I am attempting to update a boolean column in one table based upon the values in a second.
UPDATE channels
SET contains_photos = TRUE
WHERE id IN (SELECT unnest(ancestors)
FROM channel_tree WHERE id = 11329);
The channel_tree.ancestors column contains an array of channel IDs. The above is failing with the following error:
ERROR: cannot TRUNCATE "channel_tree" because it is being used by active queries in this session
The overriding goal is to set the contains_photos column to true for all ancestors of a given channel. Any one know how best to alleviate this error, or even an alternative solution?
No idea why your error says TRUNCATE. It sounds like you have a trigger or rule that is doing a truncate that we can't see.
Here's some alternative ways of doing that same query:
UPDATE channels
SET contains_photos = TRUE
WHERE id = ANY (SELECT ancestors
FROM channel_tree WHERE id = 11329);
Or with a join:
UPDATE channels
SET contains_photos = TRUE
FROM channel_tree
WHERE channels.id = ANY (channel_tree.ancestors)
AND channel_tree.id = 11329;
Related
I have a table where all values of the column requested are false. I perform an action in python and want to update the first row where requested is false to true. So, after the first execution in python, the first row is set to true. After the second execution - since requested in the first row is now true - the second row is set to true and so on. My sql statement looks like this:
UPDATE timeframes SET requested = TRUE
WHERE requested = (
SELECT requested FROM timeframes
WHERE requested = FALSE
ORDER BY id
LIMIT 1);
This statement sets ALL the values in requested to true. I don't know why. If I execute the subquery as its own query, it only returns the first row. So in my opinion the update statement should therefore only set that specific row to true. Any idea as to why my statement doesn't work and how to improve it?
EDIT: Changing WHERE requested IN to WHERE id IN worked. The statement should look like this:
UPDATE timeframes SET requested = TRUE
WHERE id = (
SELECT id FROM timeframes
WHERE requested = FALSE
ORDER BY id
LIMIT 1);
your update executes ...
where requestet = false
to update only the first row with a unique id change your update statement to
UPDATE timeframes SET requested = TRUE
WHERE id = (
SELECT id FROM timeframes
WHERE requested = FALSE
ORDER BY id
LIMIT 1);
as written in the comments, by amadan, you can either use where id in, or better in this situation where id =
Sample data:
I am trying update a column with values from multiple columns in another table if two columns match.
Consider the following query:
UPDATE application_table
SET asset_list = asset_table.asset_name
FROM asset_table
WHERE application_table.application_name = asset_table.applications;
My table structure is:
application_table:
"asset_list"; "text[]"
"application_name"; "character varying"
asset_table:
"asset_name"; "character varying"
"applications"; "character varying"
I get the following error:
ERROR: column "asset_list" is of type text[] but expression is of type character varying
Line 12 SET asset_list = asset_table.asset_name
What you need to do is aggregate the asset_name per applications value and set asset_list to that aggregated value.
Problem is you can't do something like
UPDATE ..
SET asset_list = ARRAY_AGG(asset_name)
FROM ...
because aggregate functions are not allowed in updates like that.
So here's two other ways to do it:
UPDATE app_table
SET asset_list = _asset_list
FROM (
SELECT applications, ARRAY_AGG(asset_name ORDER BY asset_name) AS _asset_list
FROM asset_table
GROUP BY applications
) AS a
WHERE app_name = applications;
https://www.db-fiddle.com/f/pKB5k6Lexwzqv6ZbCCdJay/0
This first builds a result set of distinct application names and an array of all the asset_names for each of the app names. Then it updates the table as usual with that array value.
Another way is:
UPDATE app_table
SET asset_list = (SELECT ARRAY_AGG(asset_name ORDER BY asset_name)
FROM asset_table
WHERE applications = app_name)
;
https://www.db-fiddle.com/f/8oVWsubXW93n142gtZYLXB/0
This will update every record in app_table, and calculates the array value on the fly for every record.
I have the following code in Postgres
select op.url from identity.legal_entity le
join identity.profile op on le.legal_entity_id =op.legal_entity_id
where op.global_id = '8wyvr9wkd7kpg1n0q4klhkc4g'
which returns 1 row.
Then I try to update the url field with the following:
update identity.profile
set url = 'htpp:sam'
where identity.profile.url in (
select op.url from identity.legal_entity le
join identity.profile op on le.legal_entity_id =op.legal_entity_id
where global_id = '8wyvr9wkd7kpg1n0q4klhkc4g'
);
But the above ends up updating more than 1 row, actually all of the rows of the identity table.
I would assume since the first postgres statement returns one row, only one row at most can be updated, but I am getting the wrong effect where all of the rows are being updated. Why ?? Please help a nubie fix the above update statement.
Instead of using profile.url to identify the row you want to update, use the primary key. That is what it is there for.
So if the primary key column is called id, the statement could be modified to:
UPDATE identity.profile
SET ...
WHERE identity.profile.id IN (SELECT op.id FROM ...);
But you can do this much simpler in PostgreSQL with
UPDATE identity.profile op
SET url = 'htpp:sam'
FROM identity.legal_entity le
WHERE le.legal_entity_id = op.legal_entity_id
AND le.global_id = '8wyvr9wkd7kpg1n0q4klhkc4g';
I need to update a few thousand rows in my Postgres table using the result of a array_agg and spatial lookup.
The query needs to take the geometry of the parent table, and return an array of the matching row IDs in the other table. It may return no IDs or potentially 2-3 IDs.
I've tried to use an UPDATE FROM but I can't seem to pass into the subquery the parent table geom column for the SELECT. I can't see any way of doing a JOIN between the 2 tables.
Here is what I currently have:
UPDATE lrc_wales_data.records
SET lrc_array = subquery.lrc_array
FROM (
SELECT array_agg(wales_lrcs.gid) AS lrc_array
FROM layers.wales_lrcs
WHERE st_dwithin(records.geom_poly, wales_lrcs.geom, 0)
) AS subquery
WHERE records.lrc = 'nrw';
The error I get is:
ERROR: invalid reference to FROM-clause entry for table "records"
LINE 7: WHERE st_dwithin(records.geom_poly, wales_lrcs.geom, 0)
Is this even possible?
Many thanks,
Steve
Realised there was no need to use SET FROM. I could just use a sub query directly in the SET:
UPDATE lrc_wales_data.records
SET lrc_array = (
SELECT array_agg(wales_lrcs.gid) AS lrc
FROM layers.wales_lrcs
WHERE st_dwithin(records.geom_poly, wales_lrcs.geom, 0)
)
WHERE records.lrc = 'nrw';
I have a table where I have added a new column, and I want to write a SQL statement to update that column based on existing information. Here are the two tables and the relevant columns
'leagues'
=> id
=> league_key
=> league_id (this is the new column)
'permissions'
=> id
=> league_key
Now, what I want to do, in plain English, is this
Set leagues.league_id to be permissions.id for each value of permissions.league_key
I had tried SQL like this:
UPDATE leagues
SET league_id =
(SELECT id FROM permissions WHERE league_key =
(SELECT distinct(league_key) FROM leagues))
WHERE league_key = (SELECT distinct(league_key) FROM leagues)
but I am getting an error message that says
ERROR: more than one row returned by a subquery used as an expression
Any help for this would be greatly appreciated
Based on your requirements of
Set leagues.league_id to be permissions.id for each value of permissions.league_key
This does that.
UPDATE leagues
SET league_id = permissions_id
FROM permissions
WHERE permissions.league_key = leagues.league_key;
When you do a subquery as an expression, it can't return a result set. Your subquery must evaluate to a single result. The error that you are seeing is because one of your subqueries returns more than one value.
Here is the relevant documentation for pg84: