MySQL .NET Connection String Options

The simplest MySQL connection string for C# is:

new MySqlConnection("Server=YOURSERVER;User ID=YOURUSERID;Password=YOURPASSWORD")

For all the other options, see the tables below. MySqlConnector supports most of Oracle’s Connector/NET connection options .

There are also several unique options that are supported only by MySqlConnector, a replacement for MySql.Data that fixes bugs , adds new features, and improves database access performance. Install it now .

Connection Options

These options specify how to connect and authenticate to a MySQL database.

Name	Default	Description
Server, Host, Data Source, DataSource, Address, Addr, Network Address	localhost	The host name or network address of the MySQL Server to which to connect. Multiple hosts can be specified in a comma-delimited list. On Unix-like systems, this can be a fully qualified path to a MySQL socket file, which will cause a Unix socket to be used instead of a TCP/IP socket. Only a single socket name can be specified.
Port	3306	The TCP port on which MySQL Server is listening for connections.
User ID, UserID, Username, Uid, User name, User		The MySQL user ID.
Password, pwd		The password for the MySQL user. For systems that use frequently-updated authentication tokens (such as Amazon Aurora RDS with IAM Authentication), leave this value empty, and set `MySqlConnection.ProvidePasswordCallback` to a delegate that will provide the password (or authentication token) on demand before calling `MySqlConnection.Open` . This retains the benefits of connection pooling.
Database, Initial Catalog		(Optional) The case-sensitive name of the initial database to use. This may be required if the MySQL user account only has access rights to particular databases on the server.
Load Balance, LoadBalance	RoundRobin	The load-balancing strategy to use when `Host` contains multiple, comma-delimited, host names. The options include: RoundRobin Each new connection opened for this connection pool uses the next host name (sequentially with wraparound). Requires `Pooling=True` . This is the default if `Pooling=True` . FailOver Each new connection tries to connect to the first host; subsequent hosts are used only if connecting to the first one fails. This is the default if `Pooling=False` . Random Servers are tried in a random order. LeastConnections Servers are tried in ascending order of number of currently-open connections in this connection pool. Requires `Pooling=True` .
Connection Protocol, ConnectionProtocol, Protocol	Socket	How to connect to the MySQL Server. This option has the following values: Socket (default): Use TCP/IP sockets. Unix : Use a Unix socket. Pipe : Use a Windows named pipe.
Pipe Name, Pipe, PipeName	MYSQL	The name of the Windows named pipe to use to connect to the server. You must also set `ConnectionProtocol=pipe` to used named pipes.

Connecting to Multiple Servers

The Server option supports multiple comma-delimited host names. The LoadBalance option controls how load is distributed across backend servers. Some of these options ( RoundRobin , LeastConnections ) only take effect if Pooling=True ; however Random and FailOver can be used with Pooling=False .

RoundRobin (default), Random : A total of MaximumPoolSize connections will be opened, but they may be unevenly distributed across back ends.
LeastConnections : A total of MaximumPoolSize connections will be opened, and they will be evenly distributed across back ends. The active connections will be selected from the pool in least-recently-used order, which does not ensure even load across the back ends. You should set MaximumPoolSize to the number of servers multiplied by the desired maximum number of open connections per backend server.
Failover : All connections will initially be made to the first server in the list. You should set MaximumPoolSize to the maximum number of open connections you want per server.

SSL/TLS Options

These are the options that need to be used in order to configure a connection to use SSL/TLS.

Name	Default	Description
SSL Mode, SslMode	Preferred	This option has the following values: Preferred - (this is the default). Use SSL if the server supports it. None - Do not use SSL. Required - Always use SSL. Deny connection if server does not support SSL. Does not validate CA or hostname. VerifyCA - Always use SSL. Validates the CA but tolerates hostname mismatch. VerifyFull - Always use SSL. Validates CA and hostname.
Certificate File, CertificateFile		The path to a certificate file in PKCS #12 (.pfx) format containing a bundled Certificate and Private Key used for mutual authentication. To create a PKCS #12 bundle from a PEM encoded Certificate and Key, use `openssl pkcs12 -in cert.pem -inkey key.pem -export -out bundle.pfx` . This option should not be specified if `SslCert` and `SslKey` are used. If the certificate can't be loaded from a file path, leave this value empty and set `MySqlConnection.ProvideClientCertificatesCallback` before calling `MySqlConnection.Open` . The property should be set to an async delegate that will populate a `X509CertificateCollection` with the client certificate(s) needed to connect.
Certificate Password, CertificatePassword		The password for the certificate specified using the `CertificateFile` option. Not required if the certificate file is not password protected.
Certificate Store Location, CertificateStoreLocation	None	Specifies whether the connection should be encrypted with a certificate from the Certificate Store on the machine. The default value of `None` means the certificate store is not used; a value of `CurrentUser` or `LocalMachine` uses the specified store.
Certificate Thumbprint, CertificateThumbprint		Specifies which certificate should be used from the certificate store specified in the setting above. This option must be used to indicate which certificate in the store should be used for authentication.
SSL Cert, SslCert, Ssl-Cert		The path to the client’s SSL certificate file in PEM format. `SslKey` must also be specified, and `CertificateFile` should not be. This option is not supported on `netstandard2.0` .
SSL Key, SslKey, Ssl-Key		The path to the client’s SSL private key in PEM format. `SslCert` must also be specified, and `CertificateFile` should not be.
SSL CA, CA Certificate File, CACertificateFile, SslCa, Ssl-Ca		The path to a CA certificate file in a PEM Encoded (.pem) format. This should be used with `SslMode=VerifyCA` or `SslMode=VerifyFull` to enable verification of a CA certificate that is not trusted by the operating system’s certificate store. To provide a custom callback to validate the remote certificate, leave this option empty and set `SslMode` to `Required` (or `Preferred` ), then set `MySqlConnection.RemoteCertificateValidationCallback` before calling `MySqlConnection.Open` . The property should be set to a delegate that will validate the remote certificate, as per the documentation .
TLS Version, TlsVersion, Tls-Version		The TLS versions which may be used during TLS negotiation. The default value of `null` allows the OS to determine the TLS version to use (see documentation ); this is the recommended setting. Otherwise, to restrict the versions that can be used, specify a comma-delimited list of versions taken from the following: `TLS 1.0` , `TLS 1.1.` , `TLS 1.2` , `TLS 1.3` . (This option allows each version to be specified in a few different formats: `Tls12` , `Tlsv1.2` , `TLS 1.2` , `Tls v1.2` ; they are treated equivalently.)
TLS Cipher Suites,TlsCipherSuites		The TLS cipher suites which may be used during TLS negotiation. The default value (the empty string) allows the OS to determine the TLS cipher suites to use; this is the recommended setting. Otherwise, specify a comma-delimited list of `TlsCipherSuite` enum values to allow just those cipher suites. (This option is only supported on Linux when using .NET Core 3.1 or .NET 5.0 or later.)

Connection Pooling Options

Connection pooling is enabled by default. These options are used to configure it.

Name	Default	Description
Pooling	true	Enables connection pooling. When pooling is enabled, `MySqlConnection.Open` / `OpenAsync` retrieves an open connection from the pool if one is available, and `Close` / `Dispose` / `DisposeAsync` returns the open connection to the pool. If there are no available connections in the pool, and the pool hasn’t reached `MaximumPoolSize` connections, a new connection will be opened; otherwise, the call to `Open` / `OpenAsync` blocks until a connection becomes available or `ConnectionTimeout` is reached.
Connection Lifetime, ConnectionLifeTime	0	Connections that are returned to the pool will be closed if it’s been more than `ConnectionLifeTime` seconds since the connection was created. The default value of zero (0) means pooled connections will never incur a `ConnectionLifeTime` timeout. This can be useful when multiple database servers are being used, as it will force existing connections to be closed, which may spread load more evenly.
Connection Reset, ConnectionReset	`true`	If `true` , all connections retrieved from the pool will have been reset. The default value of `true` ensures that the connection is in the same state whether it’s newly created or retrieved from the pool. A value of `false` avoids making an additional server round trip to reset the connection, but the connection state is not reset, meaning that session variables and other session state changes from any previous use of the connection are carried over. Additionally (if `Connection Reset` is `false` ), when `MySqlConnection.Open` returns a connection from the pool (instead of opening a new one), the connection may be invalid (and throw an exception on first use) if the server has closed the connection.
Defer Connection Reset, DeferConnectionReset		This option was obsoleted in MySqlConnector 2.0.
Connection Idle Timeout, ConnectionIdleTimeout	180	The amount of time (in seconds) that a connection can remain idle in the pool. Any connection above `MinimumPoolSize` connections that is idle for longer than `ConnectionIdleTimeout` is subject to being closed by a background task. The background task runs every minute, or half of `ConnectionIdleTimeout` , whichever is more frequent. A value of zero (0) means pooled connections will never incur a ConnectionIdleTimeout, and if the pool grows to its maximum size, it will never get smaller.
Minimum Pool Size, Min Pool Size, MinimumPoolSize, minpoolsize	0	The minimum number of connections to leave in the pool if ConnectionIdleTimeout is reached.
Maximum Pool Size, Max Pool Size, MaximumPoolsize, maxpoolsize	100	The maximum number of connections allowed in the pool.
DNS Check Interval, DnsCheckInterval	0	The number of seconds between checks for DNS changes, or 0 to disable periodic checks. If the periodic check determines that one of the `Server` hostnames resolves to a different IP address, the pool will be cleared. This is useful in HA scenarios where failover is accomplished by changing the IP address to which a hostname resolves. Existing connections in the pool may have valid TCP connections to a server that is no longer responding or has been marked readonly; clearing the pool (when DNS changes) forces all these existing connections to be reestablished.

Other Options

These are the other options that MySqlConnector supports. They are set to sensible defaults and typically do not need to be tweaked.

Name	Default	Description
Allow Load Local Infile, AllowLoadLocalInfile	false	Allows the `LOAD DATA LOCAL` command to request files from the client. This is disabled by default as a security precaution . In order to use `MySqlBulkLoader` and set its `Local` property to `true` , you must set this option to `True` in your connection string.
Allow Public Key Retrieval, AllowPublicKeyRetrieval	false	If the user account uses `sha256_password` authentication, the password must be protected during transmission; TLS is the preferred mechanism for this, but if it is not available then RSA public key encryption will be used. To specify the server’s RSA public key, use the `ServerRSAPublicKeyFile` connection string setting, or set `AllowPublicKeyRetrieval=True` to allow the client to automatically request the public key from the server. Note that `AllowPublicKeyRetrieval=True` could allow a malicious proxy to perform a MITM attack to get the plaintext password, so it is `False` by default and must be explicitly enabled.
Allow User Variables, AllowUserVariables	false	Allows user-defined variables (prefixed with `@` ) to be used in SQL statements. The default value ( `false` ) only allows `@` -prefixed names to refer to command parameters.
Allow Zero DateTime, AllowZeroDateTime	false	If set to true all `DATE` , `DATETIME` and `TIMESTAMP` columns are returned as `MySqlDateTime` objects instead of `DateTime` . This allows the special “zero” date value `0000-00-00` to be retrieved from the database. If `false` (the default) date columns are returned as `DateTime` values, and an exception is thrown for unrepresentable dates.
Application Name, ApplicationName	null	Sets the program_name connection attribute passed to MySQL Server. This value may be displayed by diagnostic tools, e.g., as the “Program” column in “Client Connections” in MySQL Workbench .
Auto Enlist, AutoEnlist	true	If `true` (default), `MySqlConnection` will detect if there is an active `TransactionScope` when it's opened and automatically enlist in it. If `false` , connections must be manually enlisted by calling `EnlistTransaction` .
Cancellation Timeout, CancellationTimeout	2	The length of time (in seconds) to wait for a query to be canceled when `MySqlCommand.CommandTimeout` expires, or zero for no timeout. If a response isn’t received from the server in this time, the local socket will be closed and a `MySqlException` will be thrown.
Character Set, CharSet, CharacterSet	utf8mb4	MySqlConnector always uses `utf8mb4` to send and receive strings from MySQL Server. This option may be specified (for backwards compatibility) but it will be ignored.
Connection Timeout, Connect Timeout, ConnectionTimeout	15	The length of time (in seconds) to wait for a connection to the server before terminating the attempt and generating an error.
Convert Zero DateTime, ConvertZeroDateTime	false	True to have `MySqlDataReader.GetValue()` and `MySqlDataReader.GetDateTime()` return `DateTime.MinValue` for date or datetime columns that have disallowed values.
DateTime Kind, DateTimeKind	Unspecified	The `DateTimeKind` used when `MySqlDataReader` returns a `DateTime` . If set to `Utc` or `Local` , a `MySqlException` will be thrown if a `DateTime` command parameter has a `Kind` of `Local` or `Utc` , respectively.
Default Command Timeout, Command Timeout, DefaultCommandTimeout	30	The length of time (in seconds) each command can execute before the query is cancelled on the server, or zero to disable timeouts. See the note in the Microsoft documentation for more explanation of how this is determined.
GUID Format, GuidFormat	Default	Determines which column type (if any) should be read as a `System.Guid` . The options include: Char36 All `CHAR(36)` columns are read/written as a `Guid` using lowercase hex with hyphens, which matches `UUID()` . Char32 All `CHAR(32)` columns are read/written as a `Guid` using lowercase hex without hyphens. Binary16 All `BINARY(16)` columns are read/written as a `Guid` using big-endian byte order, which matches `UUID_TO_BIN(x)` . TimeSwapBinary16 All `BINARY(16)` columns are read/written as a `Guid` using big-endian byte order with time parts swapped, which matches `UUID_TO_BIN(x,1)` . LittleEndianBinary16 All `BINARY(16)` columns are read/written as a `Guid` using little-endian byte order, i.e. the byte order used by `Guid.ToByteArray()` and the `Guid(byte[])` constructor. None No column types are automatically read as a `Guid` . Default Same as `Char36` if `OldGuids=False` ; same as `LittleEndianBinary16` if `OldGuids=True` .
Ignore Command Transaction, IgnoreCommandTransaction	false	If `true` , the value of `MySqlCommand.Transaction` is ignored when commands are executed. This matches the Connector/NET behaviour and can make porting code easier. For more information, see Transaction Usage .
Ignore Prepare, IgnorePrepare	false	If `true` , calls to `MySqlCommand.Prepare(Async)` are ignored (and will be no-ops). This option is provided for backwards compatibility with MySQL Connector/NET (before 8.0.23) and should not be used.
Interactive Session, Interactive, InteractiveSession	false	If `true` , the session `wait_timeout` variable is initialized from the global `interactive_timeout` value instead of the global `wait_timeout` value.
Keep Alive, Keepalive	0	TCP Keepalive idle time (in seconds). A value of 0 indicates that the OS default keepalive settings are used; a value greater than 0 is the idle connection time (in seconds) before the first keepalive packet is sent. On Windows, this option is always supported. On non-Windows platforms, this option only takes effect in .NET Core 3.0 and later. For earlier versions of .NET Core, the OS Default keepalive settings are used instead.
No Backslash Escapes, NoBackslashEscapes	false	If `true` , backslashes are not escaped in string parameters. Set this to `true` if the server’s SQL mode includes `NO_BACKSLASH_ESCAPES` .
Old Guids, OldGuids	false	Obsolete; use the `GuidFormat` option instead.
Persist Security Info, PersistSecurityInfo	false	When set to `false` or no (strongly recommended), security-sensitive information, such as the password, is not returned as part of the connection string if the connection is open or has ever been in an open state. Resetting the connection string resets all connection string values, including the password. Recognized values are true, false, yes, and no.
Pipelining	true	When set to `true` , queries will be "pipelined" (when possible) by sending multiple packets to the server before waiting for a response. This improves performance (by reducing latency) but is not compatible with some servers (most notably Amazon Aurora RDS). Set to `false` to disable this behavior.
Server Redirection Mode, ServerRedirectionMode	Disabled	Whether to use server redirection. The options include: Disabled Server redirection is not used. All connections go through the proxy server (if there is one). Preferred If the server supports redirection, a redirected connection will be attempted. If it’s successful, the redirected connection will be used; otherwise, the original connection will be used. Required The server must support redirection, and making a redirected connection must be successful; otherwise, an exception will be thrown. Server Redirection is supported by Azure Database for MySQL if the `redirect_enabled` server parameter is set to `ON` . This option is only respected if `Pooling=True` .
Server RSA Public Key File, ServerRsaPublicKeyFile		For `sha256_password` authentication. See comments under `AllowPublicKeyRetrieval` .
Server SPN, ServerSPN		For MariaDB `auth_gssapi_client` authentication. Specifies the server’s Service Principal Name (to verify that authentication is occurring with the correct server).
Treat Tiny As Boolean, TreatTinyAsBoolean	true	When set to `true` , `TINYINT(1)` values are returned as booleans. Setting this to `false` causes `TINYINT(1)` to be returned as sbyte/byte.
Use Affected Rows, UseAffectedRows	false	When `false` (default), the connection reports found rows instead of changed (affected) rows. Set to `true` to report only the number of rows actually changed by `UPDATE` or `INSERT … ON DUPLICATE KEY UPDATE` statements.
Use Compression, Compress, UseCompression	false	If true (and if the server supports compression), compresses packets sent between client and server. This option is unlikely to be useful in