vikunja-api/docs/content/doc/development/db-migrations.md
2021-07-14 00:25:12 +02:00

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---
date: "2019-03-29:00:00+02:00"
title: "Database Migrations"
draft: false
type: "doc"
menu:
sidebar:
parent: "development"
---
# Database Migrations
Vikunja runs all database migrations automatically on each start if needed.
Additionally, they can also be run directly by using the `migrate` command.
We use [xormigrate](https://github.com/techknowlogick/xormigrate) to handle migrations,
which is based on gormigrate.
{{< table_of_contents >}}
## Add a new migration
All migrations are stored in `pkg/migrations` and files should have the same name as their id.
Each migration should have a function to apply and roll it back, as well as a numeric id (the datetime)
and a more in-depth description of what the migration actually does.
To easily get a new id, run the following on any unix system:
{{< highlight bash >}}
date +%Y%m%d%H%M%S
{{< /highlight >}}
New migrations should be added via the `init()` function to the `migrations` variable.
All migrations are sorted before being executed, since `init()` does not guarantee the order.
When you're adding a new struct, you also need to add it to the `models.GetTables()` function
to ensure it will be created on new installations.
### Generating a new migration stub
You can easily generate a pre-filled migration stub by running `mage dev:make-migration`.
It will ask you for a table name and generate an empty migration similar to the example shown below.
### Example
{{< highlight golang >}}
package migration
import (
"github.com/go-xorm/xorm"
"src.techknowlogick.com/xormigrate"
)
// Used for rollback
type teamMembersMigration20190328074430 struct {
Updated int64 `xorm:"updated"`
}
func (teamMembersMigration20190328074430) TableName() string {
return "team_members"
}
func init() {
migrations = append(migrations, &xormigrate.Migration{
ID: "20190328074430",
Description: "Remove updated from team_members",
Migrate: func(tx *xorm.Engine) error {
return dropTableColum(tx, "team_members", "updated")
},
Rollback: func(tx *xorm.Engine) error {
return tx.Sync2(teamMembersMigration20190328074430{})
},
})
}
{{< /highlight >}}
You should always copy the changed parts of the struct you're changing when adding migraitons.