See the sample program.
DBIAccessor is a glue class between the DBBackedClass object
space and the database itself. While rarely used directly, it provides
the engine for DBBackedClasses to reconstitute instances from data in
the database, create new database records from new instances, and
delete existing instances from the database.
DBIAccessor.new(dbh, query_strings)Constructs a new DBIAccessor instance, talking to the database
attached to the DBI database handle dbh with the query
strings being a hash of tags to parameterized SQL query strings. This
allows DBIAccessor to be database independent, in the true
spirit of DBI. Want to backend with a different DB? Just drop
in a new set of query strings and pass a database handle to that new
database.
You will probably never use any of these directly. Rather they get
called by instances of DBBackedClass.
DBIAccessor#selexec2(stmt, *params)Execute the statement stmt with the parameters params (an arbitrary number of parameters to the method). Results are return as an array of rows. Each row is a hash of keys (field names) to values.
DBIAccessor#selexec(query, *params)This is similar to DBIAccessor#selexec2 only query is the
shorthand tag for one of the queries in the query string hash. The
appropriate query is looked up and then it and the parameters are
passed to selexec2.
DBIAccessor#listByType(klass, modifier=nil)List all instances of type klass where klass is an
instance of Class. Optionally modifier may be a non-null
string modifying the query. An array of results is returned.
DBIAccessor#lookupByTypeAndID(klass, record_id)Lookup a particular instance/record from the table klass by
record ID where klass is an instance of Class. Return the
result as an array of rows where each row is a hash of key (field name)
=> value.
DBIAccessor#lookupByAttributes(object)Given an object object, we try to find all rows that look like it
(by looking at the attributes that are actually defined for
object). Return the results as an array of rows where each row
is a hash of key (field name) => value.
DBIAccessor#lookupLastInsert(object)Lookup the last record insert into the table which stores instances of
the same class as object. Used internally by DBIAccessor.
DBIAccessor#insert(object)Insert object into the table. Fails if an instance with the same
record ID already exists.
DBIAccessor#update(object)Update object in the database.
DBIAccessor#delete(object)Delete object from the database.