def _get_classid_for_dataset(connection, dataset_id, class_name):
query = sqlalchemy.text("""
SELECT id
FROM dataset_class
WHERE name = :name
AND dataset = :dataset_id""")
result = connection.execute(query, {
"name": class_name,
"dataset_id": dataset_id
})
if result.rowcount < 1:
raise exceptions.NoDataFoundException("No such class exists.")
clsid = result.fetchone()
return clsid[0]
def create_snapshot(dataset_id):
"""Creates a snapshot of current version of a dataset.
Snapshots are stored as JSON and have the following structure:
{
"name": "..",
"description": "..",
"classes": [
{
"name": "..",
"description: "..",
"recordings": ["..", ...]
},
...
]
}
Args:
dataset_id (string/uuid): ID of a dataset.
Returns:
ID (UUID) of a snapshot that was created.
"""
dataset = get(dataset_id)
if not dataset:
raise exceptions.NoDataFoundException(
"Can't find dataset with a specified ID.")
snapshot = {
"name":
dataset["name"],
"description":
dataset["description"],
"classes": [{
"name": c["name"],
"description": c["description"],
"recordings": c["recordings"],
} for c in dataset["classes"]],
}
with db.engine.connect() as connection:
result = connection.execute(
sqlalchemy.text("""
INSERT INTO dataset_snapshot (id, dataset_id, data)
VALUES (uuid_generate_v4(), :dataset_id, :data)
RETURNING id::text
"""), {
"dataset_id": dataset_id,
"data": json.dumps(snapshot),
})
return result.fetchone()["id"]
def get(id):
"""Get dataset with a specified ID.
Returns:
Dictionary with dataset details if it has been found, None
otherwise.
"""
with db.engine.connect() as connection:
result = connection.execute(
"SELECT id::text, name, description, author, created, public, last_edited "
"FROM dataset "
"WHERE id = %s", (str(id), ))
if result.rowcount < 1:
raise exceptions.NoDataFoundException(
"Can't find dataset with a specified ID.")
row = dict(result.fetchone())
row["classes"] = _get_classes(row["id"])
return row