Rebuilding a .cdx from scratch (DELETE TAG ALL, then rebuilding each tag) will delete all your persistent relationships in the .dbc, and if you haven't stored your PRIMARY and CANDIDATE index metadata, as well as testing for it when rebuilding your index tags, all your index tags will be type 'Regular'.
At first, it's easy to just think we'll rebuild index tags without deleting them first. But sooner or later, we know we will have to rebuild them from scratch. Here's some ideas about how to solve this challenge.
********************************* ** Assumes you already have a table of metadata, including ** index tag names, index expressions and if ** an index is a primary or candidate index ********************************* ** BEFORE YOU DELETE TAGS AND REINDEX, CAPTURE THE RELATIONS ** IN THE .DBC SO YOU CAN RESTORE THEM LATER. USE myDatabase.DBC AGAIN SHARED IN 0 ALIAS zDBC SELECT *, RECNO() AS 'RECORDNO' ; FROM zDBC ; WHERE UPPER(ALLTRIM(objecttype)) == 'RELATION' ; AND !DELETED() ; INTO CURSOR zRels ****************************************** ** PUT YOUR REINDEXING METHOD HERE AND INCLUDE THE FOLLOWING CODE: ****************************************** ****************************************** ** aIndexExpr is an array SELECTed from the metadata file where ** Column1 = TAG NAME [from TAG()] ** Column2 = INDEX EXPRESSION [from SYS(14) and SYS(2021)] ** plus a ## tag indicating if the index is a ** ##CANDIDATE## [from CANDIDATE()] ** or ##PRIMARY## key [from PRIMARY()] ** ** lcTable is already USED EXCLUSIVELY and SELECTed ** DELETE TAG ALL FOR x=1 TO ALEN(aIndexExpr,1) && rebuild each tag m.cIndExpr = ALLTRIM(aIndexExpr[x,2]) DO CASE CASE '##PRIMARY##' $ m.cIndExpr m.cIndExpr = STRTRAN(m.cIndExpr,'##PRIMARY##','') lcExpr = (ALLTRIM(aIndexExpr[x,1])) ALTER TABLE (lcTable) ; ADD PRIMARY KEY &lcExpr TAG (ALLTRIM(aIndexExpr[x,1])) CASE '##CANDIDATE##' $ m.cIndExpr m.cIndExpr = STRTRAN(m.cIndExpr,'##CANDIDATE##','') &cIndExpr CANDIDATE OTHERWISE &cIndExpr ENDCASE ENDFOR ****************************************** ** FINISH YOUR REINDEXING METHOD HERE ****************************************** ** now recall the deleted relations in the dbc ** (this example assumes SET DELETED ON) SELECT zRels SET DELETED OFF ** .dbc was already opened ALIAS zDBC earlier SCAN GO (zRels.RecordNo) IN zDBC IF DELETED('zDBC') SELECT ('zDBC') RECALL NEXT 1 SELECT zRels ENDIF ENDSCAN USE IN zDBC USE IN zRels SET DELETED ON ********************************* ** end *********************************
