SDSQL  SQL statement object

    S=SDSQL(D,STR)  % create SQL statement in database D
    S2=SDSQL(S2,STR)  % update existing SQL statement S

 INPUT
   D     SDDB database object
   S2    Existing SDSQL object (already opened statement)
   STR   SQL statement

 OUTPUT
   S,S2  Created SQL statement

 DESCRIPTION
 SDSQL represents an SQL statement performed on a data set D.  SELECT
 statements are prepared (compiled) and executed only later, when the
 object S is converted into cell array or data set.  Other types of
 statements (such as INSERT or CREATE) are executed directly.

 SEE ALSO
 SDDB