Table.Columns/Constraints/Indexes/Relationships are Go maps, and every writer, reader, diff, inspector, and merge code path that iterated them directly was subject to Go's randomized map order, so identical input could produce different output (or a different in-report violation/diff order) on every run. Most visibly this showed up as bun/gorm `unique:` struct tags changing order across consecutive `make models` runs with no source change. Fixed by sorting map iteration (by Sequence then Name, or alphabetically for string-keyed maps) everywhere the order affects generated output or first-match tie-break logic, across the bun, gorm, sqlite, dbml, drawdb, pgsql, prisma, graphql, typeorm, drizzle, and dctx writers; the dctx, prisma, and typeorm readers; the shared models.GetPrimaryKey/ GetForeignKeys helpers; pkg/diff, pkg/inspector, and pkg/merge; and the TUI column/relationship pickers in pkg/ui.
DBML Writer
Generates Database Markup Language (DBML) files from database schema information.
Overview
The DBML Writer converts RelSpec's internal database model representation into DBML syntax, suitable for use with dbdiagram.io and other DBML-compatible tools.
Features
- Generates DBML syntax
- Creates table definitions with columns
- Defines relationships
- Includes indexes
- Adds notes and documentation
- Supports enums
Usage
Basic Example
package main
import (
"git.warky.dev/wdevs/relspecgo/pkg/models"
"git.warky.dev/wdevs/relspecgo/pkg/writers"
"git.warky.dev/wdevs/relspecgo/pkg/writers/dbml"
)
func main() {
options := &writers.WriterOptions{
OutputPath: "schema.dbml",
}
writer := dbml.NewWriter(options)
err := writer.WriteDatabase(db)
if err != nil {
panic(err)
}
}
CLI Examples
# Generate DBML from PostgreSQL database
relspec --input pgsql \
--conn "postgres://localhost/mydb" \
--output dbml \
--out-file schema.dbml
# Convert GORM models to DBML
relspec --input gorm --in-file models.go --output dbml --out-file database.dbml
# Convert JSON to DBML for visualization
relspec --input json --in-file schema.json --output dbml --out-file diagram.dbml
Generated DBML Example
Project MyDatabase {
database_type: 'PostgreSQL'
}
Table users {
id bigserial [pk, increment]
username varchar(50) [not null, unique]
email varchar(100) [not null]
bio text [null]
created_at timestamp [not null, default: `now()`]
Note: 'Users table'
indexes {
email [name: 'idx_users_email']
}
}
Table posts {
id bigserial [pk, increment]
user_id bigint [not null]
title varchar(200) [not null]
content text [null]
created_at timestamp [default: `now()`]
indexes {
user_id [name: 'idx_posts_user_id']
(user_id, created_at) [name: 'idx_posts_user_created']
}
}
Ref: posts.user_id > users.id [delete: cascade, update: no action]
DBML Features
Table Definitions
Table table_name {
column_name type [attributes]
}
Column Attributes
pk- Primary keyincrement- Auto-incrementnot null- NOT NULL constraintnull- Nullable (explicit)unique- Unique constraintdefault: value- Default valuenote: 'text'- Column note
Relationships
Ref: table1.column > table2.column
Ref: table1.column < table2.column
Ref: table1.column - table2.column
Relationship types:
>- Many-to-one<- One-to-many-- One-to-one
Relationship actions:
Ref: posts.user_id > users.id [delete: cascade, update: restrict]
Indexes
indexes {
column_name
(column1, column2) [name: 'idx_name', unique]
}
Type Mapping
| SQL Type | DBML Type |
|---|---|
| bigint | bigint |
| integer | int |
| varchar(n) | varchar(n) |
| text | text |
| boolean | boolean |
| timestamp | timestamp |
| date | date |
| json | json |
| uuid | uuid |
Notes
- DBML is designed for database visualization
- Can be imported into dbdiagram.io
- Human-readable format
- Schema names can be included in table names
- Comments and notes are preserved
- Ideal for documentation and sharing designs