defquery is a mini-language for defining interactive database queries
Any enterprise app that I've worked on has many "search" screens that provide users with an easy way to execute canned queries against the operational data. I've found that the ORM frameworks out there don't support these screens very well because they are more concerned with creating and updating individual records and listing related records. In contrast, "search" screens typically gather data from several tables, filter it (sometimes using fairly complex predicates), and present a table of results (with bonus points for exporting the results in a variety of formats). This library provides a mini-language to spec out these screens together with a simple web interface.
- Postmodern (and implicitly the PostgreSQL database) S-XML
- hunchentoot slickgrid
###defquery
Defines a new query named `query-name' in the global envioronment. The body of the query consists of the following options
A boolean expression tree consisting of sub-predicates that may be combined using traditional primitive booleans like "and", "or" "<", ">" etc. e.g. (:and (:> date-from) (:< date-thru))
=> (:and (:> date-from ?) (:< date-thru ?))
We add value over plain SQL by evaluating the predicate only once we've got all the input from the user so if the user does not specify some parameter, that sub-predicate is replaced in our expression by "true".
A SQL view, table, or S-SQL table expression that minimally provides a column for each predicate mentioned in the :predicate clause above. It may provide additional columns but these are ignored by defquery. It should also provide a `key' which we will be used to search the
A SQL view, table, or S-SQL table expression that provides the data one wishes the user to see when displaying the query results.
A user-interface definition that specifies the ui controls necessary to elicit the query's input parameters from the user. The default implementation renders these using HTML and javascript but there should be nothing to prevent these ui controls being rendered by a desktop widget library like LtK or GtK.
A user-interface definition that specifies the ui control(s) necessary to display the query result. The default implementation uses the javascript library slickgrid but again, other implementations should be
possible.