Tried to monitor the Uptime of a MySQL database with this query Show status like 'Uptime'. But I get the error message 'Could not convert variant of type (UnicodeString) into type (Double)'
As the PRTGToolsFamily user confirmed/pointed out, that query outputs more than a single value, PRTG will only receive a single value as query result, since the query returns the variable name column too, that causes the sensor to go into error.
Your current query would be equivalent to this:
SELECT * FROM information_schema.`GLOBAL_STATUS`
WHERE VARIABLE_NAME IN ('UPTIME')But as documented in the PRTG Manual:
| Enter a valid SQL statement to execute on the server. In your SELECT statement, please specify the field name explicitly. Do not use SELECT *! For example, a correct expression could be: SELECT AVG(UnitPrice) FROM Products. |
Consider using something like this in the sensor instead:
SELECT VARIABLE_VALUE FROM information_schema.`GLOBAL_STATUS`
WHERE VARIABLE_NAME IN ('UPTIME')That will return only:
| 1592 |
Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.
