# Go-MySQL-Driver

A MySQL-Driver for Go's [database/sql](http://golang.org/pkg/database/sql) package

![Go-MySQL-Driver logo](https://raw.github.com/wiki/go-sql-driver/mysql/gomysql_m.png "Golang Gopher holding the MySQL Dolphin")

**Latest stable Release:** [Version 1.2 (June 03, 2014)](https://github.com/go-sql-driver/mysql/releases)

[![Build Status](https://travis-ci.org/go-sql-driver/mysql.png?branch=master)](https://travis-ci.org/go-sql-driver/mysql)

---------------------------------------
  * [Features](#features)
  * [Requirements](#requirements)
  * [Installation](#installation)
  * [Usage](#usage)
    * [DSN (Data Source Name)](#dsn-data-source-name)
      * [Password](#password)
      * [Protocol](#protocol)
      * [Address](#address)
      * [Parameters](#parameters)
      * [Examples](#examples)
    * [LOAD DATA LOCAL INFILE support](#load-data-local-infile-support)
    * [time.Time support](#timetime-support)
    * [Unicode support](#unicode-support)
  * [Testing / Development](#testing--development)
  * [License](#license)

---------------------------------------

## Features
  * Lightweight and [fast](https://github.com/go-sql-driver/sql-benchmark "golang MySQL-Driver performance")
  * Native Go implementation. No C-bindings, just pure Go
  * Connections over TCP/IPv4, TCP/IPv6, Unix domain sockets or [custom protocols](http://godoc.org/github.com/go-sql-driver/mysql#DialFunc)
  * Automatic handling of broken connections
  * Automatic Connection Pooling *(by database/sql package)*
  * Supports queries larger than 16MB
  * Full [`sql.RawBytes`](http://golang.org/pkg/database/sql/#RawBytes) support.
  * Intelligent `LONG DATA` handling in prepared statements
  * Secure `LOAD DATA LOCAL INFILE` support with file Whitelisting and `io.Reader` support
  * Optional `time.Time` parsing
  * Optional placeholder interpolation

## Requirements
  * Go 1.2 or higher
  * MySQL (4.1+), MariaDB, Percona Server, Google CloudSQL or Sphinx (2.2.3+)

---------------------------------------

## Installation
Simple install the package to your [$GOPATH](http://code.google.com/p/go-wiki/wiki/GOPATH "GOPATH") with the [go tool](http://golang.org/cmd/go/ "go command") from shell:
```bash
$ go get github.com/go-sql-driver/mysql
```
Make sure [Git is installed](http://git-scm.com/downloads) on your machine and in your system's `PATH`.

## Usage
_Go MySQL Driver_ is an implementation of Go's `database/sql/driver` interface. You only need to import the driver and can use the full [`database/sql`](http://golang.org/pkg/database/sql) API then.

Use `mysql` as `driverName` and a valid [DSN](#dsn-data-source-name)  as `dataSourceName`:
```go
import "database/sql"
import _ "github.com/go-sql-driver/mysql"

db, err := sql.Open("mysql", "user:password@/dbname")
```

[Examples are available in our Wiki](https://github.com/go-sql-driver/mysql/wiki/Examples "Go-MySQL-Driver Examples").


### DSN (Data Source Name)

The Data Source Name has a common format, like e.g. [PEAR DB](http://pear.php.net/manual/en/package.database.db.intro-dsn.php) uses it, but without type-prefix (optional parts marked by squared brackets):
```
[username[:password]@][protocol[(address)]]/dbname[?param1=value1&...&paramN=valueN]
```

A DSN in its fullest form:
```
username:password@protocol(address)/dbname?param=value
```

Except for the databasename, all values are optional. So the minimal DSN is:
```
/dbname
```

If you do not want to preselect a database, leave `dbname` empty:
```
/
```
This has the same effect as an empty DSN string:
```

```

#### Password
Passwords can consist of any character. Escaping is **not** necessary.

#### Protocol
See [net.Dial](http://golang.org/pkg/net/#Dial) for more information which networks are available.
In general you should use an Unix domain socket if available and TCP otherwise for best performance.

#### Address
For TCP and UDP networks, addresses have the form `host:port`.
If `host` is a literal IPv6 address, it must be enclosed in square brackets.
The functions [net.JoinHostPort](http://golang.org/pkg/net/#JoinHostPort) and [net.SplitHostPort](http://golang.org/pkg/net/#SplitHostPort) manipulate addresses in this form.

For Unix domain sockets the address is the absolute path to the MySQL-Server-socket, e.g. `/var/run/mysqld/mysqld.sock` or `/tmp/mysql.sock`.

#### Parameters
*Parameters are case-sensitive!*

Notice that any of `true`, `TRUE`, `True` or `1` is accepted to stand for a true boolean value. Not surprisingly, false can be specified as any of: `false`, `FALSE`, `False` or `0`.

##### `allowAllFiles`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

`allowAllFiles=true` disables the file Whitelist for `LOAD DATA LOCAL INFILE` and allows *all* files.
[*Might be insecure!*](http://dev.mysql.com/doc/refman/5.7/en/load-data-local.html)

##### `allowCleartextPasswords`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

`allowCleartextPasswords=true` allows using the [cleartext client side plugin](http://dev.mysql.com/doc/en/cleartext-authentication-plugin.html) if required by an account, such as one defined with the [PAM authentication plugin](http://dev.mysql.com/doc/en/pam-authentication-plugin.html). Sending passwords in clear text may be a security problem in some configurations. To avoid problems if there is any possibility that the password would be intercepted, clients should connect to MySQL Server using a method that protects the password. Possibilities include [TLS / SSL](#tls), IPsec, or a private network.

##### `allowOldPasswords`

```
Type:           bool
Valid Values:   true, false
Default:        false
```
`allowOldPasswords=true` allows the usage of the insecure old password method. This should be avoided, but is necessary in some cases. See also [the old_passwords wiki page](https://github.com/go-sql-driver/mysql/wiki/old_passwords).

##### `charset`

```
Type:           string
Valid Values:   <name>
Default:        none
```

Sets the charset used for client-server interaction (`"SET NAMES <value>"`). If multiple charsets are set (separated by a comma), the following charset is used if setting the charset failes. This enables for example support for `utf8mb4` ([introduced in MySQL 5.5.3](http://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html)) with fallback to `utf8` for older servers (`charset=utf8mb4,utf8`).

Usage of the `charset` parameter is discouraged because it issues additional queries to the server.
Unless you need the fallback behavior, please use `collation` instead.

##### `collation`

```
Type:           string
Valid Values:   <name>
Default:        utf8_general_ci
```

Sets the collation used for client-server interaction on connection. In contrast to `charset`, `collation` does not issue additional queries. If the specified collation is unavailable on the target server, the connection will fail.

A list of valid charsets for a server is retrievable with `SHOW COLLATION`.

##### `clientFoundRows`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

`clientFoundRows=true` causes an UPDATE to return the number of matching rows instead of the number of rows changed.

##### `columnsWithAlias`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

When `columnsWithAlias` is true, calls to `sql.Rows.Columns()` will return the table alias and the column name separated by a dot. For example:

```
SELECT u.id FROM users as u
```

will return `u.id` instead of just `id` if `columnsWithAlias=true`.

##### `interpolateParams`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

If `interpolateParams` is true, placeholders (`?`) in calls to `db.Query()` and `db.Exec()` are interpolated into a single query string with given parameters. This reduces the number of roundtrips, since the driver has to prepare a statement, execute it with given parameters and close the statement again with `interpolateParams=false`.

*This can not be used together with the multibyte encodings BIG5, CP932, GB2312, GBK or SJIS. These are blacklisted as they may [introduce a SQL injection vulnerability](http://stackoverflow.com/a/12118602/3430118)!*

##### `loc`

```
Type:           string
Valid Values:   <escaped name>
Default:        UTC
```

Sets the location for time.Time values (when using `parseTime=true`). *"Local"* sets the system's location. See [time.LoadLocation](http://golang.org/pkg/time/#LoadLocation) for details.

Note that this sets the location for time.Time values but does not change MySQL's [time_zone setting](https://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html). For that see the [time_zone system variable](#system-variables), which can also be set as a DSN parameter.

Please keep in mind, that param values must be [url.QueryEscape](http://golang.org/pkg/net/url/#QueryEscape)'ed. Alternatively you can manually replace the `/` with `%2F`. For example `US/Pacific` would be `loc=US%2FPacific`.


##### `parseTime`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

`parseTime=true` changes the output type of `DATE` and `DATETIME` values to `time.Time` instead of `[]byte` / `string`


##### `strict`

```
Type:           bool
Valid Values:   true, false
Default:        false
```

`strict=true` enables the strict mode in which MySQL warnings are treated as errors.

By default MySQL also treats notes as warnings. Use [`sql_notes=false`](http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_sql_notes) to ignore notes. See the [examples](#examples) for an DSN example.


##### `timeout`

```
Type:           decimal number
Default:        OS default
```

*Driver* side connection timeout. The value must be a string of decimal numbers, each with optional fraction and a unit suffix ( *"ms"*, *"s"*, *"m"*, *"h"* ), such as *"30s"*, *"0.5m"* or *"1m30s"*. To set a server side timeout, use the parameter [`wait_timeout`](http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_wait_timeout).


##### `tls`

```
Type:           bool / string
Valid Values:   true, false, skip-verify, <name>
Default:        false
```

`tls=true` enables TLS / SSL encrypted connection to the server. Use `skip-verify` if you want to use a self-signed or invalid certificate (server side). Use a custom value registered with [`mysql.RegisterTLSConfig`](http://godoc.org/github.com/go-sql-driver/mysql#RegisterTLSConfig).


##### System Variables

All other parameters are interpreted as system variables:
  * `autocommit`: `"SET autocommit=<value>"`
  * [`time_zone`](https://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html): `"SET time_zone=<value>"`
  * [`tx_isolation`](https://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_tx_isolation): `"SET tx_isolation=<value>"`
  * `param`: `"SET <param>=<value>"`

*The values must be [url.QueryEscape](http://golang.org/pkg/net/url/#QueryEscape)'ed!*

#### Examples
```
user@unix(/path/to/socket)/dbname
```

```
root:pw@unix(/tmp/mysql.sock)/myDatabase?loc=Local
```

```
user:password@tcp(localhost:5555)/dbname?tls=skip-verify&autocommit=true
```

Use the [strict mode](#strict) but ignore notes:
```
user:password@/dbname?strict=true&sql_notes=false
```

TCP via IPv6:
```
user:password@tcp([de:ad:be:ef::ca:fe]:80)/dbname?timeout=90s&collation=utf8mb4_unicode_ci
```

TCP on a remote host, e.g. Amazon RDS:
```
id:password@tcp(your-amazonaws-uri.com:3306)/dbname
```

Google Cloud SQL on App Engine:
```
user@cloudsql(project-id:instance-name)/dbname
```

TCP using default port (3306) on localhost:
```
user:password@tcp/dbname?charset=utf8mb4,utf8&sys_var=esc%40ped
```

Use the default protocol (tcp) and host (localhost:3306):
```
user:password@/dbname
```

No Database preselected:
```
user:password@/
```

### `LOAD DATA LOCAL INFILE` support
For this feature you need direct access to the package. Therefore you must change the import path (no `_`):
```go
import "github.com/go-sql-driver/mysql"
```

Files must be whitelisted by registering them with `mysql.RegisterLocalFile(filepath)` (recommended) or the Whitelist check must be deactivated by using the DSN parameter `allowAllFiles=true` ([*Might be insecure!*](http://dev.mysql.com/doc/refman/5.7/en/load-data-local.html)).

To use a `io.Reader` a handler function must be registered with `mysql.RegisterReaderHandler(name, handler)` which returns a `io.Reader` or `io.ReadCloser`. The Reader is available with the filepath `Reader::<name>` then. Choose different names for different handlers and `DeregisterReaderHandler` when you don't need it anymore.

See the [godoc of Go-MySQL-Driver](http://godoc.org/github.com/go-sql-driver/mysql "golang mysql driver documentation") for details.


### `time.Time` support
The default internal output type of MySQL `DATE` and `DATETIME` values is `[]byte` which allows you to scan the value into a `[]byte`, `string` or `sql.RawBytes` variable in your programm.

However, many want to scan MySQL `DATE` and `DATETIME` values into `time.Time` variables, which is the logical opposite in Go to `DATE` and `DATETIME` in MySQL. You can do that by changing the internal output type from `[]byte` to `time.Time` with the DSN parameter `parseTime=true`. You can set the default [`time.Time` location](http://golang.org/pkg/time/#Location) with the `loc` DSN parameter.

**Caution:** As of Go 1.1, this makes `time.Time` the only variable type you can scan `DATE` and `DATETIME` values into. This breaks for example [`sql.RawBytes` support](https://github.com/go-sql-driver/mysql/wiki/Examples#rawbytes).

Alternatively you can use the [`NullTime`](http://godoc.org/github.com/go-sql-driver/mysql#NullTime) type as the scan destination, which works with both `time.Time` and `string` / `[]byte`.


### Unicode support
Since version 1.1 Go-MySQL-Driver automatically uses the collation `utf8_general_ci` by default.

Other collations / charsets can be set using the [`collation`](#collation) DSN parameter.

Version 1.0 of the driver recommended adding `&charset=utf8` (alias for `SET NAMES utf8`) to the DSN to enable proper UTF-8 support. This is not necessary anymore. The [`collation`](#collation) parameter should be preferred to set another collation / charset than the default.

See http://dev.mysql.com/doc/refman/5.7/en/charset-unicode.html for more details on MySQL's Unicode support.


## Testing / Development
To run the driver tests you may need to adjust the configuration. See the [Testing Wiki-Page](https://github.com/go-sql-driver/mysql/wiki/Testing "Testing") for details.

Go-MySQL-Driver is not feature-complete yet. Your help is very appreciated.
If you want to contribute, you can work on an [open issue](https://github.com/go-sql-driver/mysql/issues?state=open) or review a [pull request](https://github.com/go-sql-driver/mysql/pulls).

See the [Contribution Guidelines](https://github.com/go-sql-driver/mysql/blob/master/CONTRIBUTING.md) for details.

---------------------------------------

## License
Go-MySQL-Driver is licensed under the [Mozilla Public License Version 2.0](https://raw.github.com/go-sql-driver/mysql/master/LICENSE)

Mozilla summarizes the license scope as follows:
> MPL: The copyleft applies to any files containing MPLed code.


That means:
  * You can **use** the **unchanged** source code both in private and commercially
  * When distributing, you **must publish** the source code of any **changed files** licensed under the MPL 2.0 under a) the MPL 2.0 itself or b) a compatible license (e.g. GPL 3.0 or Apache License 2.0)
  * You **needn't publish** the source code of your library as long as the files licensed under the MPL 2.0 are **unchanged**

Please read the [MPL 2.0 FAQ](http://www.mozilla.org/MPL/2.0/FAQ.html) if you have further questions regarding the license.

You can read the full terms here: [LICENSE](https://raw.github.com/go-sql-driver/mysql/master/LICENSE)

![Go Gopher and MySQL Dolphin](https://raw.github.com/wiki/go-sql-driver/mysql/go-mysql-driver_m.jpg "Golang Gopher transporting the MySQL Dolphin in a wheelbarrow")

