SQLite currently implements UPDATE by pretending it is SELECTing all the 
fields, except a SET clause causes the expression(s) to be evaluated instead of 
the current field value(s).

Are you using a single prepared statement and binding values (in which case, 
how do you know what values to bind for the "non-updated" columns?) or are you 
creating query strings?

-----Ursprüngliche Nachricht-----
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im 
Auftrag von ghalwasi
Gesendet: Mittwoch, 06. September 2017 17:57
An: sqlite-users@mailinglists.sqlite.org
Betreff: [EXTERNAL] [sqlite] Performance impact of UPDATEing multiple columns 
vs few columns

I am using SQLite C library in my application and I have a question regarding 
updating "mutiple" columns using UPDATE statement.
Lets suppose, my Database table has 10 columns (c1, c2 ... c10). My question is 
that what will be the difference (in context of CPU cycles & performance) if i 
UPDATE multiple columns or only few columns.

Lets say if the requirement is to just update c2 & c3 but if we are updating 
c2, c3,c4,c5,c6,c7

UPDATE db SET c2,c3,c4,c5,c6,c7 WHERE c1=x (c1 is a primary key) or UPDATE db 
SET c2,c3 WHERE c1=x (c1 is a primary key)




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