Which is faster SQL query statement or Web API

Hi Xamarin Forms

Can I have a help from you guys I want to clear my mind which is much faster when querying data from DB is it directly writing SQL query statement(SELECT statement) or writing a Web API, Lets set aside the security first for I want to know faster return of data from database also my data stores links of image stored in my server rather than storing the actual image to DB

so which is more faster and more recommendable for faster performance of my app

Thanks in Advance