genorm

GenORM

SQL Builder to prevent SQL mistakes using the Golang generics

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Feature

By mapping SQL expressions to appropriate golang types using generics, you can discover many SQL mistakes at the time of compilation that are not prevented by traditional Golang ORMs or query builders.

For example:

• Compilation error occurs when using values of different Go types in SQL for = etc. comparisons or updating values in UPDATE statements
• Compile error occurs when using column names of unavailable tables

It also supports many CRUD syntaxes in SQL.

Example

Example 1

String column users.name can be compared to a string value, but comparing it to an int value will result in a compile error.

// correct
userValues, err := genorm.
	Select(orm.User()).
	Where(genorm.EqLit(user.NameExpr, genorm.Wrap("name"))).
	GetAll(db)

// compile error
userValues, err := genorm.
	Select(orm.User()).
	Where(genorm.EqLit(user.NameExpr, genorm.Wrap(1))).
	GetAll(db)

Example 2

You can use an id column from the users table in a SELECT statement that retrieves data from the users table, but using an id column from the messages table will result in a compile error.

// correct
userValues, err := genorm.
	Select(orm.User()).
	Where(genorm.EqLit(user.IDExpr, uuid.New())).
	GetAll(db)

// compile error
userValues, err := genorm.
	Select(orm.User()).
	Where(genorm.EqLit(message.IDExpr, uuid.New())).
	GetAll(db)

Install

GenORM uses the CLI to generate code. The genormpackage is used to invoke queries. For this reason, both the CLI and Package must be install.

CLI

go install github.com/mazrean/genorm/cmd/genorm@v1.0.0

Package

go get -u github.com/mazrean/genorm

Configuration

Example

The users table can join the messages table.

import "github.com/mazrean/genorm"

type User struct {
    // Column Information
    Message genorm.Ref[Message]
}

func (*User) TableName() string {
    return "users"
}

type Message struct {
    // Column Information
}

func (*Message) TableName() string {
    return "messages"
}

Usage

Connecting to a Database

import (
  "database/sql"
  _ "github.com/go-sql-driver/mysql"
)

db, err := sql.Open("mysql", "user:pass@tcp(host:port)/database?parseTime=true&loc=Asia%2FTokyo&charset=utf8mb4")

Insert

// INSERT INTO users (id, name, created_at) VALUES ({{uuid.New()}}, "name1", {{time.Now()}}), ({{uuid.New()}}, "name2", {{time.Now()}})
affectedRows, err := genorm.
    Insert(orm.User()).
    Values(&orm.UserTable{
        ID: uuid.New(),
        Name: genorm.Wrap("name1"),
        CreatedAt: genorm.Wrap(time.Now()),
    }, &orm.UserTable{
        ID: uuid.New(),
        Name: genorm.Wrap("name2"),
        CreatedAt: genorm.Wrap(time.Now()),
    }).
    Do(db)

Select

// SELECT id, name, created_at FROM users
// userValues: []orm.UserTable
userValues, err := genorm.
	Select(orm.User()).
	GetAll(db)

// SELECT id, name, created_at FROM users LIMIT 1
// userValue: orm.UserTable
userValue, err := genorm.
	Select(orm.User()).
	Get(db)

// SELECT id FROM users
// userIDs: []uuid.UUID
userIDs, err := genorm.
	Pluck(orm.User(), user.IDExpr).
	GetAll(db)

// SELECT COUNT(id) AS result FROM users LIMIT 1
// userNum: int64
userNum, err := genorm.
	Pluck(orm.User(), genorm.Count(user.IDExpr, false)).
	Get(db)

Update

// UPDATE users SET name="name"
affectedRows, err = genorm.
    Update(orm.User()).
    Set(
        genorm.AssignLit(user.Name, genorm.Wrap("name")),
    ).
    Do(db)

Delete

// DELETE FROM users
affectedRows, err = genorm.
    Delete(orm.User()).
    Do(db)

Join

Select

// SELECT users.name, messages.content FROM users INNER JOIN messages ON users.id = messages.user_id
// messageUserValues: []orm.MessageUserTable
userID := orm.MessageUserParseExpr(user.ID)
userName := orm.MessageUserParse(user.Name)
messageUserID := orm.MessageUserParseExpr(message.UserID)
messageContent := orm.MessageUserParse(message.Content)
messageUserValues, err := genorm.
	Select(orm.User().
		Message().Join(genorm.Eq(userID, messageUserID))).
	Fields(userName, messageContent).
	GetAll(db)

Update

// UPDATE users INNER JOIN messages ON users.id = messages.id SET content="hello world"
userIDColumn := orm.MessageUserParseExpr(user.ID)
messageUserIDColumn := orm.MessageUserParseExpr(message.UserID)
messageContent := orm.MessageUserParse(message.Content)
affectedRows, err := genorm.
  Update(orm.User().
		Message().Join(genorm.Eq(userID, messageUserID))).
  Set(genorm.AssignLit(messageContent, genorm.Wrap("hello world"))).
  Do(db)

Transaction

tx, err := db.Begin()
if err != nil {
    log.Fatal(err)
}

_, err = genorm.
    Insert(orm.User()).
    Values(&orm.UserTable{
        ID: uuid.New(),
        Name: genorm.Wrap("name1"),
        CreatedAt: genorm.Wrap(time.Now()),
    }, &orm.UserTable{
        ID: uuid.New(),
        Name: genorm.Wrap("name2"),
        CreatedAt: genorm.Wrap(time.Now()),
    }).
    Do(db)
if err != nil {
    _ = tx.Rollback()
    log.Fatal(err)
}

err = tx.Commit()
if err != nil {
    log.Fatal(err)
}

Context

// SELECT id, name, created_at FROM users
// userValues: []orm.UserTable
userValues, err := genorm.
	Select(orm.User()).
	GetAllCtx(context.Background(), db)

// INSERT INTO users (id, name, created_at) VALUES ({{uuid.New()}}, "name", {{time.Now()}})
affectedRows, err := genorm.
    Insert(orm.User()).
    Values(&orm.UserTable{
        ID: uuid.New(),
        Name: genorm.Wrap("name"),
        CreatedAt: genorm.Wrap(time.Now()),
    }).
    DoCtx(context.Background(), db)