Error: ER_TRUNCATED_WRONG_VALUE

Hello, I need help with a school project.
I am using an HTML POST to send data to nodered. But after some processing, I have BDD errors

My function :

msg.tps = msg.payload; //msg.tps=time seconde (structure BDD type float)
msg.num_prod =msg.payload.Num_prod; //num_prod=2 (structure BDD type int and test text)

msg.topic = "UPDATE production set duree = '"+ msg.tps +"' WHERE num_prod='"+ msg.num_prod +"';"
return [msg];

when i replace num_prod='"+ msg.num_prod +"' BY num_prod='2' It's ok

Error is : erreur Error: ER_TRUNCATED_WRONG_VALUE: Truncated incorrect DOUBLE value: undefined

thanks for your help
sorry for my english i'm french

Welcome to the forum.

Add a Debug node showing what is coming out of your function node and see what it shows.