for _, v := range []byte(sql) {
			if v == '?' {
				if len(vars) > idx {
					newSQL.WriteString(vars[idx])
					idx++
					continue
				}
			}
			newSQL.WriteByte(v)
		}

		sql = newSQL.String()
	} else {
		sql = numericPlaceholder.ReplaceAllString(sql, "$$$1$$")

		sql = numericPlaceholderRe.ReplaceAllStringFunc(sql, func(v string) string {
			num := v[1 : len(v)-1]

		es                 = ExampleStruct{Name: "test", Val: "test"}
		intVal   intType   = 1
		floatVal floatType = 1.23
	)

	results := []struct {
		SQL           string
		NumericRegexp *regexp.Regexp
		Vars          []interface{}
		Result        string
	}{
		{
			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",

```Python hl_lines="4  14  16-22"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip
    👀 👈 🌐 👉 📟 😁 🇸🇲 🐚.

    `databases` 🚫 🔨 🕳 📥.

## 🗄 & ⚒ 🆙 `databases`

* 🗄 `databases`.
* ✍ `DATABASE_URL`.
* ✍ `database` 🎚.

```Python hl_lines="3  9  12"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip

# 异步 SQL 关系型数据库

**FastAPI** 使用 <a href="https://github.com/encode/databases" class="external-link" target="_blank">`encode/databases`</a> 为连接数据库提供异步支持（`async` 与 `await`）。

`databases` 兼容以下数据库：

* PostgreSQL
* MySQL
* SQLite

本章示例使用 **SQLite**，它使用的是单文件，且 Python 内置集成了 SQLite，因此，可以直接复制并运行本章示例。

生产环境下，则要使用 **PostgreSQL** 等数据库服务器。

!!! tip "提示"

Later, for your production application, you might want to use a database server like **PostgreSQL**.

!!! tip
    You could adopt ideas from the section about SQLAlchemy ORM ([SQL (Relational) Databases](../tutorial/sql-databases.md){.internal-link target=_blank}), like using utility functions to perform operations in the database, independent of your **FastAPI** code.

Harsha Laxman <******@****.***> 1687432812 -0700

```

👈 🛎 🤙 `main.py`, ✋️ ⏸ `main.py` ⚙️ 💽 📁 `sql_app.db`, & 👥 💪 ⚒ 💭 👥 ✍ `test.db` 💯.

👥 🚮 👈 ⏸ 📥, ⏮️ 🆕 📁.

```Python hl_lines="16"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}
```

## 🔗 🔐

🔜 👥 ✍ 🔗 🔐 & 🚮 ⚫️ 🔐 👆 📱.

```Python hl_lines="19-24  27"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}
```

!!! tip

		} else {
			l.Printf(l.traceWarnStr, utils.FileWithLineNum(), slowLog, float64(elapsed.Nanoseconds())/1e6, rows, sql)
		}
	case l.LogLevel == Info:
		sql, rows := fc()
		if rows == -1 {
			l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, "-", sql)
		} else {
			l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
		}
	}
}

				},
			},
			sql: "INNER JOIN `user` USING (`id`)",
		},
	}
	for _, result := range results {
		t.Run(result.name, func(t *testing.T) {
			user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
			stmt := &gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
			result.join.Build(stmt)
			if result.sql != stmt.SQL.String() {

}

// TxCommitter tx committer
type TxCommitter interface {
	Commit() error
	Rollback() error
}

// Tx sql.Tx interface
type Tx interface {
	ConnPool
	TxCommitter
	StmtContext(ctx context.Context, stmt *sql.Stmt) *sql.Stmt
}

// Valuer gorm valuer interface
type Valuer interface {
	GormValue(context.Context, *DB) clause.Expr
}

// GetDBConnector SQL db connector