# Patches

Liquibase database migration changelogs. Two subdirectories — one per supported database:

```
patches/
  oracle/
    <timestamp>_<KEY>.xml
  postgresql/
    <timestamp>_<KEY>.xml
```

The filename convention is `{YYYYMMDDHHmm}_{MODULE_KEY}.xml` (e.g. `202604081221_GO.xml`).

Both files must always be kept in sync — every changeset must appear in both.

## Rules

- **Append-only.** Never edit or delete existing `<changeSet>` entries. Liquibase tracks executed changesets by `id` + `author`; modifying them breaks the checksum and will fail deployment. You can change conditions and order tho.
- **Unique IDs.** Each `<changeSet id="...">` must have a unique numeric ID within the file. Increment from the last existing one.
- **Use preConditions.** Wrap DDL in `<preConditions onFail="MARK_RAN">` guards so the changelog is idempotent and safe to re-run.
- **Oracle vs PostgreSQL syntax differs.** Sequences, data types, and quoting rules are different — write each file for its target DB. Don't copy-paste blindly between them.

## File skeleton

```xml
<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
  xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
                      http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.6.xsd">

  <changeSet author="your.name" id="401" objectQuotingStrategy="LEGACY">
    <preConditions onError="WARN" onFail="MARK_RAN" onSqlOutput="IGNORE">
      <not>
        <tableExists tableName="my_table" />
      </not>
    </preConditions>
    <sql endDelimiter=";" splitStatements="true" stripComments="false">
      CREATE TABLE my_table ( ... );
    </sql>
  </changeSet>

</databaseChangeLog>
```

## vitruvio.json registration

```json
"patches": [
  { "path": "patches" }
]
```