What I can deduce from your explanation is, you are trying to link two input components using row(main) link. You will obviously face issues in this as Row(main) is used to pass on the data flow from one component to the other. But in your case both are source components which are holding the data. So, to overcome this you need to use an orchestration component called tFlowToIterate. This component is used to read data line by line from the input flow and then store the data entries in iterative global variables.
Now you can use the global variables created from the output of tMysqlInput component by the tFlowToIterate in your component query:
Here rowX will be the name of the incoming row from the tFlowToIterate component and ColName will be the name of the column of your database.