Selecting from a database into a DataGridView
Three possible problems that I see.



dbConnection = New SqlConnection("Data Source=connectionhere\sqlexpress;Initial Catalog=line_log;Integrated Security=True")


You have a hard-coded connection string. If you want a different database location then you need to edit the code. Perhaps it's better to have the connection string in an editable config file.



The original version which prompted this review ...

strSQL = "SELECT [item] FROM [table] WHERE ([item] = 'value')"


... seems to build the select statement by string manipulation of the value and therefore may be vulnerable to SQL injection.



You have SQL code and Form code in the same source file. It may be better to separate these into different classes so that they can be tested and re-used independently.