DBML parser for Go

DBML-go is a Go parser for DBML syntax.

Installation

Go get

go get github.com/vanhtuan0409/dbml-go/...

Quick start

package main

import (
	"fmt"
	"os"

	"github.com/vanhtuan0409/dbml-go/parser"
	"github.com/vanhtuan0409/dbml-go/scanner"
)

func main() {
	f, _ := os.Open("test.dbml")
	s := scanner.NewScanner(f)
	parser := parser.NewParser(s)
	dbml, err := parser.Parse()
	if err != nil {
		fmt.Printf("%s\n", err)
		os.Exit(1)
	}

	// process dbml here
}

Go model generate

go get github.com/vanhtuan0409/dbml-go/cmd/dbml-go-gen-model

Usage:
  dbml-gen-go-model [flags]

Flags:
  -E, --exclude string          regex for exclude "from" files. Only applied if "from" is a directory
  -t, --fieldtags stringArray   go field tags (default [db,json,mapstructure])
  -f, --from string             source of dbml, can be https://dbdiagram.io/... | fire_name.dbml (default "database.dbml")
      --gen-table-name          should generate "TableName" function
  -h, --help                    help for dbml-gen-go-model
  -o, --out string              output folder (default "model")
  -p, --package string          single for multiple files (default "model")
      --parse-annotation        Should parse annotations in "note" text
      --recursive               recursive search directory. Only applied if "from" is a directory

Example:

input:

// database.dbml
Table users as U {
  id int [pk, unique, increment] // auto-increment
  full_name varchar [not null, unique, default: 1]
  created_at timestamp
  country_code int
  Note: 'This is simple note'
}

Run:

mkdir -p model
dbml-gen-go-model -f database.dbml -o model -p model

output: model/users.table.go

// Code generated by dbml-gen-go-model. DO NOT EDIT.
// Supported by vanhtuan0409@2020
package model

// User is generated type for table 'users'
type User struct {
	ID          int    `db:"id" json:"id" mapstructure:"id"`
	FullName    string `db:"full_name" json:"full_name" mapstructure:"full_name"`
	CreatedAt   int    `db:"created_at" json:"created_at" mapstructure:"created_at"`
	CountryCode int    `db:"country_code" json:"country_code" mapstructure:"country_code"`
}

// table 'users' columns list struct
type __tbl_users_columns struct {
	ID          string
	FullName    string
	CreatedAt   string
	CountryCode string
}

// table 'users' metadata struct
type __tbl_users struct {
	Name    string
	Columns __tbl_users_columns
}

// table 'users' metadata info
var _tbl_users = __tbl_users{
	Columns: __tbl_users_columns{
		CountryCode: "country_code",
		CreatedAt:   "created_at",
		FullName:    "full_name",
		ID:          "id",
	},
	Name: "users",
}

// GetColumns return list columns name for table 'users'
func (*__tbl_users) GetColumns() []string {
	return []string{"id", "full_name", "created_at", "country_code"}
}

// T return metadata info for table 'users'
func (*User) T() *__tbl_users {
	return &_tbl_users
}

DBML annotations

DBML-go extends DBML with Annotation concepts. Annotation is the markup at the very beginning of note and only available on Project, Table and Column. Annotation serve the purpose of provide extra information for code generation.

Syntax of annotation as follow: @{key}({value}). Multiple annotations are separated by comma ,. Examples:

• Single annotation: [note: '@gotype(github.com/foo/bar:CustomValue)']
• Multiple annotation: [note: '@gotype(time:Time), @gopointer(true)']
• Mixed with data: [note: '@gopointer(true) My example note']

Only these following annotation are understood by DBML-go

gotype

Annotate on DBML Column. The annotated column will be generated with that Go Struct.

For example: you have a custom struct github.com/foo/bar:CustomValue which implement sql.Scanner and driver.Valuer. This struct will be serialized into DB as varchar. Then you can have as follow:

// database.dbml
Table users as U {
  my_custom_value varchar [note:'@gotype(github.com/foo/bar:CustomValue)']
}

Then the generated struct is:

package model

// User is generated type for table 'users'
type User struct {
  // @gotype(github.com/foo/bar:CustomValue)
  MyCustomValue bar.CustomValue `gorm:"my_custom_value"`
}

gopointer

Annotate on DBML Column. The annotated column will be generated as pointer of the target struct. Annotation value must be "true"

For example:

// database.dbml
Table users as U {
  my_custom_value varchar [note:'@gopointer(true)']
}

Then the generated struct is:

package model

// User is generated type for table 'users'
type User struct {
  // @gopointer(true)
  MyCustomValue *string `gorm:"my_custom_value"`
}