Database I/O subpackage¶

All functions of datesy taking care of database I/O are listed here. The functionality is the same for all supported database types. Simply exchange _db_helper.Database with the desired database.

Database¶

class datesy.database_IO._db_helper.Database(host, port, user, password, database, auto_creation=False)¶

Representing a database as an object

On initialization the connection to the database is established. For clean working please call close() at end of db usage.

Parameters:	host (str) – url or ip of host port (int) – port_no user (str) – user_name password (str) – password for this user database (str) – the database to connect to auto_creation (bool, optional) – if all tables shall be initiated as variables of object kwargs – specific information to database, see details to each database

close()¶: Close connection to database

name¶

Name of the database

Returns:
Return type:	str

table(table_name)¶

Return a database_table as an object

Parameters:	table_name (str) – the desired table
Returns:	class Table as representation of table
Return type:	Table

tables¶

Get the available tables of database

Returns:	representing all tables of database
Return type:	list

update_table_data()¶

Update the data concerning the list of available tables

Returns:	available tables at database
Return type:	list

Table¶

class datesy.database_IO._db_helper.Table(table_name, database)¶

Create a representation of a database table

Parameters:	table_name (str) – database (Database) –

__getitem__(key)¶

Get row of primary key

works like value = database.table[key]

Parameters:	key (any) – matching value in primary column
Returns:	tuple items representing every matched row in database
Return type:	Row

__setitem__(primary_key, row)¶

Set/update a single row for primary key

works like database.table[key] = row

Parameters:	primary_key (any, None) – the value of the primary column. If None -> new row inserted row (list, dict) – the row data in either correct order or in a dict with column_name

__delitem__(key)¶

Delete single row for given primary key

works like del database.table[key]

Parameters:	key (any) – matching value in primary column

delete_where(*args, **kwargs)¶

Delete rows matching the where conditions

Parameters:	args (conditions) – kwargs (conditions) –

execute_raw_sql(sql_query)¶

Execute raw sql statements

Parameters:	sql_query (str) – sql query
Returns:	data from database
Return type:	list

get_where(*args, **kwargs)¶

Get rows where value matches the defined column: columns=key

Parameters:	**kwargs – column = key values
Returns:	tuple items representing every matched row in database
Return type:	list(Row)

insert(row: (<class 'list'>, <class 'dict'>), primary_key=None)¶

Insert new row

Parameters:	row (list, dict) – row_data primary_key (any, optional) – primary_key optional for tables with primary_key

primary¶

Get the primary key of this table

Returns:	the primary column as string if one exists
Return type:	str, None

run_query(debug=False)¶

Run the currently composed query :param debug: if the query shall be printed to command_line :type debug: bool, optional

Returns:	data from database
Return type:	list

schema¶

Get schema of table

Returns:	dictionary containing the column as key and schema_info as dictionary for every column
Return type:	OrderedDict

update_primary_data()¶

Update the primary key of the table

Returns:	the primary column as string if one exists
Return type:	str, None

update_schema_data()¶

Update the schema of the table

Returns:	dictionary containing the column as key and schema_info as dictionary for every column
Return type:	OrderedDict

update_where(values: (<class 'list'>, <class 'dict'>), *args, primary_key=None, limit_rows: int = False, **kwargs)¶

Update all rows based on given conditions

Parameters:	values (list, dict) – new values to set. either as a full row in a list or specified columns with dictionary args – conditions primary_key (any, optional) – the value of the primary column (if table has primary_key) limit_rows (int) – number of rows to affect kwargs – conditions

Row¶

class datesy.database_IO._db_helper.Row(table, data)¶

Representation of a database row entry

Parameters:	table (Table) – table belonging to data (list, tuple, dict) – data to represent

__getitem__(column)¶

Get column_value of row

works like value = database.table.row[column]

Parameters:	column (int, str) – position in table or column_name
Returns:
Return type:	Item

__setitem__(column, value)¶

Set new value to column

works like database.table.row[column] = value

Parameters:	column (int, str) – position in table or column_name value (any) – new value

__delitem__(column)¶

Delete/reset to default a column

works like del database.table.row[column]

Parameters:	column (int, str) – position in table or column_name

sync(*missing_columns)¶

Update row from database to local

Parameters:	missing_columns (str, optional) – if rows shall be left out when updating (e.g. if known that a timestamp has changed and it shall be fetched)

Item¶

class datesy.database_IO._db_helper.Item(row, column, table, value=None)¶

Representation of a database entry

Parameters:	row (Row) – column (str) – table (Table) – value (any) –

__set__(instance, value)¶

Set new value

Parameters:	instance – value (any) – new value

__delete__(instance)¶: Delete/reset to default this value

column¶

Column this item belonging to

Returns:	column
Return type:	str

database¶

Database this item is belonging to

Returns:	database
Return type:	Database

sync()¶: Update entry from database to local

table¶

Table this item is belonging to

Returns:	table
Return type:	Table

value¶

Value of this item

Returns:	value
Return type:	any