What I am trying to do is reduce the time needed to aggregate data by producing a roll-up table of sorts. When I insert a record, an after insert trigger is fired which will update the correct row. I would update all of the columns of the roll-up table if I need to, but since there are 25 columns in the table and each insert will only update 2 of them, I would rather be able to dynamically select the columns to update. My current update statement in the after insert trigger looks similar to this:
update peek_at_chu.organization_data_state_log odsl
inner join ( select
lookUpID as org_data_lookup,
i.interval_id,
peek_at_chu.Get_Time_Durration_In_Interval1('s', new.start_time, new.end_time, i.start_time, i.end_time) as time_in_int,
new.phone_state_id
from
(peek_at_chu.interval_info i
join peek_at_chu.interval_step int_s on i.interval_step_id = int_s.interval_step_id)) as usl on odsl.org_date_lookup_id = usl.org_data_lookup
and odsl.interval_id = usl.interval_id
set
total_seconds = total_seconds + usl.time_in_int,
case new.phone_state_id
when 2 then
available_seconds = available_seconds + time_in_int
end;
In this, lookUpID is a variable previously declared in the trigger. The field that will dictate which field of the roll-up table to update is new.phone_state_id. The phone_state_id's are not consistent, that is some numbers are skipped in this table, so an update based on column number is out the window unless I create a mapping.
The case option throws an error but I am hoping to use something similar to that instead of 25 if statements if I can.
You have to update all the columns, but use a conditional to determine whether to give it a new value or keep the old value:
set total_seconds = total_seconds + usl.time_in_int,
available_seconds = IF(new.phone_state_id = 2, available_seconds + time_in_int, available_seconds)
Repeat the pattern in the last line for all the other columns that need to be updated conditionally.
Related
si have a db field that i want to use to track intervals. i want to push completed intervals onto the db field when they are completed. to wit:
intervals = '10'
intervals = '1020' <-- pushing 20 onto the field
intervals = '102040' <-- pushing 40 onto the field
intervals = '102040SP' <-- pushing SP onto the field
the values will never decrement (and order doesn't really matter, if that's a factor), so i'm only looking for a way to UPDATE the field, but i have no idea how to do that because UPDATE tbl SET ... just overwrites the existing contents. i looked into CONCAT, but that works with variables the user provides, not with existing data AND additional user data. if i were to write some PSEUDO code, it might look like this:
UPDATE tbl PUSHTO intervals VALUE newInterval WHERE id='id' AND date='date'
so. can anybody help me out here? there has to be a way to do this. :)
An update with concatenation is what you want here:
UPDATE tbl
SET interval = CONCAT(interval, newInterval)
WHERE id = 'id' AND date = 'date';
If you wanted to make the update even in the event that newInterval might be null, you could try:
UPDATE tbl
SET interval = CONCAT(interval, COALESCE(newInterval, ''))
WHERE id = 'id' AND date = 'date';
I'm trying to replace null values in one table with values from a second table, based on matches from other columns in both tables. While the code does not result in error, it does not stop running, producing an unending "running query" signal. code is here
UPDATE pl_building b
INNER JOIN pl_grt t
ON b.INST = t.inst
SET b.Utuition=t.tuition
WHERE b.UtUITION = 0;
You should not update on join tables.
I am not sure what field you want to update, but your SQL should look like this:
UPDATE pl_building b
SET b.Utuition= (select t.tuition from pl_grt t ON b.INST = t.inst)
WHERE b.UtUITION = 0;
Make sure :
1) You have an index on t.inst table column and maybe also on b.UtUITION
2) Relationship between b.INST = t.inst is unique. Never returns more than 1 row.
SQL:
$mysqli->query("UPDATE results
SET result_value = '".$row[0]['logo_value']."'
WHERE logo_id = '".$mysqli->real_escape_string($_GET['logo_id'])."'
AND user_id = '".$user_data[0]['user_id']."'");
This results table also contains result_tries I'd like to fetch before doing update, so I can use it to modify result_value... Is there a way to do it in a single shot instead of first doing select and than doing update?
Is this possible?
Basically:
UPDATE results SET result_value = result_value + $row[0][logo_value]
for just a simple addition. You CAN use existing fields in the record being updated as part of the update, so if you don't want just addition, there's not too many limits on what logic you can use instead of just x = x + y.
I am trying to figure out how to update a row in one table, setting a column value equal to a value in a different table. Here's an example:
movies:
movie_id | movie_price
movies_attended:
attended_id | attended_movie_id | attended_movie_price
Now, this is kind of a stupid example, but supposed that for some reason there is a row in movies_attended that does not have the correct attended_movies_price in it and so it needs to be updated.
How should a query be written to update the movies_attended table, setting movies_attended.attended_movie_price = movies.movie_price?
I tried something similar to the following, but it did not work:
update movies_attended, movies
set movies_attended.attended_movie_price = movies.movie_price
where movies_attended.attended_movie_id = movies.movie_id
AND attended_id = [the id of the row we want to update]
When you say "it did not work", do you mean that it reported 0 rows updated, or did the statement cause the database raise an exception?
Your example statement appears to be of the form:
UPDATE movies_attended a
JOIN movies m
ON a.attended_movie_id = m.movie_id
SET a.attended_movie_price = m.movie_price
WHERE a.attended_id = ?
(We typically prefer the JOIN ... ON ... style syntax to the comma join operator and the join predicates in the WHERE clause.)
I have no explanation as to why this statement would "not work".
It's possible this would report 0 rows affected, if no rows satisfy the predicates. It would also report 0 rows affected if the rows that would be changed do not require any changes... that is, the existing value in attended_movie_price already matches the value being assigned to it.
Normally, before running an update statement like that, I write it as a SELECT first, and see what values are returned...
By replacing the UPDATE keyword with SELECT ... FROM, and removing the SET clause:
SELECT m.movie_price AS new_val
, a.attended_movie_price AS old_val
, a.attended_id
FROM UPDATE movies_attended a
JOIN movies m
ON a.attended_movie_id = m.movie_id
WHERE a.attended_id = ?
This is actually a bad database design. You don't need movie price in two tables.
But, if you just need this, it goes something along this:
UPDATE movies_attended
INNER JOIN
movies
ON movies_attended.attended_movie_id = movies.movie_id
SET movies_attended.attended_movie_price = movie.movie_price
I have two tables, one a options table (rot) that has the metrics of a set of rooms and another that has the current state of the rooms (rt). I want to have a daily event that updates the cost_to_date in the rt using the values stored in the rot.
When I tried the SQL:
UPDATE room_tbl SET COST_TO_DATE_rt = COST_TO_DATE_rt + (
SELECT PerDiem_rot FROM room_options_tbl, room_tbl
WHERE `ROOM_OPT_ID_rot` = `ROOM_OPT_ID_rt`
AND `ADULT_COUNT_rot` = `ADULT_COUNT_rt`)
I get the error: #1093 - You can't specify target table 'room_tbl' for update in FROM clause
My searching for a solution led me to try a temporary table using aliasing but my attempts at it have all resulted in syntax errors. Any help would be appreciated.
You can't use a query because its not supported by MySQL in an update clause
From 13.2.10. UPDATE Syntax
Currently, you cannot update a table and select from the same table in a subquery.
Instead try the following
UPDATE room_options_tbl, room_tbl
SET COST_TO_DATE_rt = COST_TO_DATE_rt + PerDiem_rot
WHERE `ROOM_OPT_ID_rot` = `ROOM_OPT_ID_rt`
AND `ADULT_COUNT_rot` = `ADULT_COUNT_rt`