Cursor not populating while using max in sqlite
I have a database like following
datetime value
date1 200
date2 230
date3 210
date4 240
date5 220
I find out the rowid for the column of which I want to dynamically find out the max value for the 2 rows above
Say I found 4 for date4, I want to calculate the maximum of values 230,210 and 240 which is 240
I give the following command
c.execute("SELECT MAX(value) FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
The problem is cursor doesn't populate and returns an empty list while in
c.execute("SELECT value FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
it returns the correct values of the 3 rows (3 tuples in a list). Can I not use limit with max? What is the problem? Do I have to make another int column equivalent to rowid for querying well and use an order by numberingColumn or is there a better solution?
python sqlite sqlite3
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
add a comment |
I have a database like following
datetime value
date1 200
date2 230
date3 210
date4 240
date5 220
I find out the rowid for the column of which I want to dynamically find out the max value for the 2 rows above
Say I found 4 for date4, I want to calculate the maximum of values 230,210 and 240 which is 240
I give the following command
c.execute("SELECT MAX(value) FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
The problem is cursor doesn't populate and returns an empty list while in
c.execute("SELECT value FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
it returns the correct values of the 3 rows (3 tuples in a list). Can I not use limit with max? What is the problem? Do I have to make another int column equivalent to rowid for querying well and use an order by numberingColumn or is there a better solution?
python sqlite sqlite3
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
1
Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44
add a comment |
I have a database like following
datetime value
date1 200
date2 230
date3 210
date4 240
date5 220
I find out the rowid for the column of which I want to dynamically find out the max value for the 2 rows above
Say I found 4 for date4, I want to calculate the maximum of values 230,210 and 240 which is 240
I give the following command
c.execute("SELECT MAX(value) FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
The problem is cursor doesn't populate and returns an empty list while in
c.execute("SELECT value FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
it returns the correct values of the 3 rows (3 tuples in a list). Can I not use limit with max? What is the problem? Do I have to make another int column equivalent to rowid for querying well and use an order by numberingColumn or is there a better solution?
python sqlite sqlite3
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
I have a database like following
datetime value
date1 200
date2 230
date3 210
date4 240
date5 220
I find out the rowid for the column of which I want to dynamically find out the max value for the 2 rows above
Say I found 4 for date4, I want to calculate the maximum of values 230,210 and 240 which is 240
I give the following command
c.execute("SELECT MAX(value) FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
The problem is cursor doesn't populate and returns an empty list while in
c.execute("SELECT value FROM TABLE LIMIT "+str(rowid-2)+",3")
print(c.fetchall())
it returns the correct values of the 3 rows (3 tuples in a list). Can I not use limit with max? What is the problem? Do I have to make another int column equivalent to rowid for querying well and use an order by numberingColumn or is there a better solution?
python sqlite sqlite3
python sqlite sqlite3
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
asked Nov 13 '18 at 20:57
caissalovercaissalover
239
239
1
Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44
add a comment |
1
Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44
1
1
Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44
Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44
add a comment |
1 Answer
1
active
oldest
votes
Thank you @Shawn
c.execute("SELECT MAX(TEMPVALUE) FROM (SELECT value AS TEMPVALUE FROM TABLE LIMIT "+str(rowid+2)+",3)")
solved the problem!
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
add a comment |
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Thank you @Shawn
c.execute("SELECT MAX(TEMPVALUE) FROM (SELECT value AS TEMPVALUE FROM TABLE LIMIT "+str(rowid+2)+",3)")
solved the problem!
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
add a comment |
Thank you @Shawn
c.execute("SELECT MAX(TEMPVALUE) FROM (SELECT value AS TEMPVALUE FROM TABLE LIMIT "+str(rowid+2)+",3)")
solved the problem!
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
add a comment |
Thank you @Shawn
c.execute("SELECT MAX(TEMPVALUE) FROM (SELECT value AS TEMPVALUE FROM TABLE LIMIT "+str(rowid+2)+",3)")
solved the problem!
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
Thank you @Shawn
c.execute("SELECT MAX(TEMPVALUE) FROM (SELECT value AS TEMPVALUE FROM TABLE LIMIT "+str(rowid+2)+",3)")
solved the problem!
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
answered Nov 14 '18 at 10:30
caissalovercaissalover
239
239
add a comment |
add a comment |
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Your first query returns a single row, which you say to skip with that offset of 3. Thus, no rows are returned.
– Shawn
Nov 13 '18 at 21:44