如何使用mysql连接数据库？

如何使用PLSQL连接服务器上的数据库，开发初学者都需要会这个问题。下面说一下步骤，帮助大家配置host并成功查询数据。

1、首先鼠标右键PLSQL，选择属性，打开PLSQL所在文件夹位置。

2、在文件夹中，找到instantclient文件夹。这里将该文件移出到PLSQL安装文件外，方便之后修改。

3、然后在instantclient下，找到tnsnames.ora，用编辑器打开。

4、在tnsnames.ora中，可以配置数据库连接。数据库名称、协议类型、host、port、sid。配置好之后，保存。

5、打开PLSQL，输入username、password，选择到配置的数据库，进行连接。点击“file”--“new”--“SQL Window”，打开窗口，输入查询命令，F8执行，连接成功了。

The port 3306 is the default MySql port.

The value is ignored if Unix socket is used.

Use this to connect to a server in a replicated server configuration without concern on which server to use.

Use SSL if the server supports it, but allow connection in all cases

This option is available from Connector/NET version 6.2.1

Always use SSL. Deny connection if server does not support SSL.

This option is available from Connector/NET version 6.2.1

This option is available from Connector/NET version 6.2.1

This option is available from Connector/NET version 6.2.1

This option is available from Connector/NET version 6.2.1

This option is available from Connector/NET version 5.2.2

Returns a MySqlDateTime object for invalid values and a System.DateTime object for valid values

Returns System.DateTime.MinValue valued System.DateTime object for invalid values and a System.DateTime object for valid values.

The use of auto enlist transactionscope (default behaviour) could cause trouble in medium trust environments.

Default behaviour is that parameters for stored routines (stored procedures) are checked against the server

Some permissions and value casting related errors reported fixed when using this connection option.

The default behaviour is to read tables mysql.proc/INFORMATION_SCHEMA.ROUTINES and try to map provided command parameter values to the called procedures parameters and type cast values accordingly.

This can be troublesome if permissions to the (aforementioned) sproc info tables are insufficient.

The driver will not automatically map the parameters so you must manually set parameter types and you must also make sure to add the parameters to the command object in the exact order as appeared in the procedure definition.

This option is available from Connector/NET version 5.0.4

Specifying DefaultTableCacheAge is optional, default value is 60 seconds.

This option is available from Connector/NET version 6.4

This option is available from Connector/NET version 5.2.6

From version 6.2 idle connections are removed from the pool, freeing resources on the client (sockets) and the server (sockets and threads). Do not manually keep (global) connections and open close. Keep connection object creation and disposal as tight as possible, this might be counterintuitive but pooling mechanisms will take care of caching well and your code will be cleaner.

This is the default behaviour.

Default values are 0 and 100.

Makes an additional round trip to the server when obtaining a connection from the pool and connection state will be reset.

This is useful in load balancing scenarios when available servers change you don't want 100 constant connections in the pool pointing to only one server.

Specified in seconds, the amount of time after connection object creation the connection will be destroyed. Destruction will only happen when connections are returned to pool.

A connection might be long lived in the pool, however the connections server settings are updated (SHOW VARIABLES command) each time returned to the pool. This makes the client use of the connection object up to date with the correct server settings. However this causes a round trip and to optimize pooling performance this behaviour can be turned off.

This option is available from Connector/NET version 6.3

This option is available from Connector/NET version 6.4.4

The Windows Native Authentication Plugin must be installed for this to work.

Number of seconds between each keep-alive package send.

This option is available from Connector/NET version 6.1.1

The default is 25, meaning that stored procedure meta data (such as input/output data types etc) for the latest 25 called procedures will be cached in client memory.

This option is available from Connector/NET version 5.0.2

This enables Visual Studio wizards that bracket symbols with [] to work with Connector/Net. This option incurs a performance hit, so should only be used if necessary.

This option is available from Connector/NET version 6.3.1

Use this one to specify a default command timeout for the connection. Please note that the property in the connection string does not supercede the individual command timeout property on an individual command object.

This option is available from Connector/NET version 5.1.4.

Use this one to specify the length in seconds to wait for a server connection before terminating the attempt and receive an error.

Use this one to instruct the provider to ignore any command prepare statements and prevent corruption issues with server side prepared statements.

The option was added in Connector/NET version 5.0.3 and Connector/NET version 1.0.9.

Use this one to specify which network protocol to use for the connection.

"socket" is the default value used if the key isn't specified. Value "tcp" is an equivalent for "socket".

Use "pipe" to use a named pipes connection, "unix" for a Unix socket connection and "memory" to use MySQL shared memory.

It's possible to explicit set the shared memory object name used for communication.

It's possible to explicit set the pipe name used for communication, if not set, 'mysql' is the default value.

It is the port value of -1 that tells the driver to use named pipes network protocol. This is available on Windows only. The value is ignored if Unix socket is used.

It's possible to explicit set the shared memory object name used for communication.

Use this one to specify which character set to use to encode queries sent to the server.

Note! Use lower case value utf8 and not upper case UTF8 as this will fail.

Note that resultsets still are returned in the character set of the data returned.

一、xp/2003添加防火墙例外端口

打开防火墙,选择例外选项卡，添加端口

名称：mysqlport

端口号：3306

选中TCP

二、win7添加防火墙例外端口

入站规则设置

第一步 选择 入站规则 然后 新建规则，选择 端口，然后下一步

第二步 选择TCP 选择特定端口 然后输入端口，如有多个端口需要用逗号隔开了 例如: 3306

第三步 选择允许连接

第四步 选择配置文件

第五步 输入规则名称 mysqlport

出站规则设置

第一步 选择出站规则 然后 新建规则，选择 端口，然后下一步

第二步 选择TCP 选择特定端口 然后输入端口，如有多个端口需要用逗号隔开了 例如: 3306

第三步 选择允许连接

第四步 选择配置文件

第五步 输入规则名称 mysqlport（或者无特殊要求下直接关闭防火墙）

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