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
1
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
4,204517
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53294376%2fregex-left-join-in-kdb%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
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
4,204517
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
4,204517
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
4,204517
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
4,204517
edited Nov 15 '18 at 13:59
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,204517
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,204517
answered Nov 14 '18 at 14:19
terrylynchterrylynch
4,204517
4,204517
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53294376%2fregex-left-join-in-kdb%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
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