Caché Upgrade Checklists - InterSystems Documentation

Caché 2008.1 Upgrade Checklist8.3 DevelopersThis section contains information of interest to those who have designed, developed and maintained applications runningon prior versions of Caché.The items listed here are brief descriptions. In most cases, more complete descriptions are available elsewhere in the documentation.8.3.1 ObjectScript Changes8.3.1.1 $REPLACE Function AddedThis version of Caché adds a new string replacement function, $REPLACE. $REPLACE(S1, S2, S3) finds all occurrencesof the string S2 in the string S1 and replaces them with the string S3. All three arguments are required. Unlike$TRANSLATE, S2 and S3 are treated as complete strings, not lists of characters.8.3.1.2 $ZDATETIMEH Validation ImprovedIn this version, ODBC and SQL date-time validation is improved. $ZDATETIMEH will now report an error if any field(day, month, hour, second) is not in the proper format. For example, 002 will no longer be accepted as a valid day withina month because only two digits are allowed.8.3.2 SQL Changes8.3.2.1 Incompatibility: “arrow syntax” in ON clausesPrior to Version 2007.1, Caché SQL allowed use of arrow syntax in ON clauses. This was possible because Caché onlysupported a linear chain of left outer joins (one or more tables left joined to a single table). As a result, combinations ofarrow syntax, uses of =* syntax, and ANSI joins could readily be mixed within this very limited support.Arrow syntax has always been defined as equivalent to =* syntax, and uses the same underlying mechanism. As a result,it can no longer be supported ON clauses.All other support for arrow syntax remains (WHERE clause, SELECT clause, GROUP BY, ORDER BY, HAVING).8.3.2.2 Restriction on LEFT JOINThere remains a restriction with ON clauses with LEFT JOINs. If all the conditions affecting some table use comparisonsthat may pass null values, and that table is itself a target of an outer join, Caché may report:error 94: unsupported use of outer joinAn example of such a query isSELECT *FROM Table1LEFT JOIN Table2 ON Table1.k = Table2.kLEFT JOIN Table3 ON coalesce(Table1.k,Table2.k) = Table3.k8.3.2.3 Collation Order Now Applies to LIKEThe SQL LIKE operator now performs similarly to other comparison operators such as “=” and %STARTSWITH. Thatis, the expression:f LIKE 202 Caché Upgrade Checklists