create a dictionary of list from an array of pocos?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box;
}
-2
Want to create a dictionary<string, list<string>>
from a result set that has a list of:
class catalog{
public string Name { get; set; }
public string CategoryName { get; set; }
public bool CategoryDeleted { get; set; }
}
I want the key to be the CategoryName and the value to be a List of Names.
Each Categories can have the same Name associated with it. One categoryname to many reportnames and it looks like this.
{Name = "rp1", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp3", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp1", CategoryName=cat2, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat2, CategoryDeleted = 0 }
I'd like a clean linq query that does this concisely.
what I have so far:
var dic = new Dictionary<string, List<string>>();
catalog.Select(x => x.CategoryName).Distinct().ToList().ForEach(x =>
{
dic.Add(x, catalog.Where(t => t.CategoryName == x).Select(t => t.ReportName).ToList());
});
I want to know if I can improve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
thanks!
c# linq dictionary
asked Nov 21 '18 at 22:13
melmackmelmack
406
add a comment |
-2
Want to create a dictionary<string, list<string>>
from a result set that has a list of:
class catalog{
public string Name { get; set; }
public string CategoryName { get; set; }
public bool CategoryDeleted { get; set; }
}
I want the key to be the CategoryName and the value to be a List of Names.
Each Categories can have the same Name associated with it. One categoryname to many reportnames and it looks like this.
{Name = "rp1", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp3", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp1", CategoryName=cat2, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat2, CategoryDeleted = 0 }
I'd like a clean linq query that does this concisely.
what I have so far:
var dic = new Dictionary<string, List<string>>();
catalog.Select(x => x.CategoryName).Distinct().ToList().ForEach(x =>
{
dic.Add(x, catalog.Where(t => t.CategoryName == x).Select(t => t.ReportName).ToList());
});
I want to know if I can improve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
thanks!
c# linq dictionary
asked Nov 21 '18 at 22:13
melmackmelmack
406
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
2
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
1
Don't you rather need a lookup?items.ToLookup(c => c.CategoryName, c => c.Name)
– Antonín Lejsek
Nov 22 '18 at 2:17
add a comment |
-2
-2
-2
Want to create a dictionary<string, list<string>>
from a result set that has a list of:
class catalog{
public string Name { get; set; }
public string CategoryName { get; set; }
public bool CategoryDeleted { get; set; }
}
I want the key to be the CategoryName and the value to be a List of Names.
Each Categories can have the same Name associated with it. One categoryname to many reportnames and it looks like this.
{Name = "rp1", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp3", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp1", CategoryName=cat2, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat2, CategoryDeleted = 0 }
I'd like a clean linq query that does this concisely.
what I have so far:
var dic = new Dictionary<string, List<string>>();
catalog.Select(x => x.CategoryName).Distinct().ToList().ForEach(x =>
{
dic.Add(x, catalog.Where(t => t.CategoryName == x).Select(t => t.ReportName).ToList());
});
I want to know if I can improve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
thanks!
c# linq dictionary
asked Nov 21 '18 at 22:13
melmackmelmack
406
Want to create a dictionary<string, list<string>>
from a result set that has a list of:
class catalog{
public string Name { get; set; }
public string CategoryName { get; set; }
public bool CategoryDeleted { get; set; }
}
I want the key to be the CategoryName and the value to be a List of Names.
Each Categories can have the same Name associated with it. One categoryname to many reportnames and it looks like this.
{Name = "rp1", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp3", CategoryName=cat1, CategoryDeleted = 0 }
{Name = "rp1", CategoryName=cat2, CategoryDeleted = 0 }
{Name = "rp2", CategoryName=cat2, CategoryDeleted = 0 }
I'd like a clean linq query that does this concisely.
what I have so far:
var dic = new Dictionary<string, List<string>>();
catalog.Select(x => x.CategoryName).Distinct().ToList().ForEach(x =>
{
dic.Add(x, catalog.Where(t => t.CategoryName == x).Select(t => t.ReportName).ToList());
});
I want to know if I can improve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
thanks!
c# linq dictionary
c# linq dictionary
asked Nov 21 '18 at 22:13
melmackmelmack
406
asked Nov 21 '18 at 22:13
melmackmelmack
406
edited Nov 21 '18 at 22:20
melmack
asked Nov 21 '18 at 22:13
melmackmelmack
406
asked Nov 21 '18 at 22:13
melmackmelmack
406
asked Nov 21 '18 at 22:13
melmackmelmack
406
406
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
2
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
1
Don't you rather need a lookup?items.ToLookup(c => c.CategoryName, c => c.Name)
– Antonín Lejsek
Nov 22 '18 at 2:17
add a comment |
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
2
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
1
Don't you rather need a lookup?items.ToLookup(c => c.CategoryName, c => c.Name)
– Antonín Lejsek
Nov 22 '18 at 2:17
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
2
2
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
1
1
Don't you rather need a lookup?
items.ToLookup(c => c.CategoryName, c => c.Name)– Antonín Lejsek
Nov 22 '18 at 2:17
Don't you rather need a lookup?
items.ToLookup(c => c.CategoryName, c => c.Name)– Antonín Lejsek
Nov 22 '18 at 2:17
add a comment |
2 Answers
2
active
oldest
votes
2
Here is one more compact solution.
Dictionary<string, List<string>> dictionary = catalogs
.GroupBy(catalog => catalog.CategoryName, catalog => catalog.Name)
.ToDictionary(grouping => grouping.Key, grouping => grouping.ToList());
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
add a comment |
2
You need to use grouping:
var dict = items.GroupBy(c => c.CategoryName).ToDictionary(g => g.Key, g => g.Select(c => c.Name));
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
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
});
}
});
draft saved
draft discarded
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%2f53421175%2fcreate-a-dictionary-of-liststring-from-an-array-of-pocos%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
2
Here is one more compact solution.
Dictionary<string, List<string>> dictionary = catalogs
.GroupBy(catalog => catalog.CategoryName, catalog => catalog.Name)
.ToDictionary(grouping => grouping.Key, grouping => grouping.ToList());
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
add a comment |
2
Here is one more compact solution.
Dictionary<string, List<string>> dictionary = catalogs
.GroupBy(catalog => catalog.CategoryName, catalog => catalog.Name)
.ToDictionary(grouping => grouping.Key, grouping => grouping.ToList());
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
add a comment |
2
2
2
Here is one more compact solution.
Dictionary<string, List<string>> dictionary = catalogs
.GroupBy(catalog => catalog.CategoryName, catalog => catalog.Name)
.ToDictionary(grouping => grouping.Key, grouping => grouping.ToList());
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
Here is one more compact solution.
Dictionary<string, List<string>> dictionary = catalogs
.GroupBy(catalog => catalog.CategoryName, catalog => catalog.Name)
.ToDictionary(grouping => grouping.Key, grouping => grouping.ToList());
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
answered Nov 21 '18 at 22:27
AlesDAlesD
3,049414
3,049414
add a comment |
add a comment |
2
You need to use grouping:
var dict = items.GroupBy(c => c.CategoryName).ToDictionary(g => g.Key, g => g.Select(c => c.Name));
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
add a comment |
2
You need to use grouping:
var dict = items.GroupBy(c => c.CategoryName).ToDictionary(g => g.Key, g => g.Select(c => c.Name));
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
add a comment |
2
2
2
You need to use grouping:
var dict = items.GroupBy(c => c.CategoryName).ToDictionary(g => g.Key, g => g.Select(c => c.Name));
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
You need to use grouping:
var dict = items.GroupBy(c => c.CategoryName).ToDictionary(g => g.Key, g => g.Select(c => c.Name));
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
answered Nov 21 '18 at 22:29
KrzysztofKrzysztof
249216
249216
add a comment |
add a comment |
draft saved
draft discarded
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.
draft saved
draft discarded
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%2f53421175%2fcreate-a-dictionary-of-liststring-from-an-array-of-pocos%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
I want to know if I can imporve my query to not have to reference the catalog list twice. once to iterate and select my keys, then another to initialize the value when I make a dictionary add.
– melmack
Nov 21 '18 at 22:18
Also note you're not iterating it twice, you're iterating it once plus once more for each category.
– Servy
Nov 21 '18 at 22:21
right. added now.
– melmack
Nov 21 '18 at 22:21
2
Use GroupBy followed by ToDictionary.
– Nikola Markovinović
Nov 21 '18 at 22:23
1
Don't you rather need a lookup?
items.ToLookup(c => c.CategoryName, c => c.Name)– Antonín Lejsek
Nov 22 '18 at 2:17