====MySQL Historical Driver Information====

===Source Properties===

When setting up the MySQL data source, you'll be asked to specify...

^Option^Use^
|Host|The host name or IP address of your MySQL server|
|Port|The port that the MySQL server runs on (normally 3306)|
|Database|The name of the MySQL database to use|
|Username|The username (with read-only access) to use to connect|
|Password|The password that goes with the above username*|
|Table|The name of the table to query|
|Lookup Field|The field that gives you the 'name' of the value - used to connect a single ARDI property with a single row in your database|
|Date Stamp|The name of the //date// column in your database.|
|Value|The name of the column that contains the value you are looking for|
|Filter|**Optional** - An additional filter to add to the SQL query|
|Date Format|The [[date format|date format]] that the //Date Stamp// column is in.|
|Date Distribution|If the history is recorded in a [[synchronised|synchronised]] fashion.|
|Timezone|The timezone that the dates are stored in. Normally these are your local timezone, or UTC|

* Note that this password is visible to all administrative users, which is why you should ensure that the user account is //read only// and can not make changes to the underlying database.

===Link Properties===

These are the options that appear when you link a property to a text data source...

^Option^Use^
|Lookup|The value of the lookup column|

===How It Works===

As an example, let's look at a simple database layout...

^Date^Name^Value^
|2016-01-01 12:15|ALPHA_TEMP|24.04|
|2016-01-01 12:15|BETA_PRESS|2891|
|2016-01-01 12:15|BETA_TEMP|16.29|
|2016-01-01 11:15|ALPHA_TEMP|29.04|
|2016-01-01 11:15|BETA_PRESS|2231|
|2016-01-01 11:15|BETA_TEMP|20.29|

If we wanted to connect to the latest values in this table, we would set the columns of our **data source** so that...

  * Lookup Field = //Name//
  * Value = //Value//
  * Date = //Date//

Then, if we had an asset called "Beta", when we linked the "Pressure" property to data, we would set...

   * Lookup = //BETA_PRESS//

The driver checks for the **Lookup Field** that matches the **Lookup** of the data link and returns the value in the **Value** field.