Squalor is a library of SQL utilities for marshalling and unmarshalling of model structs into table rows and programmatic construction of SQL statements. It is a combination of the functionality in ORM-like libraries such as gorp, SQL utility libraries such as sqlx and SQL construction libraries such as sqlbuilder. Squalor helps ensure your programs don't contains SQL injection (SQLi) bugs.

package main

import (
  "database/sql"
  "fmt"

  _ "github.com/go-sql-driver/mysql"
  "github.com/square/squalor"
)

type Book struct {
  ID   int  `db:"id"`
  Title string `db:"title"`
  Author int `db:"author"`
}

func main()  {
  _db, err := sql.Open("mysql", "root@/test_db")
  panicOnError(err)

  // Create a test database
  _, err = _db.Exec("DROP TABLE IF EXISTS books")
  panicOnError(err)
  _, err = _db.Exec("CREATE TABLE books (id int primary key, title varchar(255), author int)")
  panicOnError(err)

  // Bind the Go struct with the database
  db := squalor.NewDB(_db)
  book := &Book{}
  books, err := db.BindModel("books", book)
  panicOnError(err)

  // Sample inserts
  book = &Book{ID: 1, Title: "Defender Of Greatness", Author: 1234}
  err = db.Insert(book)
  panicOnError(err)

  book = &Book{ID: 2, Title: "Destiny Of Silver", Author: 1234}
  err = db.Insert(book)
  panicOnError(err)

  // Sample query by primary key
  err = db.Get(book, 2)
  panicOnError(err)
  fmt.Printf("%v\n", book)

  // More complicated query
  q := books.Select(books.All()).Where(books.C("author").Eq(1234))
  var results []Book
  err = db.Select(&results, q)
  panicOnError(err)
  fmt.Printf("results: %v\n", results)
}

func panicOnError(err error) {
  if err != nil {
    panic(err)
  }
}

Full godoc output from the latest code in master is available here:

http://godoc.org/github.com/square/squalor

While squalor uses the database/sql package, the SQL it utilizes is MySQL specific (e.g. REPLACE, INSERT ON DUPLICATE KEY UPDATE, etc).

Squalor started as an experiment to provide programmatic construction of SQL statements to protected against SQL injection attacks that can sneak into code when using printf-style construction. Such SQL injection attacks can occur even in the presence of placeholders if the programmer accidentally uses user data either without a placeholder or in a portion of the SQL statement where a placeholder cannot be used (e.g. for a column name).

The programmatic SQL construction experiment then combined with an experiment to optimize batch operations in gorp. The internal changes to gorp were significant enough to necessitate a fork to get this done. Some of the API was adjusted via learnings from sqlx (e.g. the removal of TypeConverter).

Squalor emerged from these experiments to satisfy internal short term needs. It is being released in the hopes that others will learn from it and find it useful just as we've learned from and utilized gorp, sqlx and sqlbuilder.

Copyright 2014 Square, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.