One Time Scripts
These are scripts that are run exactly once per database, and never again. Think things like create table... statements. You can’t create a table twice so any attempt to run the script a second time results in an error.
Folders
Scripts in the following folders are one time scripts by default.
- runAfterCreateDatabase
- up
What goes in the Up Folder?
- DDL (schema changes - database structure)
- DML (inserts/updates/deletes)
How does the order work?
grate always runs files in order alphabetically.
How should I name my scripts?
One should prepend your order specific scripts with either a number moving upwards padded with three zeros (i.e. 0001_somescript.sql followed by 0002_nextscript.sql) or a nice long date time in YYYYMMddHHmmss format (i.e. 20121026091400_somescript.sql followed by 20121026091401_nextscript.sql), but you are not limited to those options. Some people do a separation by numbers as in ####.##.##.#### or something else. Find what works for you (and your team) and use it.
Errors
If there is a change to a one time script and the migrator is run, grate will determine you have changed that file and will shut down immediately with errors. That being said, there is a configuration setting to allow you to still run with warnings. Although not recommended, grate tries not to be a tool that constrains users.
See [[ConfigurationOptions]] under Switches WarnOnOneTimeScriptChanges