MySql Sink, Unquoted field names.

[pmo-sdr]

Mysql sink sends insert statements not quoting field names, this results on Sql errors when field name is equal to some reserved word.

IE:

When you try to create a field named "load":

com.telefonica.iot.cygnus.sinks.NGSISink[569] : 
BadContextData (SQLException). 
	MYSQL Data insertion error. Query: 
		insert into `traffic_TrafficFlow` 
			(recvTime,fiwareServicePath,entityId,entityType, load,load_md,) 
			values ('2020-04-29 15:22:49.869','/traffic','1','TrafficFlowObserved','178','[]')
		(You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'load,load_md) values ('2020-04-29 15' at line 1). 

Sql statement should be properly quoted to avoid this kind of errors.

[AlvaroVega]

What is the expected sentence?

insert into `traffic_TrafficFlow` 
			('recvTime','fiwareServicePath,'entityId','entityType','load','load_md',) 
			values ('2020-04-29 15:22:49.869','/traffic','1','TrafficFlowObserved','178','[]')

[pmo-sdr]

Actual sentence:

insert into `traffic_TrafficFlow` 
			(recvTime,fiwareServicePath,entityId,entityType, load,load_md)
...

Expeted after fix:

insert into `traffic_TrafficFlow` 
			(`recvTime`,`fiwareServicePath`,`entityId`,`entityType`, `load`,`load_md`)
...

[fgalan]

Once the PR with the fix has been merged, we understand this issue can be closed. Of course if we are wrong, please tell about it so we can reopen.