go-sql-driver/mysql
CategoryDatabase Drivers
SubcategoryRelational Database Drivers
Stars15,271
MySQL driver for Go
About go-sql-driver/mysql
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# Go-MySQL-Driver
[](https://deepwiki.com/go-sql-driver/mysql)
A MySQL-Driver for Go's [database/sql](https://golang.org/pkg/database/sql/) package
---------------------------------------
* [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)
* [Verifying Server](#verifying-server)
* [OpenID Connect authentication](#openid-connect-authentication)
* [Connection pool and timeouts](#connection-pool-and-timeouts)
* [context.Context Support](#contextcontext-support)
* [ColumnType Support](#columntype-support)
* [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](https://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`](https://golang.org/pkg/database/sql/#RawBytes) support.
* Intelligent `LONG DATA` handling in prepared statements
* Secure `LOAD DATA LOCAL INFILE` support with file allowlisting and `io.Reader` support
* Optional `time.Time` parsing
* Optional placeholder interpolation
* Supports zlib compression and optional zstd compression.
## Requirements
* Go 1.25 or higher. We aim to support the 3 latest versions of Go.
* MySQL (8.0+) and MariaDB (10.11+) are supported by maintainers.
* [TiDB](https://github.com/pingcap/tidb) is supported by PingCAP.
* Do not ask questions about TiDB in our issue tracker or forum.
* [Document](https://docs.pingcap.com/tidb/v6.1/dev-guide-sample-application-golang)
* [Forum](https://ask.pingcap.com/)
* go-mysql would work with Percona Server, Google CloudSQL or Sphinx (2.2.3+).
* Maintainers won't support them. Do not expect issues are investigated and resolved by maintainers.
* Investigate issues yourself and please send a pull request to fix it.
---------------------------------------
## Installation
Simple install the package to your [$GOPATH](https://github.com/golang/go/wiki/GOPATH "GOPATH") with the [go tool](https://golang.org/cmd/go/ "go command") from shell:
```bash
go get -u github.com/go-sql-driver/mysql
```
Make sure [Git is installed](https://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`](https://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"
"time"
_ "github.com/go-sql-driver/mysql"
)
// ...
db, err := sql.Open("mysql", "user:password@/dbname")
if err != nil {
panic(err)
}
// See "Important settings" section.
db.SetConnMaxLifetime(time.Minute * 3)
db.SetMaxOpenConns(10)
db.SetMaxIdleConns(10)
```
[Examples are available in our Wiki](https://github.com/go-sql-driver/mysql/wiki/Examples "Go-MySQL-Driver Examples").
### Important settings
`db.SetConnMaxLifetime()` is required to ensure connections are closed by the driver safely before connection is closed by MySQL server, OS, or other middlewares. Since some middlewares close idle connections by 5 minutes, we recommend timeout shorter than 5 minutes. This setting helps load balancing and changing system variables too.
`db.SetMaxOpenConns()` is highly recommended to limit the number of connection used by the application. There is no recommended limit number because it depends on application and MySQL server.
`db.SetMaxIdleConns()` is recommended to be set same to `db.SetMaxOpenConns()`. When it is smaller than `SetMaxOpenConns()`, connections can be opened and closed much more frequently than you expect. Idle connections can be closed by the `db.SetConnMaxLifetime()`. If you want to close idle connections more rapidly, you can use `db.SetConnMaxIdleTime()` since Go 1.15.
### 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&...¶mN=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:
```
```
`dbname` is escaped by [PathEscape()](https://pkg.go.dev/net/url#PathEscape) since v1.8.0. If your database name is `dbname/withslash`, it becomes:
```
/dbname%2Fwithslash
```
Alternatively, [Config.FormatDSN](https://godoc.org/github.com/go-sql-driver/mysql#Config.FormatDSN) can be used to create a DSN string by filling a struct.
#### Password
Passwords can consist of any character. Escaping is **not** necessary.
#### Protocol
See [net.Dial](https://golang.org/pkg/net/#Dial) for more information which networks are available.
In general you should use a Unix domain socket if available and TCP otherwise for best performance.
#### Address
For TCP and UDP networks, addresses have the form `host[:port]`.
If `port` is omitted, the default port will be used.
If `host` is a literal IPv6 address, it must be enclosed in square brackets.
The functions [net.JoinHostPort](https://golang.org/pkg/net/#JoinHostPort) and [net.SplitHostPort](https://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 allowlist for `LOAD DATA LOCAL INFILE` and allows *all* files.
[*Might be insecure!*](https://dev.mysql.com/doc/refman/8.0/en/load-data.html#load-data-local)
##### `allowCleartextPasswords`
```
Type: bool
Valid Values: true, false
Default: false
```
`allowCleartextPasswords=true` allows using the [cleartext client side plugin](https://dev.mysql.com/doc/en/cleartext-pluggable-authentication.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.
##### `allowFallbackToPlaintext`
```
Type: bool
Valid Values: true, false
Default: false
```
`allowFallbackToPlaintext=true` acts like a `--ssl-mode=PREFERRED` MySQL client as described in [Command Options for Connecting to the Server](https://dev.mysql.com/doc/refman/5.7/en/connection-options.html#option_general_ssl-mode)
##### `allowNativePasswords`
```
Type: bool
Valid Values: true, false
Default: true
```
`allowNativePasswords=false` disallows the usage of MySQL native password method.
##### `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 fails. 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`).
See also [Unicode Support](#unicode-support).
##### `checkConnLiveness`
```
Type: bool
Valid Values: true, false
Default: true
```
On supported platforms connections retrieved from the connection pool are checked for liveness before using them. If the check fails, the respective connection is marked as bad and the query retried with another connection.
`checkConnLiveness=false` disables this liveness check of connections.
##### `collation`
```
Type: string
Valid Values: <name>
Default: utf8mb4_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`.
The default collation (`utf8mb4_general_ci`) is supported from MySQL 5.5. You should use an older collation (e.g. `utf8_general_ci`) for older MySQL.
Collations for charset "ucs2", "utf16", "utf16le", and "utf32" can not be used ([ref](https://dev.mysql.com/doc/refman/5.7/en/charset-connection.html#charset-connection-impermissible-client-charset)).
See also [Unicode Support](#unicode-support).
##### `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`.
##### `compress`
```
Type: bool
Valid Values: true, false
Default: false
```
Toggles compression. false by default. Connections use zlib unless the optional
`github.com/go-sql-driver/mysql/zstd` package is imported:
```go
import _ "github.com/go-sql-driver/mysql/zstd"
```
This import also registers the MySQL driver. With `compress=true` (or
`EnableCompression(true)`), connections automatically prefer zstd when the server
supports it and fall back to zlib otherwise.
Applications that do not import `mysql/zstd` do not compile or link
`github.com/klauspost/compress`. The optional package's dependency is listed in the
module's `go.mod`.
##### `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 rejected 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](https://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](https://golang.org/pkg/net/url/#QueryEscape)'ed. Alternatively you can manually replace the `/` with `%2F`. For example `US/Pacific` would be `loc=US%2FPacific`.
##### `timeTruncate`
```
Type: duration
Default: 0
```
[Truncate time values](https://pkg.go.dev/time#Duration.Truncate) in query arguments to the specified duration. The value must be a decimal number with a unit suffix (*"ns"*, *"us"*, *"ms"*, etc...), such as "1us", "1ms", or "10ns".
> [!NOTE]
> `time.Time` arguments are sent with up to nanosecond precision, so a value from `time.Now()` usually has more fractional-second digits than a `DATETIME(N)` or `TIMESTAMP(N)` column stores. On MariaDB, comparing such a value against an indexed column can prevent an index range scan, turning it into a full index scan. Truncating to the column's precision (`1us` for `DATETIME(6)`) avoids this. Only arguments sent to the server are truncated; values read from the server are not affected.
##### `tinyInt1IsBool`
```
Type: bool
Valid Values: true, false
Default: true
```
When `tinyInt1IsBool=true`, signed `TINYINT(1)` columns are treated as boolean values. Zero is returned as `false`, and non-zero values are returned as `true`. Their database type name is reported as `BOOLEAN`, and their scan type is `bool` for non-nullable columns or `sql.NullBool` for nullable columns.
Unsigned and `ZEROFILL` columns are not converted. Set `tinyInt1IsBool=false` to preserve the numeric `TINYINT` behavior.
##### `maxAllowedPacket`
```
Type: decimal number
Default: 64*1024*1024
```
Max packet size allowed in bytes. The default value is 64 MiB and should be adjusted to match the server settings. `maxAllowedPacket=0` can be used to automatically fetch the `max_allowed_packet` variable from server *on every connection*.
##### `multiStatements`
```
Type: bool
Valid Values: true, false
Default: false
```
Allow multiple statements in one query. This can be used to bach multiple queries. Use [Rows.NextResultSet()](https://pkg.go.dev/database/sql#Rows.NextResultSet) to get result of the second and subsequent queries.
When `multiStatements` is used, `?` parameters must only be used in the first statement. [interpolateParams](#interpolateparams) can be used to avoid this limitation unless prepared statement is used explicitly.
It's possible to access the last inserted ID and number of affected rows for multiple statements by using `sql.Conn.Raw()` and the `mysql.Result`. For example:
```go
conn, _ := db.Conn(ctx)
conn.Raw(func(conn any) error {
ex := conn.(driver.Execer)
res, err := ex.Exec(`
UPDATE point SET x = 1 WHERE y = 2;
UPDATE point SET x = 2 WHERE y = 3;
`, nil)
// Both slices have 2 elements.
log.Print(res.(mysql.Result).AllRowsAffected())
log.Print(res.(mysql.Result).AllLastInsertIds())
})
```
##### `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`
The date or datetime like `0000-00-00 00:00:00` is converted into zero value of `time.Time`.
##### `readTimeout`
```
Type: duration
Default: 0
```
I/O read timeout. The value must be a decimal number with a unit suffix (*"ms"*, *"s"*, *"m"*, *"h"*), such as *"30s"*, *"0.5m"* or *"1m30s"*.
##### `rejectReadOnly`
```
Type: bool
Valid Values: true, false
Default: false
```
`rejectReadOnly=true` causes the driver to reject read-only connections. This
is for a possible race condition during an automatic failover, where the mysql
client gets connected to a read-only replica after the failover.
Note that this should be a fairly rare case, as an automatic failover normally
happens when the primary is down, and the race condition shouldn't happen
unless it comes back up online as soon as the failover is kicked off. On the
other hand, when this happens, a MySQL application can get stuck on a
read-only connection until restarted. It is however fairly easy to reproduce,
for example, using a manual failover on AWS Aurora's MySQL-compatible cluster.
If you are not relying on read-only transactions to reject writes that aren't
supposed to happen, setting this on some MySQL providers (such as AWS Aurora)
is safer for failovers.
Note that ERROR 1290 can be returned for a `read-only` server and this option will
cause a retry for that error. However the same error number is used for some
other cases. You should ensure your application will never cause an ERROR 1290
except for `read-only` mode when enabling this option.
##### `serverPubKey`
```
Type: string
Valid Values: <name>
Default: none
```
Server public keys can be registered with [`mysql.RegisterServerPubKey`](https://godoc.org/github.com/go-sql-driver/mysql#RegisterServerPubKey), which can then be used by the assigned name in the DSN.
Public keys are used to transmit encrypted data, e.g. for authentication.
If the server's public key is known, it should be set manually to avoid expensive and potentially insecure transmissions of the public key from the server to the client each time it is required.
##### `timeout`
```
Type: duration
Default: OS default
```
Timeout for establishing connections, aka dial timeout. The value must be a decimal number with a unit suffix (*"ms"*, *"s"*, *"m"*, *"h"*), such as *"30s"*, *"0.5m"* or *"1m30s"*.
##### `tls`
```
Type: bool / string
Valid Values: true, false, skip-verify, preferred, <name>
Default: false
```
Frequently Asked Questions
What is go-sql-driver/mysql?
go-sql-driver/mysql is a Database Drivers library for the Go programming language. MySQL driver for Go
How many GitHub stars does go-sql-driver/mysql have?
go-sql-driver/mysql has 15,271 GitHub stars in the directory's latest synchronization.
How do I install go-sql-driver/mysql?
Install go-sql-driver/mysql with the Go module system using `go get go-sql-driver/mysql`. Check the repository for the current installation instructions.
What category does go-sql-driver/mysql belong to?
go-sql-driver/mysql is listed under Database Drivers, specifically Relational Database Drivers.