Question

Hi I am new to SQL database.

I have two tables one is a “Master” and other is “Sub” like this

Master 
uid(primary key)         f_name            l_name
 1                        fAaa              lAaa
 2                        fBbb              lBbb

second table

Sub 
tid(primary key)         uid(foreign key)      time           is_free
  1                        1                   1:00AM           0
  2                        1                   2:00AM           1 
  3                        1                   3:00AM           0 
  4                        2                   1:30PM           0
  5                        2                   2:30PM           1   

from both table we can say that user fAaa lAaa is free at 2:00AM and NOT free at 1:00AM and 3:00AM.

now I want to update like this, for user 1(fAaa lAaa), I want to delete time 2:00AM and want to insert new two time like 5:00AM and 6:00AM for user 1 than what should be my join query for update.

please help me!
Thanks

Answer 1

Like this?

DELETE FROM secondtable WHERE uid = 1 AND (time = "1:00AM" OR time = "2:00AM");
INSERT INTO secondtable (uid, time) VALUES (1, "5:00AM"), (1, "6:00AM");

Or

UPDATE secondtable SET time = "5:00AM" WHERE uid = 1 AND time = "1:00AM";
UPDATE secondtable SET time = "6:00AM" WHERE uid = 1 AND time = "2:00AM";

This is some pretty basic stuff, I recommend you do a search for “sql delete from”, “sql insert into”, “sql update” and look for beginner tutorials.