Using Caché Objects - InterSystems Documentation

Query Basics
Final
Specifies that subclasses cannot override the query. By default, queries are not final.
SQLQuery
SQLProc
Specifies the code to execute when the query is run. Use this keyword if the query
uses SQL (that is, is not user-written).
Specifies that the query can also be accessed as an SQL stored procedure. By default,
a query is not projected as a stored procedure.
Type
Specifies whether the query contains SQL or Caché ObjectScript code. By default,
the query contains SQL code.
8.1.3 Creating a Class Query Specification
A query needs to contains information about its contents and the order of the fields returned
for each row of its results. To provide this information, user-written queries include what is
called a specification.
A specification has one or two parameters modifying the query. These parameters are:
• CONTAINID — This optional parameter specifies which field, if any, contains the ID
for a particular row.
• ROWSPEC — This parameter provides information on the names, data types, headings,
and order of the fields in each row of the query's result set.
8.1.3.1 About CONTAINID
CONTAINID should be set to the number of the column returning the ID (1, by default) or
to 0 if no column returns the ID. If you create a query using the New Query Wizard, then
Studio automatically assigns the appropriate value to CONTAINID, based on the order in
that wizard's Columns page.
Note:
Caché does not validate the value of CONTAINID. If you specify a non-valid value
for this parameter, Caché does not throw an error. This means that if your query
processing logic depends on this information, you may experience inconsistencies
if the CONTAINID parameter is set improperly.
Using Caché Objects 57