def get_joins(self, table: Table, full: bool) -> List[JoinData]:
table_pk = self.model._meta.pk_db_column
through_table_name = "{}{}{}{}".format(table.get_table_name(), LOOKUP_SEP,
self.remote_model.__name__.lower(), self.model.__name__.lower())
through_table = Table(self.through).as_(through_table_name)
joins = [JoinData(
through_table,
through_table[self.backward_key] == table[table_pk],
through_table[self.backward_key],
None,
None,
)]
if full:
related_table = self.remote_model._meta.table(alias=self.join_table_alias(table))
related_field = self.remote_model._meta.pk
joins.append(JoinData(
related_table,
related_table[related_field.db_column] == through_table[self.forward_key],
related_table[related_field.db_column],
self.remote_model,
related_field
))
return joins
def parse_sources(self, config_name: str,
sources: List[Dict]) -> List[Dict]:
sql_sources = []
for source in sources:
if source.get("raw", None) is not None:
sql_sources.append(source["raw"])
else:
# sql query builder
table = Table(source["table"]["name"]).as_(source["table"].get(
"alias", source["table"]["name"]))
fields = []
for field in source["fields"]:
function = field.get("function", None)
if function is None:
value = Field(
field["name"].split(".")[1],
table=Table(field["name"].split(".")[0]),
).as_(field.get("alias", field["name"]))
if cast_is_required(field):
value = Cast(value, field.get("cast", None))\
.as_(field.get("alias", field["name"]))
fields.append(value)
else:
f = Field(
field["name"].split(".")[1],
table=Table(field["name"].split(".")[0]),
).as_(field.get("alias", field["name"]))
func = SQL_FUNCTION_MAPPING[function](f).as_(
field.get("alias", field["name"])).as_(
field.get("alias", field["name"]))
if cast_is_required(field):
func = Cast(func, field.get("cast", None))\
.as_(field.get("alias", field["name"]))
fields.append(func)
query = Query.from_(table)
# parse tables to join
for join_table_config in source.get("join", []):
join_table = Table(join_table_config["table"]["name"]).as_(
join_table_config["table"].get(
"alias", join_table_config["table"]["name"]))
# parse fields to join the table on
join_on_fields = []
for field in join_table_config["on"]:
table_name, field_name = field.split(".")
if table_name == join_table.get_table_name():
join_on_fields.append(
Field(field_name, table=join_table))
elif table_name == table.get_table_name():
join_on_fields.append(
Field(field_name, table=table))
else:
raise ExportConfigError(
f'ON field name "{field}" in configuration for "{config_name}" '
f'does not recognize table "{table_name}".')
if join_table_config[
"cond"] in COMPARISON_OPERATORS_MAPPING.keys():
on_cond = COMPARISON_OPERATORS_MAPPING[
join_table_config["cond"]](join_on_fields[0],
join_on_fields[1])
else:
on_cond = SQL_SPATIAL_JOIN_MAPPING[
join_table_config["cond"]](join_on_fields[0],
join_on_fields[1])
query = query.join(
join_table, JoinType[
join_table_config["type"].lower()]).on(on_cond)
# parse GROUP BY parameters
for group_by_field in source.get("group_by", []):
query = query.groupby(Field(group_by_field))
query = query.select(*fields)
# add RAW statements provided by a user
for raw_statement in [
source.get("filter", ""),
source.get("having", ""),
]:
if raw_statement:
query = str(query) + " " + raw_statement
# append SQL query string to the configuration sources
sql_sources.append(str(query))
return sql_sources
