Is there a way to get max function to ignore nulls within a column in sqlite?
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Simply put, if I have a table with two columns (say people and height), I can use select max(height) from 'table' group by people and it will yield the largest height for any group of people_ignoring any nulls_.
If, however, I have a table with more columns (height_1, height_2, height_3, etc.) and I want to simply reproduce that table with a new column showing the maximum height (height_1, height_2, height_3, max_height), I would intuitvely like to put.
select
height_1,
height_2,
height_3,
max(height_1, height_2, height_3) as max_height
from 'table'
but used this way, max seems to behave differently, returning null if any of the arguments are null.
Is there some form of use which will get it to behave the way it does when aggregating a column, and ignore null values?, even when aggregating single values across a range of columns?
sqlite
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
asked Nov 12 at 7:05
Isaacson
946
add a comment |
up vote
0
down vote
favorite
Simply put, if I have a table with two columns (say people and height), I can use select max(height) from 'table' group by people and it will yield the largest height for any group of people_ignoring any nulls_.
If, however, I have a table with more columns (height_1, height_2, height_3, etc.) and I want to simply reproduce that table with a new column showing the maximum height (height_1, height_2, height_3, max_height), I would intuitvely like to put.
select
height_1,
height_2,
height_3,
max(height_1, height_2, height_3) as max_height
from 'table'
but used this way, max seems to behave differently, returning null if any of the arguments are null.
Is there some form of use which will get it to behave the way it does when aggregating a column, and ignore null values?, even when aggregating single values across a range of columns?
sqlite
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
asked Nov 12 at 7:05
Isaacson
946
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
Simply put, if I have a table with two columns (say people and height), I can use select max(height) from 'table' group by people and it will yield the largest height for any group of people_ignoring any nulls_.
If, however, I have a table with more columns (height_1, height_2, height_3, etc.) and I want to simply reproduce that table with a new column showing the maximum height (height_1, height_2, height_3, max_height), I would intuitvely like to put.
select
height_1,
height_2,
height_3,
max(height_1, height_2, height_3) as max_height
from 'table'
but used this way, max seems to behave differently, returning null if any of the arguments are null.
Is there some form of use which will get it to behave the way it does when aggregating a column, and ignore null values?, even when aggregating single values across a range of columns?
sqlite
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
asked Nov 12 at 7:05
Isaacson
946
Simply put, if I have a table with two columns (say people and height), I can use select max(height) from 'table' group by people and it will yield the largest height for any group of people_ignoring any nulls_.
If, however, I have a table with more columns (height_1, height_2, height_3, etc.) and I want to simply reproduce that table with a new column showing the maximum height (height_1, height_2, height_3, max_height), I would intuitvely like to put.
select
height_1,
height_2,
height_3,
max(height_1, height_2, height_3) as max_height
from 'table'
but used this way, max seems to behave differently, returning null if any of the arguments are null.
Is there some form of use which will get it to behave the way it does when aggregating a column, and ignore null values?, even when aggregating single values across a range of columns?
sqlite
sqlite
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
asked Nov 12 at 7:05
Isaacson
946
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
asked Nov 12 at 7:05
Isaacson
946
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
edited Nov 12 at 7:11
a_horse_with_no_name
290k46442537
290k46442537
asked Nov 12 at 7:05
Isaacson
946
asked Nov 12 at 7:05
Isaacson
946
asked Nov 12 at 7:05
Isaacson
946
946
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
1
down vote
accepted
You can use something like:
SELECT height_1
, height_2
, height_3
, max(ifnull(height_1, 0), ifnull(height_2, 0), ifnull(height_3, 0)) AS max_height
FROM "table"
answered Nov 12 at 7:29
Shawn
3,4531613
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
@Isaacson Just use a larger-than-possible number formin(), and a smaller-than-possible one formax()(And check if your select returned that number to handle cases of all values being null).
– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
add a comment |
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1 Answer
1
active
oldest
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
accepted
You can use something like:
SELECT height_1
, height_2
, height_3
, max(ifnull(height_1, 0), ifnull(height_2, 0), ifnull(height_3, 0)) AS max_height
FROM "table"
answered Nov 12 at 7:29
Shawn
3,4531613
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
@Isaacson Just use a larger-than-possible number formin(), and a smaller-than-possible one formax()(And check if your select returned that number to handle cases of all values being null).
– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
add a comment |
up vote
1
down vote
accepted
You can use something like:
SELECT height_1
, height_2
, height_3
, max(ifnull(height_1, 0), ifnull(height_2, 0), ifnull(height_3, 0)) AS max_height
FROM "table"
answered Nov 12 at 7:29
Shawn
3,4531613
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
@Isaacson Just use a larger-than-possible number formin(), and a smaller-than-possible one formax()(And check if your select returned that number to handle cases of all values being null).
– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
add a comment |
up vote
1
down vote
accepted
up vote
1
down vote
accepted
You can use something like:
SELECT height_1
, height_2
, height_3
, max(ifnull(height_1, 0), ifnull(height_2, 0), ifnull(height_3, 0)) AS max_height
FROM "table"
answered Nov 12 at 7:29
Shawn
3,4531613
You can use something like:
SELECT height_1
, height_2
, height_3
, max(ifnull(height_1, 0), ifnull(height_2, 0), ifnull(height_3, 0)) AS max_height
FROM "table"
answered Nov 12 at 7:29
Shawn
3,4531613
answered Nov 12 at 7:29
Shawn
3,4531613
answered Nov 12 at 7:29
Shawn
3,4531613
answered Nov 12 at 7:29
Shawn
3,4531613
3,4531613
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
@Isaacson Just use a larger-than-possible number formin(), and a smaller-than-possible one formax()(And check if your select returned that number to handle cases of all values being null).
– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
add a comment |
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
@Isaacson Just use a larger-than-possible number formin(), and a smaller-than-possible one formax()(And check if your select returned that number to handle cases of all values being null).
– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
Thanks. Follow up question, is there a way to do the same with min()? the problem here being that replacing nulls with '0' would give a false impression from the set 2,4,null,5,null,7 that the minimum was 0 when in fact the minimum non-null value is 2.
– Isaacson
Nov 12 at 7:51
1
1
@Isaacson Just use a larger-than-possible number for
min(), and a smaller-than-possible one for max() (And check if your select returned that number to handle cases of all values being null).– Shawn
Nov 12 at 8:05
@Isaacson Just use a larger-than-possible number for
min(), and a smaller-than-possible one for max() (And check if your select returned that number to handle cases of all values being null).– Shawn
Nov 12 at 8:05
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
That's perfect, thanks.
– Isaacson
Nov 12 at 8:10
add a comment |
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