffs.sas
+      and mp_stackdiffs.sas
     @li FILTER_DETAIL - For storing detailed filter values.  Used by
       mp_filterstore.sas.
     @li FILTER_SUMMARY - For storing summary filter values.  Used by
@@ -25,6 +27,8 @@
   @li mp_filterstore.sas
   @li mp_lockanytable.sas
   @li mp_retainedkey.sas
+  @li mp_storediffs.sas
+  @li mp_stackdiffs.sas
 
   @version 9.2
   @author Allan Bowe
@@ -36,7 +40,29 @@
 %local outds ;
 %let outds=%sysfunc(ifc(&libds=0,_data_,&libds));
 proc sql;
-%if &table_ref=LOCKTABLE %then %do;
+%if &table_ref=DIFFTABLE %then %do;
+  create table &outds(
+      load_ref char(36) label='unique load reference',
+      processed_dttm num format=E8601DT26.6 label='Processed at timestamp',
+      libref char(8) label='Library Reference (8 chars)',
+      dsn char(32) label='Dataset Name (32 chars)',
+      key_hash char(32) label=
+        'MD5 Hash of primary key values (pipe seperated)',
+      move_type char(1) label='Either (A)ppended, (D)eleted or (M)odified',
+      is_pk num label='Is Primary Key Field? (1/0)',
+      is_diff num label=
+        'Did value change? (1/0/-1).  Always -1 for appends and deletes.',
+      tgtvar_type char(1) label='Either (C)haracter or (N)umeric',
+      tgtvar_nm char(32) label='Target variable name (32 chars)',
+      oldval_num num format=best32. label='Old (numeric) value',
+      newval_num num format=best32. label='New (numeric) value',
+      oldval_char char(32765) label='Old (character) value',
+      newval_char char(32765) label='New (character) value',
+    constraint pk_mpe_audit
+      primary key(load_ref,libref,dsn,key_hash,tgtvar_nm)
+  );
+%end;
+%else %if &table_ref=LOCKTABLE %then %do;
   create table &outds(
       lock_lib char(8),
       lock_ds char(32),