# sync() is called.
primary_key = None
- # Set this to a dict of the valid fields of this object. Not all
- # fields (e.g., joined fields) may be updated via sync().
+ # Set this to the names of tables that reference this table's
+ # primary key.
+ join_tables = []
+
+ # Set this to a dict of the valid fields of this object and their
+ # types. Not all fields (e.g., joined fields) may be updated via
+ # sync().
fields = {}
+ def __init__(self, api, fields = {}):
+ dict.__init__(self, fields)
+ self.api = api
+
def validate(self):
"""
Validates values. Will validate a value with a custom function
validate = getattr(self, 'validate_' + key)
self[key] = validate(value)
- def sync(self, commit = True):
+ def sync(self, commit = True, insert = None):
"""
Flush changes back to the database.
"""
keys = fields.keys()
values = [self.api.db.param(key, value) for (key, value) in fields.items()]
- if not self.has_key(self.primary_key):
+ # If the primary key (usually an auto-incrementing serial
+ # identifier) has not been specified, or the primary key is the
+ # only field in the table, or insert has been forced.
+ if not self.has_key(self.primary_key) or \
+ all_fields == [self.primary_key] or \
+ insert is True:
# Insert new row
- sql = "INSERT INTO %s (%s) VALUES (%s);" % \
+ sql = "INSERT INTO %s (%s) VALUES (%s)" % \
(self.table_name, ", ".join(keys), ", ".join(values))
else:
# Update existing row
def delete(self, commit = True):
"""
- Delete row from its primary table.
+ Delete row from its primary table, and from any tables that
+ reference it.
"""
assert self.primary_key in self
- sql = "DELETE FROM %s" % self.table_name + \
- " WHERE %s = %s" % \
- (self.primary_key,
- self.api.db.param(self.primary_key, self[self.primary_key]))
+ for table in self.join_tables + [self.table_name]:
+ if isinstance(table, tuple):
+ key = table[1]
+ table = table[0]
+ else:
+ key = self.primary_key
- self.api.db.do(sql, self)
+ sql = "DELETE FROM %s WHERE %s = %s" % \
+ (table, key,
+ self.api.db.param(self.primary_key, self[self.primary_key]))
+
+ self.api.db.do(sql, self)
if commit:
self.api.db.commit()
-class Table(dict):
+class Table(list):
"""
Representation of row(s) in a database table.
"""
+ def __init__(self, api, row, columns = None):
+ self.api = api
+ self.row = row
+
+ if columns is None:
+ columns = row.fields
+ else:
+ columns = filter(lambda x: x in row.fields, columns)
+ if not columns:
+ raise PLCInvalidArgument, "No valid return fields specified"
+
+ self.columns = columns
+
def sync(self, commit = True):
"""
Flush changes back to the database.
"""
- for row in self.values():
+ for row in self:
row.sync(commit)
+
+ def selectall(self, sql, params = None):
+ """
+ Given a list of rows from the database, fill ourselves with
+ Row objects.
+ """
+
+ for row in self.api.db.selectall(sql, params):
+ self.append(self.row(self.api, row))