gotosocial/internal/db/bundb/migrations/README.md

70 lines
2.0 KiB
Markdown

# Migrations
## How do I write a migration file?
[See here](https://bun.uptrace.dev/guide/migrations.html#migration-names)
As a template, take one of the existing migration files and modify it, or use the below code snippet:
```go
// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package migrations
import (
"context"
"github.com/uptrace/bun"
)
func init() {
up := func(ctx context.Context, db *bun.DB) error {
return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
// your logic here
return nil
})
}
down := func(ctx context.Context, db *bun.DB) error {
return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
// your logic here
return nil
})
}
if err := Migrations.Register(up, down); err != nil {
panic(err)
}
}
```
## File format
Bun requires a very specific format: 14 digits, then letters or underscores.
You can use the following bash command on your branch to generate a suitable migration filename.
```bash
echo "$(date --utc +%Y%m%d%H%M%S | head -c 14)_$(git rev-parse --abbrev-ref HEAD).go"
```
## Rules of thumb
1. **DON'T DROP TABLES**!!!!!!!!
2. Don't make something `NOT NULL` if it's likely to already contain `null` fields.