I have this table:
Name | Weight | Color
1 Cherry | 1 | Red
2 Apple | 4 | Green
3 Pear | 3 | Yellow
I need a view in which only the top row is visible
Cherry | 1 | Red
When the table changes (new record, sorting), the view changes accordingly
Example 1:
Name | Weight V| Color
1 Apple | 4 | Green
2 Pear | 3 | Yellow
3 Cherry | 1 | Red
single row view:
Apple | 4 | Green
Example 2:
Name | Weight | Color
1 Almond | 0.5 | Brown
2 Apple | 4 | Green
3 Pear | 3 | Yellow
4 Cherry | 1 | Red
single row view:
Almond | 0.5 | Brown
This doesn't seem possible. Didn't find anything in related forums.
GPT3 suggestions were selecting a record by row_id or time_of_creation fields, but this won't help with table resorting.
It also suggested using SELECT(table_name, {}, {limit: N, fields: ["field_1", "field_2"]}) - but limit does not work. Same for FIRST() which doesn't exist.
Any solution to this?
Try a record list. You can sort elements there as well as limit how many you want to list.
I guess the other would be scripting and just "limiting" what the query returns when displaying it (which doesn't sound like what you want). I am not sure there is a simple native way.
I guess in the end record list limits are the closest to what you are trying to achieve, especially since your main criterion for a top row is sorting.
Related
Is it possible to fuzzy match a substring within a larger string in Postgres?
Example:
For a search of colour (ou), return all records where the string includes color, colors or colour.
select
*
from things
where fuzzy(color) in description;
id | description
----------------
1 | A red coloured car
2 | The garden
3 | Painting colors
=> return records 1 and 3
I was wondering if it's possible to combine both fuzzystrmatch and tsvector so that the fuzzy matching could be applied to each vectorized term?
Or if there is another approach?
You can do it of course, but I doubt it will be very useful:
select *,levenshtein(lexeme,'color') from things, unnest(to_tsvector('english',description))
order by levenshtein;
id | description | lexeme | positions | weights | levenshtein
----+--------------------+--------+-----------+---------+-------------
3 | Painting colors | color | {2} | {D} | 0
1 | A red coloured car | colour | {3} | {D} | 1
1 | A red coloured car | car | {4} | {D} | 3
1 | A red coloured car | red | {2} | {D} | 5
3 | Painting colors | paint | {1} | {D} | 5
2 | The garden | garden | {2} | {D} | 6
Presumably you would want to embellish the query to apply some cutoff, probably where the cutoff depends on the lengths, and return only the best result for each description assuming it met that cutoff. Doing that should be just routine SQL manipulations.
Perhaps better would be the word similarity operators recently added to pg_trgm.
select *, description <->> 'color' as distance from things order by description <->> 'color';
id | description | distance
----+--------------------+----------
3 | Painting colors | 0.166667
1 | A red coloured car | 0.333333
2 | The garden | 1
Another option would be to find a stemmer or thesaurus which standardizes British/American spellings (I am not aware of one readily available), and then not use fuzzy matching at all. I think this would be best, if you can do it.
I am trying to define conditional formatting on a bar chart in excel based on the value of the data point or his legend.
I want to make it dynamic.
Let's suppose that I have the following chart
3 Alex
4 John
6 David
I want to color the bar ABOVE "John" in red.
Any ideas ?
Thanks
Jon Peltier has a great article showing how you can do this: https://peltiertech.com/conditional-formatting-of-excel-charts/
In essence, just use two different series with data like so:
| A | B | C |
-------------------
1 | Alex | 3 | |
2 | John | | 4 |
3 | David | 6 | |
So you plot a bar chart with 2 series, the first using column B and the second (red) using column C. If you have some rule that decides who should be red, then just use =IF() instead of hard coding the numbers
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I would like to have some help on the best way to address a specific revision. I have the following SQL query:
SELECT * FROM PRODDTA.F4105
WHERE (COITM, COMCU) IN ((`"Set of Data 1"`))
AND (COLOCN, COLEDG) NOT IN ((`"Set of Data 2"`));
What I want to do is to revise if there is someway to merge these items in one:
SELECT * FROM PRODDTA.F4105
WHERE (COITM, COMCU, COLOCN, COLEDG) IN ((`"Set of Data 1 & 2"`));
Do you know if this is achievable?
Thanks a lot in advance,
This really depends on where Set of data 1 and Set of data2 come from and what their relationship is to each other, and I'm pressed to imagine a real world scenario where this would be a good idea.
A Set of Data here is really just a set of Records with Fields. These Fields have, inherently, a relationship to one another which is why they are present on a single Record.
Issue 1: The two sets contain data that don't relate to each other:
Set of Data1 could be completely disparate from Set of Data2 and so there is no way to say that they can be combined.
Imagine two sets:
Set1:
+-------+--------+
| color | animal |
+-------+--------+
| brown | dog |
| white | dog |
| black | dog |
| green | parrot |
| green | turtle |
| brown | turtle |
+-------+--------+
Set2:
+------------+--------+
| food | flavor |
+------------+--------+
| pepper | spicy |
| water | |
| grapefruit | bitter |
| lemon | sour |
| candy | sweet |
+------------+--------+
A queries WHERE clause:
WHERE (f1, f2) IN (SELECT color, animal FROM set1)
AND (f3, f4) IN (SELECT food, flavor FROM set2)
There's no good way to write this where we test (f1, f2, f3, f4) as there is no relationship between color | animal and food | flavor.
We could, if we were in crazytown, cross join the two sets to get their cartesian product yielding the same result set as the original query:
WHERE (f1, f2, f3, f4) IN (SELECT color, animal, food, flavor FROM set1, set2)
But now we have a subquery with an intermediate result set of set1 x set2 number of records. This is dumb for multiple reasons:
Indexes on the two sets are ignored
If set1 or set2 are more than a few records, you end up with a HUGE intermediate result set.
There is no relationship between these two sets, so it's crazy town to combine them just to make your SQL less characters.
There will be huge amounts of unnecessary system resources (CPU, Disk, I/O) used to build and store this intermediate result set resulting in a cumbersome slow query.
Any other developer upon seeing it will hunt you down and kill you. If they call me up, I'll provide the getaway car.
Issue 2: The two sets could have a relationship with one another, but changing your IN conditions into 1 causes records to drop.
Even if the two sets can be combined, you may still end up with results that differ from the original query. Imagine:
Set1:
+-------+--------+
| color | animal |
+-------+--------+
| brown | dog |
| white | dog |
| black | dog |
| green | parrot |
| green | turtle |
| brown | turtle |
+-------+--------+
Set 2:
+--------+-------------+
| animal | stink_scale |
+--------+-------------+
| turtle | 2 |
| parrot | 4 |
| dog | 5 |
| skunk | 10 |
+--------+-------------+
Table1:
+-------+--------+---------+-------------+
| color | animal | animal2 | stink_scale |
+-------+--------+---------+-------------+
| white | dog | dog | 5 |
| brown | dog | parrot | 4 |
| green | turtle | turtle | 2 |
+-------+--------+---------+-------------+
The query you want to change:
SELECT * FROM table1
WHERE (color, animal) IN (SELECT color, animal FROM Set1)
AND (animal2, stink_scale) IN (SELECT animal, stink_scale FROM set2);
This would yield 3 records as white | dog is in set1 and dog | 5 is in set as it brown | dog in set1 and parrot | 4 is in set2 and the same for the third record in table1.
BUT if we combine these two sets on their animal key:
SELECT set1.color, set1.animal, set2.animal as animal2, set2.stink_scale FROM set1 JOIN set2 ON set1.animal = set2.animal;
We will get the set:
+-------+--------+---------+-------------+
| color | animal | animal2 | stink_scale |
+-------+--------+---------+-------------+
| brown | dog | dog | 5 |
| white | dog | dog | 5 |
| black | dog | dog | 5 |
| green | parrot | parrot | 4 |
| green | turtle | turtle | 2 |
| brown | turtle | turtle | 2 |
+-------+--------+---------+-------------+
And we use that to combine our IN conditions:
SELECT *
FROM table1
WHERE (color, animal, animal2, stink_scale) IN (SELECT set1.color, set1.animal, set2.animal as animal2, set2.stink_scale FROM set1 JOIN set2 ON set1.animal = set2.animal)
We only get 2 records back since there is no result in that subquery where brown | dog | parrot | 4 will exist.
So, in the end unless there is a reason to change the conditions, thus changing the definition of the result set, you probably best off leaving it alone. It really changes the logic.
I want to pull, say, all rows where a User has Color=blue and Color=red. I am interested in pulling these multiple rows to determine which users CHANGED their Color from blue to red, or from red to blue.
The general query i have now is this. What is wrong and how can i improve it? thank you!
Does this return Zero results because I am asking that the row's value has BOTH blue and red at the same time? (which is impossible)
my other worry, is that if I use OR instead of AND, that i will include rows for users that are color blue, or color red, but did NOT change between the two colors.
I want the results to ONLY show rows 1 and 4
SELECT *
FROM Table a
WHERE a.color='blue'
AND a.color='red'
Table Structure is below
Row | Date | Userid | Session | Color
1 | 11/1 | 001 | 24 | Blue
2 | 11/2 | 002 | 25 | Green
3 | 11/2 | 003 | 26 | Yellow
4 | 11/6 | 001 | 32 | Red
The glaring problem is:
SELECT *
FROM Table a
WHERE a.color='Blue'
OR a.color='Red'
You will either need a field with the previous color to be stored (kind of like a history) if you wish because otherwise there's not enough information in the database to properly assess what colors have been changed from.
Disclaimers first: I'm dealing with a legacy database with a pretty bizarre schema. Plus, I'm a complete SQL noob, so that's not helping either.
Basically, I have a table that has product variations. A good example might be t-shirts. The "generic" t-shirt has a product id. Each type of variation (size, color) has an id. Each value of the variation (red, small) has an id.
So table looks like:
+----+----------+-----------+-------------+----------+------------+
| id | tshirt | option_id | option_name | value_id | value_name |
+----+----------+-----------+-------------+----------+------------+
| 1 | Zombies! | 2 | color | 13 | red |
| 1 | Zombies! | 2 | color | 24 | black |
| 1 | Zombies! | 3 | size | 35 | small |
| 1 | Zombies! | 3 | size | 36 | medium |
| 1 | Zombies! | 3 | size | 56 | large |
| 2 | Ninja! | 2 | color | 24 | black |
| 2 | Ninja! | 3 | size | 35 | small |
+----+----------+-----------+-------------+----------+------------+
I want to write a query that retrieves the different combinations for a given product.
In this example, the Zombie shirt comes in Red/Small, Red/Medium, Red/Large, Black/Small, Black/Medium, and Black/Large (six variations). The Ninja shirt just has the one variation: Black/Small.
I believe this is the cartesian product of size and color.
Those ids are really foreign keys to other tables, so those names/values aren't but wanted to include for clarity.
The number of options can vary (not limited to two) and the number of values per option can vary as well. Ultimately, the numbers are likely to small-ish for a given product so I'm not worried about millions of rows here.
Any ideas on how I might do this?
Thanks,
p.
try this:
select
f.id,
f.tshirt,
color.option_id as color_option_id,
color.option_name as color_option_name,
color.value_id as color_value_id,
color.value_name as color_value_name,
size.option_id as size_option_id,
size.option_name as size_option_name,
size.value_id as size_value_id,
size.value_name as size_value_name
from
foo f
inner join foo color on f.id = color.id and f.value_id = color.value_id and color.option_id = 2
inner join foo size on f.id = size.id and size.option_id = 3
order by
f.id,
color.option_id, color.value_id,
size.value_id, size.value_id;
Looks like distinct can do the trick:
select distinct tshirt
, option_name
, value_name
from YourTable