Regex left join in KDB
In KDB, is it possible to perform a lj (Left-Join) using "like" or "~" to join 2 tables where 1 table's key matches another tables's key by regex?
kdb
asked Nov 14 '18 at 6:35
delitadelita
83211018
add a comment |
In KDB, is it possible to perform a lj (Left-Join) using "like" or "~" to join 2 tables where 1 table's key matches another tables's key by regex?
kdb
asked Nov 14 '18 at 6:35
delitadelita
83211018
Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39
add a comment |
In KDB, is it possible to perform a lj (Left-Join) using "like" or "~" to join 2 tables where 1 table's key matches another tables's key by regex?
kdb
asked Nov 14 '18 at 6:35
delitadelita
83211018
In KDB, is it possible to perform a lj (Left-Join) using "like" or "~" to join 2 tables where 1 table's key matches another tables's key by regex?
kdb
kdb
asked Nov 14 '18 at 6:35
delitadelita
83211018
asked Nov 14 '18 at 6:35
delitadelita
83211018
asked Nov 14 '18 at 6:35
delitadelita
83211018
asked Nov 14 '18 at 6:35
delitadelita
83211018
asked Nov 14 '18 at 6:35
delitadelita
83211018
83211018
Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39
add a comment |
Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39
Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39
add a comment |
1 Answer
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Not using out-of-the-box tools, but you could do something like this (won't be incredibly efficient)
q)t:(sym:`ACF`ABC`ABD`BA`AAF`AABG`CDE;col1:til 7)
q)t2:(regex:("*AB*";"AA?";"A*";"C*");col2:4#.Q.A)
q)t,'t2 first each where each t[`sym]like':t2[`regex]
sym col1 regex col2
---------------------
ACF 0 "A*" C
ABC 1 "*AB*" A
ABD 2 "*AB*" A
BA 3 ""
AAF 4 "AA?" B
AABG 5 "*AB*" A
CDE 6 "C*" D
This approach would take the first matched pattern if there's more than one match.
Another idea is to create a manufactured key and left join on the manufactured key.
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Not using out-of-the-box tools, but you could do something like this (won't be incredibly efficient)
q)t:(sym:`ACF`ABC`ABD`BA`AAF`AABG`CDE;col1:til 7)
q)t2:(regex:("*AB*";"AA?";"A*";"C*");col2:4#.Q.A)
q)t,'t2 first each where each t[`sym]like':t2[`regex]
sym col1 regex col2
---------------------
ACF 0 "A*" C
ABC 1 "*AB*" A
ABD 2 "*AB*" A
BA 3 ""
AAF 4 "AA?" B
AABG 5 "*AB*" A
CDE 6 "C*" D
This approach would take the first matched pattern if there's more than one match.
Another idea is to create a manufactured key and left join on the manufactured key.
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
add a comment |
Not using out-of-the-box tools, but you could do something like this (won't be incredibly efficient)
q)t:(sym:`ACF`ABC`ABD`BA`AAF`AABG`CDE;col1:til 7)
q)t2:(regex:("*AB*";"AA?";"A*";"C*");col2:4#.Q.A)
q)t,'t2 first each where each t[`sym]like':t2[`regex]
sym col1 regex col2
---------------------
ACF 0 "A*" C
ABC 1 "*AB*" A
ABD 2 "*AB*" A
BA 3 ""
AAF 4 "AA?" B
AABG 5 "*AB*" A
CDE 6 "C*" D
This approach would take the first matched pattern if there's more than one match.
Another idea is to create a manufactured key and left join on the manufactured key.
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
add a comment |
Not using out-of-the-box tools, but you could do something like this (won't be incredibly efficient)
q)t:(sym:`ACF`ABC`ABD`BA`AAF`AABG`CDE;col1:til 7)
q)t2:(regex:("*AB*";"AA?";"A*";"C*");col2:4#.Q.A)
q)t,'t2 first each where each t[`sym]like':t2[`regex]
sym col1 regex col2
---------------------
ACF 0 "A*" C
ABC 1 "*AB*" A
ABD 2 "*AB*" A
BA 3 ""
AAF 4 "AA?" B
AABG 5 "*AB*" A
CDE 6 "C*" D
This approach would take the first matched pattern if there's more than one match.
Another idea is to create a manufactured key and left join on the manufactured key.
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
Not using out-of-the-box tools, but you could do something like this (won't be incredibly efficient)
q)t:(sym:`ACF`ABC`ABD`BA`AAF`AABG`CDE;col1:til 7)
q)t2:(regex:("*AB*";"AA?";"A*";"C*");col2:4#.Q.A)
q)t,'t2 first each where each t[`sym]like':t2[`regex]
sym col1 regex col2
---------------------
ACF 0 "A*" C
ABC 1 "*AB*" A
ABD 2 "*AB*" A
BA 3 ""
AAF 4 "AA?" B
AABG 5 "*AB*" A
CDE 6 "C*" D
This approach would take the first matched pattern if there's more than one match.
Another idea is to create a manufactured key and left join on the manufactured key.
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
edited Nov 15 '18 at 13:59
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,284517
4,284517
add a comment |
add a comment |
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Hi delita, would you be able to give an example of the tables you are working with and what the desired output should look like?
– C.Ross
Nov 14 '18 at 14:14
please mark the answer as the accepted answer if you find it so
– terrylynch
Dec 6 '18 at 18:39