I want to update the content of a table calls VIDEO_TAGS which contains 3 columns, fk_video_id, principal (not too important), and tag_value.
I want to do an update as follows,
"UPDATE VIDEO_TAGS
SET tag_value= :newTag
where tag_value= :oldTag
and fk_video_id = (SELECT FROM VIDEO_TAGS fk_video_id where tag_value= :productName)"
but it is clear that the sub-query will return many elements, while I only need one element -more than one row returned by a subquery used as an expression ERROR-.
my question is how to edit the sub-query to get the one element that I need? Thank you
Related
I have a mongo database and I'm trying to write an Eloquent code to change some fields before using them in WHERE or ORDER BY clauses. something like this SQL query:
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Where ht.title = 'OrangeHotel'
-- or --
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Order by ht.title
sometimes there is no other table and I just need to use calculated field in Where or Order By clause:
Select *
from agency
Where func(agency_admin) = 'testAdmin'
Select *
from agency
Order by func(agency_admin)
where func() is my custom function.
any suggestion?
and I have read Laravel 4/5, order by a foreign column for half of my problem, but I don't know how can I use it.
For the first query: mongodb only support "join" partially with the aggregation pipeline, which limits your aggregation in one collection. For "join"s between different collections/tables, just select from collections one by one, first the one containing the "where" field, then the one who should "join" with the former, and so on.
The second question just puzzled me for some minutes until I see this question and realized it's the same as your first question: sort the collection containing your sort field and retrive some data, then go to another.
For the 3rd question, this question should serve you well.
Basically I want to retrieve rows of data that meet my clause conditions using Power Query.
I got 400 rows of lookup values in my spreadsheet.
Each row represent 1 lookup code for example, code AAA1, AAB2 and so on
So lets say I have a select statement and I want to construct the where clauses using the above codes so my end sql statement will look like
select * from MyTable where Conditions in ('AA1', 'AAB2')
so so far I have this
let
Source = Excel.CurrentWorkbook(){[Name="Table5"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Form ID",
Int64.Type}}),
test = Sql.Database("myserver", "myDB", [Query="SELECT * FROM myTable where" & #"Changed Type" & "])"
in
test
Obviously that didnt work but thats my pseduo scenario anyway.
Please could you advice what to do?
Thank you
Peddie
I would create a "lookup" Power Query based on the Excel table. I would set the "Load To" properties to "Only Create Connection".
Then I would start the main Query by connecting to the SQL server using the Navigator to select "MyTable". Then I would add a Merge step to the main Query, to join to the "lookup" Query, matching the "Conditions" column to the "lookup" code. I would set the Join Type to "Inner". The Merge properties window will show you visually if the 2 columns you select actually contain matching data.
This approach does not require any coding, and is easier to build, extend and maintain.
Mike Honey's join is best for your problem, but here's a more general solution if you find yourself needing other logic in your where clause.
Normally Power query only generates row filters on an equality expression, but you can put any code you want in a Table.SelectRows filter, like each List.Contains({"AA1", "AAB2"}, [Conditions])
So for your table, your query would look something like:
let
Source = Excel.CurrentWorkbook(){[Name="Table5"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Form ID", Int64.Type}}),
test = Sql.Database("myserver", "myDB"),
yourTable = test{[Name="myTable"]}[Data],
filtered = Table.SelectRows(yourTable, each List.Contains(#"Changed Type"[Form ID], [Conditions]))
in
filtered
The main downside to using the library functions is that Table.SelectRows only knows how to generate SQL where clauses for specific expression patterns, so the row filter probably runs on your machine after downloading the whole table, instead of having the Sql Server run the filter.
I'm new to PostgreSQL and I am working on a function to return the word locations for a searched word.
I want to first narrow down the text fields the search has to go though to make sure it is a relevant result from the database.
My table name is 'testing' then the text field column is called 'context' and the line number where it is located is called 'line_number'. Where the context text is associated with a specific line_number.
Right now my ranking code looks like this:
select line_number into lineLocation
from (
SELECT
testing.line_number,
ts_rank_cd(to_tsvector('english', testing.context),
to_tsquery('Cats & Dogs & Kids')) AS score
FROM Testing
) ranking
WHERE score >0
ORDER BY score DESC;
Return QUERY select * from lineLocation;
When I try to print out lineLocation as a return query, it works in reporting the new ranked line numbers 22,19,21,20,17,13 each returned in their own column.
My problem now is that I want to search each of those lines (22 ... 13) for a key word like "dog" and return its position
Obtaining the text for that by using:
select context into sample from testing
where testing.line_number = lineLocation;
If I try to just decrement the lineLocation in a loop like lineLocation -i
It goes out of order, and will eventually search context that is not relevant.
Is there any type of 'read next line' function I could use?
I am looking for a way to loop through the ranked result line numbers
EDIT I then go on to use a for loop where I want it to read through all of the rows of text in the column context from the ranked results
The problem I am having with this is that it only reads the first row of text in the column 'context' and I need it to look at all of the rows that are returned by the ranked search
Ended up creating a ranking function of its own, and inserting the results of that text search into another table with a serial increment column.
filled the values of the new table (ranked_results) with this code:
INSERT INTO ranked_results(sentence) VALUES (columnRanking());
I also had to create a function to delete/reset the columns in the new table upon insertion of more lines.
TRUNCATE table ranked_results RESTART IDENTITY;
SELECT matnr ersda ernam laeda
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
UP TO 100 ROWS.
At this point I have 100 entries in the itab gt_mara.
SELECT aenam vpsta pstat lvorm mtart
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
FOR ALL ENTRIES IN gt_mara
WHERE matnr = gt_mara-matnr AND
ersda = gt_mara-ersda AND
ernam = gt_mara-ernam AND
laeda = gt_mara-laeda.
At this point I have 59 entries. Which makes sense. This code is buggy, because it might be modifying the selection criteria at run time.
Anyway what i intended was this: select the first 4 fields of the table at one point, and then select the other 5 at some other.
Of course, this is just an example. Perhaps the second select would be done on a different table with the same key or with a different number of fields.
So can this even be done?
Are there more efficient methods to achieve this than what comes to my mind by default (redoing the complete select) ?
Ok I think the essence of your question is more about whether you can update certain unfilled fields in an internal table directly through a second select statement.
The answer is no. Your second select statement would replace the contents in table gt_mara, so you would be left with an internal table where the first 4 fields are blank, and the last 5 are filled.
The best you could do is something like this:
SELECT matnr ersda ernam laeda
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
UP TO 100 ROWS.
SELECT matnr aenam vpsta pstat lvorm mtart
FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara2
FOR ALL ENTRIES IN gt_mara
WHERE matnr = gt_mara-matnr AND
ersda = gt_mara-ersda AND
ernam = gt_mara-ernam AND
laeda = gt_mara-laeda.
loop at gt_mara2 into ls_mara.
modify gt_mara from ls_mara transporting aenam vpsta pstat lvorm mtart
where matnr = ls_mara-matnr.
endloop.
This is obviously quite inefficient, which is why you would always try to make the database do as much of the work for you before you bring the data back to the application server. Obviously if the data is coming from the same table selecting it all in one go is going to be your best option. In most cases even if the data is in different tables you would be better off creating a view or using a join.
In rare cases it is necessary to loop at your internal table to fill in some fields that were not available to you when you did the original select.
Either SELECT everything you need right away (which is the preferred solution if the data comes from the same table) or SELECT the additional stuff later (which is a good idea if the stuff comes from a different table that is not used for the first selection). For assembling the result set, the database usually needs to access the entire dataset anyway, so it doesn't really hurt to select some additional fields - in contrast to hitting the database again with a massive SELECT statement (if the FOR ALL ENTRIES table gets large). Also bear in mind that - depending on the kind of processing you're doing - the contents of the table might have changed in the meantime. If the database transaction (LUW) ends (which is always the case between dialog steps), you loose the database-level transaction isolation.
I have a table listing (gameid, playerid, team, max_minions) and I want to get the players within each team that have the lowest max_minions (within each team, within each game). I.e. I want a list (gameid, team, playerid_with_lowest_minions) for each game/team combination.
I tried this:
SELECT * FROM MinionView GROUP BY gameid, team
HAVING MIN(max_minions) = max_minions;
Unfortunately, this doesn't seem to work as it seems to select a random row from the available rows for each (gameid, team) and then does the HAVING comparison. If the randomly selected row doesn't match, it's simply skipped.
Using WHERE won't work either since you can't use aggregate functions within WHERE clauses.
LIMIT won't work since I have many more games and LIMIT limits the total number of rows returned.
Is there any way to do this without adding another table/view that contains (gameid, teamid, MIN(max_minions))?
Example data:
sqlite> SELECT * FROM MinionView;
gameid|playerid|team|champion|max_minions
21|49|100|Champ1|124
21|52|100|Champ2|18
21|53|100|Champ3|303
21|54|200|Champ4|356
21|57|200|Champ5|180
21|58|200|Champ6|21
64|49|100|Champ7|111
64|50|100|Champ8|208
64|53|100|Champ9|8
64|54|200|Champ0|226
64|55|200|ChampA|182
64|58|200|ChampB|15
...
Expected result (I mostly care about playerid, but included champion, max_minions here for better overview):
21|52|100|Champ2|18
21|58|200|Champ6|21
64|53|100|Champ9|8
64|58|200|ChampB|15
...
I'm using Sqlite3 under Python 3.1 if that matters.
This is in SQL Server, hopefully the syntax works for you too:
SELECT
MV.*
FROM
(
SELECT
team, gameid, min(max_minions) as maxmin
FROM
MinionView
GROUP BY
team, gameid
) groups
JOIN MinionView MV ON
MV.team = groups.team
AND MV.gameid = groups.gameid
AND MV.max_minions = groups.maxmin
In words, first you make the usual grouping query (the nested one). At this point you have the min value for each group but you don't know to which row it belongs. For this you join with the original table and match the "keys" (team, game and min) to get the other columns as well.
Note that if a team will have more than one member with the same value for max_minions then all these rows will be selected. If you only want one of them then that's probably a bit more complicated.