fetch.py
Fetch
¶
A fetch object that handles retrieving elements from the table expression.
:param expression: the QueryExpression object to fetch from.
Source code in datajoint/fetch.py
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__call__(*attrs, offset=None, limit=None, order_by=None, format=None, as_dict=None, squeeze=False, download_path='.')
¶
Fetches the expression results from the database into an np.array or list of dictionaries and unpacks blob attributes.
:param attrs: zero or more attributes to fetch. If not provided, the call will return all attributes of this relation. If provided, returns tuples with an entry for each attribute. :param offset: the number of tuples to skip in the returned result :param limit: the maximum number of tuples to return :param order_by: a single attribute or the list of attributes to order the results. No ordering should be assumed if order_by=None. To reverse the order, add DESC to the attribute name or names: e.g. ("age DESC", "frequency") To order by primary key, use "KEY" or "KEY DESC" :param format: Effective when as_dict=None and when attrs is empty None: default from config['fetch_format'] or 'array' if not configured "array": use numpy.key_array "frame": output pandas.DataFrame. . :param as_dict: returns a list of dictionaries instead of a record array. Defaults to False for .fetch() and to True for .fetch('KEY') :param squeeze: if True, remove extra dimensions from arrays :param download_path: for fetches that download data, e.g. attachments :return: the contents of the relation in the form of a structured numpy.array or a dict list
Source code in datajoint/fetch.py
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Fetch1
¶
Fetch object for fetching the result of a query yielding one row.
:param expression: a query expression to fetch from.
Source code in datajoint/fetch.py
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__call__(*attrs, squeeze=False, download_path='.')
¶
Fetches the result of a query expression that yields one entry.
If no attributes are specified, returns the result as a dict. If attributes are specified returns the corresponding results as a tuple.
Examples:
d = rel.fetch1() # as a dictionary a, b = rel.fetch1('a', 'b') # as a tuple
:params *attrs: attributes to return when expanding into a tuple. If attrs is empty, the return result is a dict :param squeeze: When true, remove extra dimensions from arrays in attributes :param download_path: for fetches that download data, e.g. attachments :return: the one tuple in the relation in the form of a dict
Source code in datajoint/fetch.py
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key
¶
object that allows requesting the primary key as an argument in expression.fetch() The string "KEY" can be used instead of the class key
Source code in datajoint/fetch.py
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to_dicts(recarray)
¶
convert record array to a dictionaries
Source code in datajoint/fetch.py
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