Add preliminary documentation for database conversion

docs/utils.md

@@ -554,6 +554,27 @@ Show whitelist when using a [dynamic pairlist](plugins.md#pairlists).
 freqtrade test-pairlist --config config.json --quote USDT BTC
 ```
 
+## Convert database
+
+`freqtrade convert-db` can be used to convert your database from one system to another (sqlite -> postgres, postgres -> other postgres), migrating all trades, orders and Pairlocks.
+
+Please refer to the [SQL cheatsheet](sql_cheatsheet.md#use-a-different-database-system) to learn about requirements for different database systems.
+
+```
+usage: freqtrade convert-db [-h] [--db-url PATH] [--db-url-from PATH]
+
+optional arguments:
+  -h, --help          show this help message and exit
+  --db-url PATH       Override trades database URL, this is useful in custom
+                      deployments (default: `sqlite:///tradesv3.sqlite` for
+                      Live Run mode, `sqlite:///tradesv3.dryrun.sqlite` for
+                      Dry Run).
+  --db-url-from PATH  Source db url to use when migrating database systems.
+```
+
+!!! Warning
+    Please ensure to only use this on an empty target database. Freqtrade will perform a regular migration, but may fail if entries already existed.
+
 ## Webserver mode
 
 !!! Warning "Experimental"

freqtrade/commands/__init__.py

@@ -10,7 +10,7 @@ from freqtrade.commands.arguments import Arguments
 from freqtrade.commands.build_config_commands import start_new_config
 from freqtrade.commands.data_commands import (start_convert_data, start_convert_trades,
                                               start_download_data, start_list_data)
-from freqtrade.commands.db_commands import start_db_convert
+from freqtrade.commands.db_commands import start_convert_db
 from freqtrade.commands.deploy_commands import (start_create_userdir, start_install_ui,
                                                 start_new_strategy)
 from freqtrade.commands.hyperopt_commands import start_hyperopt_list, start_hyperopt_show

freqtrade/commands/arguments.py

@@ -82,7 +82,7 @@ ARGS_PLOT_DATAFRAME = ["pairs", "indicators1", "indicators2", "plot_limit",
 ARGS_PLOT_PROFIT = ["pairs", "timerange", "export", "exportfilename", "db_url",
                     "trade_source", "timeframe", "plot_auto_open", ]
 
-ARGS_INSTALL_DB = ["db_url", "db_url_from"]
+ARGS_CONVERT_DB = ["db_url", "db_url_from"]
 
 ARGS_INSTALL_UI = ["erase_ui_only", "ui_version"]
 
@@ -183,15 +183,14 @@ class Arguments:
         self._build_args(optionlist=['version'], parser=self.parser)
 
         from freqtrade.commands import (start_backtesting, start_backtesting_show,
-                                        start_convert_data, start_convert_trades,
+                                        start_convert_data, start_convert_db, start_convert_trades,
-                                        start_create_userdir, start_db_convert, start_download_data,
+                                        start_create_userdir, start_download_data, start_edge,
-                                        start_edge, start_hyperopt, start_hyperopt_list,
+                                        start_hyperopt, start_hyperopt_list, start_hyperopt_show,
-                                        start_hyperopt_show, start_install_ui, start_list_data,
+                                        start_install_ui, start_list_data, start_list_exchanges,
-                                        start_list_exchanges, start_list_markets,
+                                        start_list_markets, start_list_strategies,
-                                        start_list_strategies, start_list_timeframes,
+                                        start_list_timeframes, start_new_config, start_new_strategy,
-                                        start_new_config, start_new_strategy, start_plot_dataframe,
+                                        start_plot_dataframe, start_plot_profit, start_show_trades,
-                                        start_plot_profit, start_show_trades, start_test_pairlist,
+                                        start_test_pairlist, start_trading, start_webserver)
-                                        start_trading, start_webserver)
 
         subparsers = self.parser.add_subparsers(dest='command',
                                                 # Use custom message when no subhandler is added
@@ -379,11 +378,11 @@ class Arguments:
 
         # Add db-convert subcommand
         convert_db = subparsers.add_parser(
-            "db-convert",
+            "convert-db",
             help="Migrate database to different system",
         )
-        convert_db.set_defaults(func=start_db_convert)
+        convert_db.set_defaults(func=start_convert_db)
-        self._build_args(optionlist=ARGS_INSTALL_DB, parser=convert_db)
+        self._build_args(optionlist=ARGS_CONVERT_DB, parser=convert_db)
 
         # Add install-ui subcommand
         install_ui_cmd = subparsers.add_parser(

freqtrade/commands/db_commands.py

@@ -8,7 +8,7 @@ from freqtrade.enums.runmode import RunMode
 logger = logging.getLogger(__name__)
 
 
-def start_db_convert(args: Dict[str, Any]) -> None:
+def start_convert_db(args: Dict[str, Any]) -> None:
     from sqlalchemy.orm import make_transient
 
     from freqtrade.persistence import Trade, init_db

tests/commands/test_commands.py

@@ -14,7 +14,7 @@ from freqtrade.commands import (start_backtesting_show, start_convert_data, star
                                 start_list_exchanges, start_list_markets, start_list_strategies,
                                 start_list_timeframes, start_new_strategy, start_show_trades,
                                 start_test_pairlist, start_trading, start_webserver)
-from freqtrade.commands.db_commands import start_db_convert
+from freqtrade.commands.db_commands import start_convert_db
 from freqtrade.commands.deploy_commands import (clean_ui_subdir, download_and_install_ui,
                                                 get_ui_download_url, read_ui_version)
 from freqtrade.configuration import setup_utils_configuration
@@ -1462,13 +1462,13 @@ def test_backtesting_show(mocker, testdatadir, capsys):
     assert "Pairs for Strategy" in out
 
 
-def test_start_db_convert(mocker, fee, tmpdir, caplog):
+def test_start_convert_db(mocker, fee, tmpdir, caplog):
     db_src_file = Path(f"{tmpdir}/db.sqlite")
     db_from = f"sqlite:///{db_src_file}"
     db_target_file = Path(f"{tmpdir}/db_target.sqlite")
     db_to = f"sqlite:///{db_target_file}"
     args = [
-        "db-convert",
+        "convert-db",
         "--db-url-from",
         db_from,
         "--db-url",
@@ -1483,5 +1483,5 @@ def test_start_db_convert(mocker, fee, tmpdir, caplog):
     assert not db_target_file.is_file()
     pargs = get_args(args)
     pargs['config'] = None
-    start_db_convert(pargs)
+    start_convert_db(pargs)
     assert db_target_file.is_file()