Hey, I have made an appliacation, but I need to know how to get information from a row only depending on which is it is logged in. Can someone help me with this?

Thanks for your time!

Do you mean fetch a row depending on "who" is logged in?

yeah

just make an associative table that says which user has access to which rows.

Table: users 
Field: user_id
Field: user_name
Field: user_password
 
Table: items
Field: item_id
Field: item_name
Field: item_description
 
Table: access
Field: access_id
Field: access_user_id
Field: access_item_id

When the user logs in, track their user_id in a session or cookie. Then when you need to limit what they can view, use code similar to what is below:

SELECT * 
FROM access
LEFT JOIN items ON item_id = access_item_id
WHERE access_user_id = '[USER_ID]'

does that help, or am I way off target?