expr.Vars = append(expr.Vars, clause.AndConditions{Exprs: j.On.Exprs})
			}

			j.Expression = expr
		}

		db.Statement.Joins = append(db.Statement.Joins, j)
		sort.Slice(db.Statement.Joins, func(i, j int) bool {
			return db.Statement.Joins[i].Name < db.Statement.Joins[j].Name
		})
		return db
	})
}

func (c chainG[T]) Select(query string, args ...interface{}) ChainInterface[T] {

// If the current relationship is embedded or joined, current query will be ignored.
//
//nolint:cyclop
func preloadEntryPoint(db *gorm.DB, joins []string, relationships *schema.Relationships, preloads map[string][]interface{}, associationsConds []interface{}) error {
	preloadMap := parsePreloadMap(db.Statement.Schema, preloads)

	// avoid random traversal of the map

## Overview

* Full-Featured ORM
* Associations (Has One, Has Many, Belongs To, Many To Many, Polymorphism, Single-table inheritance)
* Hooks (Before/After Create/Save/Update/Delete/Find)
* Eager loading with `Preload`, `Joins`
* Transactions, Nested Transactions, Save Point, RollbackTo to Saved Point
* Context, Prepared Statement Mode, DryRun Mode
* Batch Insert, FindInBatches, Find To Map

	}

	for k, c := range stmt.Clauses {
		newStmt.Clauses[k] = c
	}

	for k, p := range stmt.Preloads {
		newStmt.Preloads[k] = p
	}

	if len(stmt.Joins) > 0 {
		newStmt.Joins = make([]join, len(stmt.Joins))
		copy(newStmt.Joins, stmt.Joins)
	}

	if len(stmt.scopes) > 0 {
		newStmt.scopes = make([]func(*DB) *DB, len(stmt.scopes))
		copy(newStmt.scopes, stmt.scopes)
	}

	l := dns.SplitDomainName(s)
	for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 {
		l[i], l[j] = l[j], l[i]
	}
	return path.Join(append([]string{etcdPathSeparator + prefix + etcdPathSeparator}, l...)...)
}

// dnsJoin joins labels to form a fully qualified domain name. If the last label is
// the root label it is ignored. Not other syntax checks are performed.
func dnsJoin(labels ...string) string {
	if len(labels) == 0 {
		return ""
	}

   */
  public MapJoiner withKeyValueSeparator(String keyValueSeparator) {
    return new MapJoiner(this, keyValueSeparator);
  }

  /**
   * An object that joins map entries in the same manner as {@code Joiner} joins iterables and
   * arrays. Like {@code Joiner}, it is thread-safe and immutable.
   *
   * <p>In addition to operating on {@code Map} instances, {@code MapJoiner} can operate on {@code

		t.Errorf("failed to query users count, got error: %v, count %v", err, count)
	}

	dryDB := DB.Session(&gorm.Session{DryRun: true})
	r := dryDB.Distinct("u.id, u.*").Table("user_speaks as s").Joins("inner join users as u on u.id = s.user_id").Where("s.language_code ='US' or s.language_code ='ES'").Find(&User{})

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

The good news is, once you are on Python 3.10 you won't have to worry about that, as you will be able to simply use `|` to define unions of types:

{* ../../docs_src/python_types/tutorial009c_py310.py hl[1,4] *}

And then you won't have to worry about names like `Optional` and `Union`. 😎

#### Generic types { #generic-types }

/// note

When defining a <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>, include the most specific type first, followed by the less specific type. In the example below, the more specific `PlaneItem` comes before `CarItem` in `Union[PlaneItem, CarItem]`.

为此，请使用 Python 标准类型提示 <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>：

/// note | 笔记

定义 <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a> 类型时，要把详细的类型写在前面，然后是不太详细的类型。下例中，更详细的 `PlaneItem` 位于 `Union[PlaneItem，CarItem]` 中的 `CarItem` 之前。

///