# Select API Quickstart Guide [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

Traditional retrieval of objects is always as whole entities, i.e GetObject for a 5 GiB object, will always return 5 GiB of data. S3 Select API allows us to retrieve a subset of data by using simple SQL expressions. By using Select API to retrieve only the data needed by the application, drastic performance improvements can be achieved.

		t.Fatalf("invalid sql generated, got %v", sql)
	}

	sql = DB.Session(&gorm.Session{DryRun: true}).Table("user u").Select("name").Find(&User{}).Statement.SQL.String()
	if !regexp.MustCompile(`SELECT .name. FROM user u WHERE .u.\..deleted_at. IS NULL`).MatchString(sql) {
		t.Errorf("Table with escape character, got %v", sql)
	}

index*       (string)             Elasticsearch index to store/update events, index is auto-created
format*      (namespace*|access)  'namespace' reflects current bucket/object list and 'access' reflects a journal of object operations, defaults to 'namespace'
queue_dir    (path)               staging dir for undelivered messages e.g. '/home/events'

		t.Fatalf("Joins expected %s, got %+v", u.Name, result)
	}

	// Raw Subquery JOIN + WHERE + Select
	result, err = db.Joins(clause.LeftJoin.AssociationFrom("Company", gorm.G[Company](DB).Select("Name")).As("t"),
		func(db gorm.JoinBuilder, joinTable clause.Table, curTable clause.Table) error {
			if joinTable.Name != "t" {

		Name string
		Age  int
	}

	var res result
	DB.Table("users").Select("id, name, age").Where("id = ?", user3.ID).Scan(&res)
	if res.ID != user3.ID || res.Name != user3.Name || res.Age != int(user3.Age) {
		t.Fatalf("Scan into struct should work, got %#v, should %#v", res, user3)
	}

	var resPointer *result
	if err := DB.Table("users").Select("id, name, age").Where("id = ?", user3.ID).Scan(&resPointer).Error; err != nil {

* "Add configuration...".
* Select "Python"
* Run the debugger with the option "`Python: Current File (Integrated Terminal)`".

It will then start the server with your **FastAPI** code, stop at your breakpoints, etc.

Here's how it might look:

<img src="/img/tutorial/debugging/image01.png">

---

If you use Pycharm, you can:

* Open the "Run" menu.
* Select the option "Debug...".

	var result5 NamedUser
	if err := DB.Raw("SELECT * FROM named_users WHERE (name1 = @name AND name3 = @name) AND name2 = @name2", map[string]interface{}{"name": "jinzhu-new", "name2": "jinzhu-new2"}).Find(&result5).Error; err != nil {
		t.Errorf("failed to update with named arg")
	}

	AssertEqual(t, result5, namedUser)

	var result6 NamedUser
	if err := DB.Raw(`SELECT * FROM named_users WHERE (name1 = @name

func TestFrom(t *testing.T) {
	results := []struct {
		Clauses []clause.Interface
		Result  string
		Vars    []interface{}
	}{
		{
			[]clause.Interface{clause.Select{}, clause.From{}},
			"SELECT * FROM `users`", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{
					Tables: []clause.Table{{Name: "users"}},
					Joins: []clause.Join{
						{
							Type:  clause.InnerJoin,

	user := User{Name: "jinzhu"}

	DB.Create(&user)

	subQuery := DB.Table("users").Where("name=?", user.Name).Select("id")

	result := DB.Session(&gorm.Session{DryRun: true}).Model(&Pet{}).Create([]map[string]interface{}{
		{
			"name":    "cat",
			"user_id": gorm.Expr("(?)", DB.Table("(?) as tmp", subQuery).Select("@uid:=id")),
		},
		{
			"name":    "dog",
			"user_id": gorm.Expr("@uid"),
		},
	})

$(function() {
  $('input[type="text"],select,textarea', ".login-box,section.content")
    .first()
    .focus();
  $(".form-group .has-error")
    .first()
    .next("input,select,textarea")
    .focus();

  $("section.content input").keypress(function(e) {
    var $submitButton;
    if (e.which === 13) {
      $submitButton = $("input#submit, button#submit");
      if ($submitButton.length > 0) {
        $submitButton[0].submit();
      }