Use variable in SQL query

[gegar]

Hello

I Know, the use the variable in SQl Query

But in data source in select in Query Text, I have a Join

LEFT JOIN observacion ON asig.ano_lectivo=observacion.ano_lectivo AND asig.observgrado = observacion.grado AND asig.observasign = observacion.codigoasig AND notas.obs1per{ggs_per} = observacion.codobservacion

{ggs_per} have the value 1 and the View Data is working good.

But in Preview i have the next error

[1064] You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '{ggs_per} = observacion.codobservacion LEFT JOIN promalumnos pa ON pa.ano_lecti' at line 1

Why?

Thank you for your help.

[Lech Kulikowski]

Hello,

Please send us a sample report and test data which reproduces the issue for analysis.

Thank you.