Migration Scripts
These scripts are executed against the current database on server start-up. Any scripts previously executed are skipped, however these scripts are designed to be idempotent for Postgres and MySQL. To correct common problems with schema and data migrations the focalboard_schema_migrations
table can be cleared of all records and the server restarted.
The following built-in variables are available:
Name | Syntax | Description |
---|---|---|
schemaName | {{ .schemaName }} | Returns the database/schema name (e.g. mattermost_ , mattermost_test , public , ...) |
prefix | {{ .prefix }} | Returns the table name prefix (e.g. focalbaord_ ) |
postgres | {{if .postgres }} ... {{end}} | Returns true if the current database is Postgres. |
sqlite | {{if .sqlite }} ... {{end}} | Returns true if the current database is Sqlite3. |
mysql | {{if .mysql }} ... {{end}} | Returns true if the current database is MySQL. |
plugin | {{if .plugin }} ... {{end}} | Returns true if the server is currently running as a plugin (or product). In others words this is true if the server is not running as stand-alone or personal server. |
singleUser | {{if .singleUser }} ... {{end}} | Returns true if the server is currently running in single user mode. |
To help with creating scripts that are idempotent some template functions have been added to the migration engine.
Name | Syntax | Description |
---|---|---|
addColumnIfNeeded | {{ addColumnIfNeeded schemaName tableName columnName datatype constraint }} | Adds column to table only if column doesn't already exist. |
dropColumnIfNeeded | {{ dropColumnIfNeeded schemaName tableName columnName }} | Drops column from table if the column exists. |
createIndexIfNeeded | {{ createIndexIfNeeded schemaName tableName columns }} | Creates an index if it does not already exist. The index name follows the existing convention of using idx_ plus the table name and all columns separated by underscores. |
renameTableIfNeeded | {{ renameTableIfNeeded schemaName oldTableName newTableName }} | Renames the table if the new table name does not exist. |
renameColumnIfNeeded | {{ renameColumnIfNeeded schemaName tableName oldVolumnName newColumnName datatype }} | Renames a column if the new column name does not exist. |
doesTableExist | {{if doesTableExist schemaName tableName }} ... {{end}} | Returns true if the table exists. Typically used in a if statement to conditionally include a section of script. Currently the existence of the table is determined before any scripts are executed (limitation of Morph). |
doesColumnExist | {{if doesTableExist schemaName tableName columnName }} ... {{end}} | Returns true if the column exists. Typically used in a if statement to conditionally include a section of script. Currently the existence of the column is determined before any scripts are executed (limitation of Morph). |
Note, table names should not include table prefix or schema name.
Examples
{{ addColumnIfNeeded .schemaName "categories" "type" "varchar(64)" ""}}
{{ addColumnIfNeeded .schemaName "boards_history" "minimum_role" "varchar(36)" "NOT NULL DEFAULT ''"}}
{{ dropColumnIfNeeded .schemaName "blocks_history" "workspace_id" }}
{{ createIndexIfNeeded .schemaName "boards" "team_id, is_template" }}
{{ renameTableIfNeeded .schemaName "blocks" "blocks_history" }}
{{ renameColumnIfNeeded .schemaName "blocks_history" "workspace_id" "channel_id" "varchar(36)" }}
{{if doesTableExist .schemaName "blocks_history" }}
SELECT 'table exists';
{{end}}
{{if not (doesTableExist .schemaName "blocks_history") }}
SELECT 1;
{{end}}
{{if doesColumnExist .schemaName "boards_history" "minimum_role"}}
UPDATE ...
{{end}}