Is it possible to output a resultset as a grid? For example I output the following resultset using sql:
col1 col2 col3 col4 col5 col6 col7 col8 col9
10 23 54 12 23 45 56 24 2
but instead of the output forming one long row is there a function I can use to get it to output as:
col1 col2 col3
10 23 54
12 23 45
56 24 2
So I'm essentially breaking the results row every three columns.
Also the output would be a combinations of various calculations performed on the data in joined sql tables just in case this makes a difference.
If you don't mind manually defining the columns to split, and the format will remain fixed you can use CROSS APPLY ... VALUES to unpivot the data. e.g.
SELECT c.Col1, c.Col2, c.Col3
FROM T
CROSS APPLY
( VALUES
(Col1, Col2, Col3),
(Col4, Col5, Col6),
(Col7, Col8, Col9)
) c (Col1, Col2, Col3);
Example on SQL Fiddle
Related
I have a table in a Postgres that stores 10x10 matrices, where each row has it's own entry, defined as:
id, matrix_id, row_id, col1, col2, col3...
I'd like to compute the trace (sum of main diagonal) for every matrix identified by its matrix_id, that is, for every matrix_id, I would like to get (col1 where row_id=1) + (col2 where row_id=2) + (col3 where row_id=3)...
I've tried grouping it by matrix_id but then I cannot use subqueries, something like:
select matrix_id, (select col1 where row_id=1) + (col2 where row_id=2) +
(col3 where row_id=3) ... from matrix group by matrix_id;
but it doesn't work this way.
How could I do that?
So long as they are all 10x10 matrices, use a case statement like so:
select matrix_id,
sum(
case row_id
when 1 then col1
when 2 then col2
when 3 then col3
when 4 then col4
when 5 then col5
when 6 then col6
when 7 then col7
when 8 then col8
when 9 then col9
when 10 then col10
end
) as trace
from matrix
group by matrix_id;
Had variable-sized matrices been allowed, you could transpose columns to rows via to_jsonb() and then sum where row_id = <column suffix>.
EDIT TO ADD
Based on your comment, you really should update your version of PostgreSQL. That said, try a CTE to filter on the new trace column:
with traces as (
select matrix_id,
sum(
case row_id
when 1 then col1
when 2 then col2
when 3 then col3
when 4 then col4
when 5 then col5
when 6 then col6
when 7 then col7
when 8 then col8
when 9 then col9
when 10 then col10
end
) as trace
from matrix
group by matrix_id
)
select *
from traces
where trace > 100;
I've put together a reconciliation tool in SQL Server which identifies the number of record breaks by field (col 2 - col 4) between two identical (data types/structure) sources. The output returned is in the format below, grouped on col 1.
Col1 Col2 Col3 Col4
X 0 0 1
Y 0 1 1
Z 1 0 1
I am trying to manipulate the output so that it provides a list of the Col 1 identifier and the name of any column names (col 2 - col 4) which have breaks (value > 0).
The expected output based on the above data would look like this.
Col1 FieldBreak
X Col2
Y Col3
Y Col4
Z Col2
Z Col4
I'm newer to SQL (6 months of professional experience) and am stuck. Any help would be much appreciated!
In any database, you can use:
select col1, 'col2' as col
from t
where col2 = 1
union all
select col1, 'col3' as col
from t
where col3 = 1
union all
select col1, 'col4' as col
from t
where col4 = 1;
There are probably more efficient methods, but those depend on the database. And for a small table efficiency may not be a concern.
In SQL Server, you would unpivot using apply:
select t.col1, v.*
from t cross apply
(values ('col2', t.col2), ('col3', t.col3) . . .
) v(col, val)
where v.val is not null;
If you have a lot of columns, you can construct the expression using a SQL statement (from INFORMATION_SCHEMA.COLUMNS) and/or using a spreadsheet.
I have a table like this one
ID Col1 Col2 Col3
-- ---- ---- ----
1 7 NULL 12
2 2 46 NULL
3 NULL NULL NULL
4 245 1 792
I wanted a query that yields the following result
ID Col1 Col2 Col3 MIN
-- ---- ---- ---- ---
1 7 NULL 12 7
2 2 46 NULL 2
3 NULL NULL NULL NULL
4 245 1 792 1
I mean, I wanted a column containing the minimum values out of Col1, Col2, and Col 3 for each row ignoring NULL values. In a previous question (What's the best way to select the minimum value from multiple columns?) there is an answer for non NULL values. I need a query as efficient as possible for a huge table.
Select Id,
Case When Col1 < Col2 And Col1 < Col3 Then Col1
When Col2 < Col1 And Col2 < Col3 Then Col2
Else Col3
End As MIN
From YourTableNameHere
Assuming you can define some "max" value (I'll use 9999 here) that your real values will never exceed:
Select Id,
Case When Col1 < COALESCE(Col2, 9999)
And Col1 < COALESCE(Col3, 9999) Then Col1
When Col2 < COALESCE(Col1, 9999)
And Col2 < COALESCE(Col3, 9999) Then Col2
Else Col3
End As MIN
From YourTableNameHere;
You didn't specify which version of Teradata you're using. If you're using version 14+ then you can use least.
Unfortunately least will return null if any of its arguments are null. From the docs:
LEAST supports 1-10 numeric values.
If numeric_value is the data type of the first argument, the return
data type is numeric. The remaining arguments in the input list must
be the same or compatible types. If either input parameter is NULL,
NULL is returned.
But you can get around that by using coalesce as Joe did in his answer.
select id,
least(coalesce(col1,9999),coalesce(col2,9999),coalesce(col3,9999))
from mytable
This might work:
Select id, Col1, Col2, Col3, least(Col1, Col2, Col3) as MIN From YourTableNameHere
in this way you don't need to check for nulls, just use min and a subquery
select tbl.id,tbl.col1,tbl.col2,tbl.col3,
(select min(t.col)
from (
select col1 as col from tbl_name t where t.id=tbl.id
union all
select col2 as col from tbl_name t where t.id=tbl.id
union all
select col3 as col from tbl_name t where t.id=tbl.id
)t)
from tbl_name tbl
Output:
1 7 NULL 12 7
2 2 46 NULL 2
3 NULL NULL NULL NULL
4 245 1 792 1
Just modify your query with coalesce():
Select Id,
(Case When Col1 <= coalesce(Col2, col3, col1) And
Col1 <= coalesce(Col3, col2, col1)
Then Col1
When Col2 <= coalesce(Col1, col3, col2) And
Col2 <= coalesce(Col3, col1, col2)
Then Col2
Else Col3
End) As MIN
From YourTableNameHere;
This doesn't require inventing a "magic" number or over-complicating the logic.
I found this solution to be more efficient than using multiple case statement clauses, which can get extremely lengthy when evaluating data from several columns across one row.
Also, I can't take credit for this solution as I found it on some website a year or so ago. Today I needed a refresh on this logic, and I couldn't find it anywhere. I found my old code and decided to share it in this forum now.
Creating your test table:
create table #testTable(ID int, Col1 int, Col2 int, Col3 int)
Insert into #testTable values(1,7,null,12)
Insert into #testTable values(2,2,46,null)
Insert into #testTable values(3,null,null,null)
Insert into #testTable values(4,245,1,792)
Finding min value in row data:
Select ID, Col1, Col2, Col3 ,(SELECT Min(v) FROM ( VALUES (Col1), (Col2), (Col3) ) AS value(v)) [MIN] from #testTable order by ID
You might not understood what I want to ask from the title but ,here is the explanation.
I have a data in Oracle database table. What I wanted to do is insert a new data to the table. This new data is based on the existing data but I have to change the value of one columns. So if I have 10 rows in the database after the insertion i will have 20 rows but the new 10 rows contain the same data except on of the columns is changed.
E.g table before insertion a new data
Col1 Col2 Col3
a b AA
1 2 33
table after insertion a new data
Col1 Col2 Col3
a b **BB**
1 2 **44**
Provided that you can encode what the new value should be; yes.
INSERT INTO
myTable (
Col1,
Col2,
Col3
)
SELECT
Col1,
Col2, -- This is a specific example based on your comment.
Col3 + 6 -- This just adds 6 to the existing value, but any SQL
FROM -- could actually go here, such as a CASE statement...
myTable
So, the question becomes; Do you have rules that you can implement in SQL for calculating the new value for Col3?
The rules could be something basic like...
CASE WHEN Col3 = 'AA' THEN '**BB**'
WHEN Col3 = '33' THEN '**44**'
ELSE 'Unknown'
END,
Or you could have all the new values in another table and look them up using a join...
INSERT INTO
myTable (
Col1,
Col2,
Col3
)
SELECT
OldTable.Col1,
OldTable.Col2,
COALESCE(NewTable.Col3, 'Unknown')
FROM
myTable AS OldTable
LEFT JOIN
lookup AS NewTable
ON OldTable.Col1 = NewTable.Col1
AND OldTable.Col2 = NewTable.Col2
Or a whole bunch of other options.
It will depend on how you determine how to change the data. How do you know, for example, that AA should become BB or that 33 should become 44?
Something like this will work for the two cases you posted. You can adapt it to whatever rule you want by changing the CASE statement to compute the new value differently.
INSERT INTO table_name( col1, col2, col3 )
SELECT col1,
col2,
(CASE WHEN col3 = 'AA'
THEN 'BB'
WHEN col3 = '33'
THEN '44'
ELSE null
END)
FROM table_name;
Let's say I had two columns in a database, col1 and col2. Column 2 is the time, Column 1 something. In my query, I want to do the following:
I want to SELECT * from my table and group the results by col1. However, I only want those entries where for the grouped col1 there is no value of col2 higher than a certain value. Meaning that, I only want those col1-s for which col2 does not exceed a certain value.
If, for instance, I had three rows, as follows:
ROW1: col1 = val1, col2 = 3
ROW2: col1 = val1, col2 = 5
ROW3: col1 = val2, col2 = 3
ROW4: col1 = val2, col2 = 4
And I do not want the time for any of them to exceed 4, then, as a result, I would only want ROW3 or ROW4, which, does not matter, for col1 is the same and is grouped. But in rows 1 and 2, that are grouped by col1's value "val1", in one of them col2 DOES exceed 4, therefore, I do not want any of them.
SELECT col1 FROM table GROUP BY col1 HAVING MAX(col2) <= 4
Because you want only the common value (col1) from the group, you can use GROUP BY. When you do a GROUP BY (aggregate) query, you can use the HAVING clause to apply a filter to the aggregated data set.
I am not use I got the point (my english is not good).
I think sub-query is the best choice.
Note: this example should work with mySql ...
SELECT *
FROM table
WHERE col1 IN
(SELECT col1 FROM table WHERE col2 < 5 GROUP BY col1)
ORDER BY col1
CREATE TABLE x (
t TIME NOT NULL,
v INT NOT NULL );
INSERT INTO x VALUES
('13:14:00', 24),
('13:14:00', 27),
('13:14:00', 29),
('17:12:00', 14),
('17:12:00', 20),
('17:12:00', 24);
SELECT t, MAX(v) AS mv FROM x
GROUP BY t
HAVING mv <= 25;
Or do I misunderstand the question?