# otp.Source.write #### Source.write(db, symbol=None, tick_type=None, date=adaptive, start_date=None, end_date=None, append=False, keep_symbol_and_tick_type=adaptive, propagate=True, out_of_range_tick_action='exception', timestamp=None, keep_timestamp=True, correction_type=None, replace_existing_time_series=False, allow_concurrent_write=False, context=adaptive, use_context_of_query=False, inplace=False, \*\*kwargs) Saves data result to OneTick database. * **Parameters:** * **db** (str or [`otp.DB`](../session/db.md#onetick.py.DB)) -- database name or object. * **symbol** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *or* [*Column*](../operation/root.md#onetick.py.Column)) -- resulting symbol name string or column to get symbol name from. If this parameter is not set, then ticks \_SYMBOL_NAME pseudo-field is used. If it is empty, an attempt is made to retrieve the symbol name from the field named SYMBOL_NAME. * **tick_type** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *or* [*Column*](../operation/root.md#onetick.py.Column)) -- resulting tick type string or column to get tick type from. If this parameter is not set, the \_TICK_TYPE pseudo-field is used. If it is empty, an attempt is made to retrieve the tick type from the field named TICK_TYPE. * **date** ([`otp.datetime`](../datetime/dt.md#onetick.py.datetime) or None) -- date where to save data. Should be set to None if writing to accelerator or memory database. By default, it is set to otp.config.default_date. * **start_date** ([`otp.datetime`](../datetime/dt.md#onetick.py.datetime) or None) -- Start date for data to save. It is inclusive. Cannot be used with `date` parameter. Also cannot be used with `inplace` set to `True`. Should be set to None if writing to accelerator or memory database. By default, None. * **end_date** ([`otp.datetime`](../datetime/dt.md#onetick.py.datetime) or None) -- End date for data to save. It is inclusive. Cannot be used with `date` parameter. Also cannot be used with `inplace` set to `True`. Should be set to None if writing to accelerator or memory database. By default, None. * **append** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If False - data will be rewritten for this `date` or range of dates (from `start_date` to `end_date`), otherwise data will be appended: new symbols are added, existing symbols can be modified (append new ticks, modify existing ticks). This option is not valid for accelerator databases. * **keep_symbol_and_tick_type** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- keep fields containing symbol name and tick type when writing ticks to the database or propagating them. By default, this parameter is adaptive. If `symbol` or `tick_type` are column objects, then it's set to True. Otherwise, it's set to False. * **propagate** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- Propagate ticks after that event processor or not. * **out_of_range_tick_action** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) -- Action to be executed if tick's timestamp's date is not `date` or between `start_date` or `end_date`: > * exception: runtime exception will be raised > * ignore: tick will not be written to the database > * load: writes tick to the database anyway. > : Can be used only with `date`, not with `start_date``+``end_date`. Default: exception * **timestamp** ([*Column*](../operation/root.md#onetick.py.Column)) -- Field that contains the timestamp with which the ticks will be written to the database. By default, the TIMESTAMP pseudo-column is used. * **keep_timestamp** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If `timestamp` parameter is set and this parameter is set to True, then timestamp column is removed. * **correction_type** ([*Column*](../operation/root.md#onetick.py.Column)) -- The name of the column that contains the correction type. This column will be removed. If this parameter is not set, no corrections will be submitted. * **replace_existing_time_series** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If `append` is set to True, setting this option to True instructs the loader to replace existing time series, instead of appending to them. Other time series will remain unchanged. * **allow_concurrent_write** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- Allows different queries running on the same server to load concurrently into the same database. * **context** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) -- The server context used to look up the database. By default, otp.config.context is used if `use_context_of_query` is not set. * **use_context_of_query** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- If this parameter is set to True and the `context` parameter is not set, the context of the query is used instead of the default value of the `context` parameter. * **inplace** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) -- A flag controls whether operation should be applied inplace. If `inplace=True`, then it returns nothing. Otherwise, method returns a new modified object. Cannot be `True` if `start_date` and `end_date` are set. * **kwargs** -- #### Deprecated Deprecated since version 1.21.0. Use named parameters instead. * **Return type:** [`Source`](root.md#onetick.py.Source) or None #### NOTE This method does not save anything. It adds instruction in query to save. Data will be saved when query will be executed. Using `start``+``end` parameters instead of single `date` have some limitations: > * `inplace` is not supported > * if `DAY_BOUNDARY_TZ` and `DAY_BOUNDARY_OFFSET` specified against > : individual locations of database, then day boundary could be calculated incorrectly. > * `out_of_range_tick_action` could be only `exception` or `ignore` ### Examples ```pycon >>> data = otp.Ticks(X=[1, 2, 3]) >>> data = data.write('SOME_DB', symbol='S_WRITE', tick_type='T_WRITE') >>> otp.run(data) Time X 0 2003-12-01 00:00:00.000 1 1 2003-12-01 00:00:00.001 2 2 2003-12-01 00:00:00.002 3 >>> data = otp.DataSource('SOME_DB', symbol='S_WRITE', tick_type='T_WRITE') >>> otp.run(data) Time X 0 2003-12-01 00:00:00.000 1 1 2003-12-01 00:00:00.001 2 2 2003-12-01 00:00:00.002 3 ``` #### SEE ALSO **WRITE_TO_ONETICK_DB** OneTick event processor