Gen
Converts a database into gorm structs and RESTful api
Install / Use
/learn @smallnest/GenREADME
gen
The gen tool produces a CRUD (Create, read, update and delete) REST api project template from a given database. The gen tool will connect to the db connection string analyze the database and generate the code based on the flags provided.
By reading details from the database about the column structure, gen generates a go compatible struct type with the required column names, data types, and annotations.
It supports gorm tags and implements some usable methods. Generated data types include support for nullable columns sql.NullX types or guregu null.X types and the expected basic built in go types.
gen is based / inspired by the work of Seth Shelnutt's db2struct, and Db2Struct is based/inspired by the work of ChimeraCoder's gojson package gojson.
CRUD Generation
This is a sample table contained within the ./example/sample.db Sqlite3 database. Using gen will generate the following struct.
CREATE TABLE "albums"
(
[AlbumId] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
[Title] NVARCHAR(160) NOT NULL,
[ArtistId] INTEGER NOT NULL,
FOREIGN KEY ([ArtistId]) REFERENCES "artists" ([ArtistId])
ON DELETE NO ACTION ON UPDATE NO ACTION
)
Transforms into
type Album struct {
//[ 0] AlbumId integer null: false primary: true auto: true col: integer len: -1 default: []
AlbumID int `gorm:"primary_key;AUTO_INCREMENT;column:AlbumId;type:INTEGER;" json:"album_id" db:"AlbumId" protobuf:"int32,0,opt,name=album_id"`
//[ 1] Title nvarchar(160) null: false primary: false auto: false col: nvarchar len: 160 default: []
Title string `gorm:"column:Title;type:NVARCHAR(160);size:160;" json:"title" db:"Title" protobuf:"string,1,opt,name=title"`
//[ 2] ArtistId integer null: false primary: false auto: false col: integer len: -1 default: []
ArtistID int `gorm:"column:ArtistId;type:INTEGER;" json:"artist_id" db:"ArtistId" protobuf:"int32,2,opt,name=artist_id"`
}
Code generation for a complete CRUD rest project is possible with DAO crud functions, http handlers, makefile, sample server are available. Check out some of the code generated samples.
Binary Installation
## install gen tool (should be installed to ~/go/bin, make sure ~/go/bin is in your path.
## go version < 1.17
$ go get -u github.com/smallnest/gen
## go version == 1.17
$ go install github.com/smallnest/gen@latest
## download sample sqlite database
$ wget https://github.com/smallnest/gen/raw/master/example/sample.db
## generate code based on the sqlite database (project will be contained within the ./example dir)
$ gen --sqltype=sqlite3 \
--connstr "./sample.db" \
--database main \
--json \
--gorm \
--guregu \
--rest \
--out ./example \
--module example.com/rest/example \
--mod \
--server \
--makefile \
--json-fmt=snake \
--generate-dao \
--generate-proj \
--overwrite
## build example code (build process will install packr2 if not installed)
$ cd ./example
$ make example
## binary will be located at ./bin/example
## when launching make sure that the SQLite file sample.db is located in the same dir as the binary
$ cp ../../sample.db .
$ ./example
## Open a browser to http://127.0.0.1:8080/swagger/index.html
## Use wget/curl/httpie to fetch via command line
http http://localhost:8080/albums
curl http://localhost:8080/artists
Usage
Usage of gen:
gen [-v] --sqltype=mysql --connstr "user:password@/dbname" --database <databaseName> --module=example.com/example [--json] [--gorm] [--guregu] [--generate-dao] [--generate-proj]
git fetch up
sqltype - sql database type such as [ mysql, mssql, postgres, sqlite, etc. ]
Options:
--sqltype=mysql sql database type such as [ mysql, mssql, postgres, sqlite, etc. ]
-c, --connstr=nil database connection string
-d, --database=nil Database to for connection
-t, --table= Table to build struct from
-x, --exclude= Table(s) to exclude
--templateDir= Template Dir
--fragmentsDir= Code fragments Dir
--save= Save templates to dir
--model=model name to set for model package
--model_naming={{FmtFieldName .}} model naming template to name structs
--field_naming={{FmtFieldName (stringifyFirstChar .) }} field naming template to name structs
--file_naming={{.}} file_naming template to name files
--dao=dao name to set for dao package
--api=api name to set for api package
--grpc=grpc name to set for grpc package
--out=. output dir
--module=example.com/example module path
--overwrite Overwrite existing files (default)
--no-overwrite disable overwriting files
--windows use windows line endings in generated files
--no-color disable color output
--context= context file (json) to populate context with
--mapping= mapping file (json) to map sql types to golang/protobuf etc
--exec= execute script for custom code generation
--json Add json annotations (default)
--no-json Disable json annotations
--json-fmt=snake json name format [snake | camel | lower_camel | none]
--xml Add xml annotations (default)
--no-xml Disable xml annotations
--xml-fmt=snake xml name format [snake | camel | lower_camel | none]
--gorm Add gorm annotations (tags)
--protobuf Add protobuf annotations (tags)
--proto-fmt=snake proto name format [snake | camel | lower_camel | none]
--gogo-proto= location of gogo import
--db Add db annotations (tags)
--guregu Add guregu null types
--copy-templates Copy regeneration templates to project directory
--mod Generate go.mod in output dir
--makefile Generate Makefile in output dir
--server Generate server app output dir
--generate-dao Generate dao functions
--generate-proj Generate project readme and gitignore
--rest Enable generating RESTful api
--run-gofmt run gofmt on output dir
--listen= listen address e.g. :8080
--scheme=http scheme for server url
--host=localhost host for server
--port=8080 port for server
--swagger_version=1.0 swagger version
--swagger_path=/ swagger base path
--swagger_tos= swagger tos url
--swagger_contact_name=Me swagger contact name
--swagger_contact_url=http://me.com/terms.html swagger contact url
--swagger_contact_email=me@me.com swagger contact email
-v, --verbose Enable verbose output
--name_test= perform name test using the --model_naming or --file_naming options
-h, --help Show usage message
--version Show version
Building
The project contains a makefile for easy building and common tasks.
go get- get the relevan
