The problem is they exist in both tables. If I gave you 2 apples, one red, which you place in your left hand, and one green which you place in your right hand, and I asked you ""hat colour is the apple", which colour would you give? I might want to know the colour of the apple in your left hand (red), but you have know way of knowing. If I asked you, what colour is the apple in your left hand, you can safely answer "red".

The same is true here. the fields start_Date and End_date exist in both the tables JOURNAL and inserted. If you ask SQL to give you the value of start_date it doesn't know what table to look at, so it presents an error.

The alias for your inserted table is i, so this is the lias you need here (for example, i.start_date). Make sense?