C# if element not found, then something else
1
I have a simple table
Here's a snippet of my code.
var person = db.Person.Where(p => p.ID == inputId).Select(o => o.ID).FirstOrDefault();
return person;
inputId is a user input field. What I need is if the inputId is not in the table (eg. 5, 6, 7, ect), I want an if/else option to create a new user/reenter a correct id.
Thanks
c# linq
edited Nov 22 '18 at 7:14
Just code
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
add a comment |
1
I have a simple table
Here's a snippet of my code.
var person = db.Person.Where(p => p.ID == inputId).Select(o => o.ID).FirstOrDefault();
return person;
inputId is a user input field. What I need is if the inputId is not in the table (eg. 5, 6, 7, ect), I want an if/else option to create a new user/reenter a correct id.
Thanks
c# linq
edited Nov 22 '18 at 7:14
Just code
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
3
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
1
so you have heard of theif/elseconstruct but do not know how to use it?
– JohnB
Nov 22 '18 at 7:19
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22
add a comment |
1
1
1
I have a simple table
Here's a snippet of my code.
var person = db.Person.Where(p => p.ID == inputId).Select(o => o.ID).FirstOrDefault();
return person;
inputId is a user input field. What I need is if the inputId is not in the table (eg. 5, 6, 7, ect), I want an if/else option to create a new user/reenter a correct id.
Thanks
c# linq
edited Nov 22 '18 at 7:14
Just code
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
I have a simple table
Here's a snippet of my code.
var person = db.Person.Where(p => p.ID == inputId).Select(o => o.ID).FirstOrDefault();
return person;
inputId is a user input field. What I need is if the inputId is not in the table (eg. 5, 6, 7, ect), I want an if/else option to create a new user/reenter a correct id.
Thanks
c# linq
c# linq
edited Nov 22 '18 at 7:14
Just code
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
edited Nov 22 '18 at 7:14
Just code
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
edited Nov 22 '18 at 7:14
Just code
9,90752966
edited Nov 22 '18 at 7:14
Just code
9,90752966
edited Nov 22 '18 at 7:14
Just code
9,90752966
9,90752966
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
asked Nov 22 '18 at 7:13
MBrewersMBrewers
545
545
3
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
1
so you have heard of theif/elseconstruct but do not know how to use it?
– JohnB
Nov 22 '18 at 7:19
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22
add a comment |
3
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
1
so you have heard of theif/elseconstruct but do not know how to use it?
– JohnB
Nov 22 '18 at 7:19
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22
3
3
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
1
1
so you have heard of the
if/else construct but do not know how to use it?– JohnB
Nov 22 '18 at 7:19
so you have heard of the
if/else construct but do not know how to use it?– JohnB
Nov 22 '18 at 7:19
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22
add a comment |
4 Answers
4
active
oldest
votes
5
The null-coalescing operator is one way
var person = db.Person.FirstOrDefault(p => p.ID == inputId) ?? new Person();
edited Nov 22 '18 at 7:32
Jannik
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
add a comment |
2
First of all, you return the ID, not the person. To return a person, you should do this:
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
As for the question, I would prefer this option:
if (db.Person.FirstOrDefault(p => p.ID == inputId) is Person person)
{
//...
}
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
add a comment |
0
first select record
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
if(person == null) //check if not exist
{
//add
db.Person.Add(PersonDetails);
db.SaveChanges();
}
// else return person object
return person;
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
add a comment |
-1
You can check existence of record with .Any() method:
if(db.Person.Any(p => p.ID == inputID))
{
return db.Person.First(p => p.ID == inputID);
}
else
{
//Set user notification message
}
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
5
The null-coalescing operator is one way
var person = db.Person.FirstOrDefault(p => p.ID == inputId) ?? new Person();
edited Nov 22 '18 at 7:32
Jannik
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
add a comment |
5
The null-coalescing operator is one way
var person = db.Person.FirstOrDefault(p => p.ID == inputId) ?? new Person();
edited Nov 22 '18 at 7:32
Jannik
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
add a comment |
5
5
5
The null-coalescing operator is one way
var person = db.Person.FirstOrDefault(p => p.ID == inputId) ?? new Person();
edited Nov 22 '18 at 7:32
Jannik
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
The null-coalescing operator is one way
var person = db.Person.FirstOrDefault(p => p.ID == inputId) ?? new Person();
edited Nov 22 '18 at 7:32
Jannik
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
edited Nov 22 '18 at 7:32
Jannik
1,05621844
edited Nov 22 '18 at 7:32
Jannik
1,05621844
edited Nov 22 '18 at 7:32
Jannik
1,05621844
1,05621844
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
answered Nov 22 '18 at 7:18
fubofubo
29.6k966104
29.6k966104
add a comment |
add a comment |
2
First of all, you return the ID, not the person. To return a person, you should do this:
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
As for the question, I would prefer this option:
if (db.Person.FirstOrDefault(p => p.ID == inputId) is Person person)
{
//...
}
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
add a comment |
2
First of all, you return the ID, not the person. To return a person, you should do this:
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
As for the question, I would prefer this option:
if (db.Person.FirstOrDefault(p => p.ID == inputId) is Person person)
{
//...
}
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
add a comment |
2
2
2
First of all, you return the ID, not the person. To return a person, you should do this:
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
As for the question, I would prefer this option:
if (db.Person.FirstOrDefault(p => p.ID == inputId) is Person person)
{
//...
}
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
First of all, you return the ID, not the person. To return a person, you should do this:
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
As for the question, I would prefer this option:
if (db.Person.FirstOrDefault(p => p.ID == inputId) is Person person)
{
//...
}
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
answered Nov 22 '18 at 7:39
Stanislav MolchanovskyStanislav Molchanovsky
467116
467116
add a comment |
add a comment |
0
first select record
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
if(person == null) //check if not exist
{
//add
db.Person.Add(PersonDetails);
db.SaveChanges();
}
// else return person object
return person;
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
add a comment |
0
first select record
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
if(person == null) //check if not exist
{
//add
db.Person.Add(PersonDetails);
db.SaveChanges();
}
// else return person object
return person;
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
add a comment |
0
0
0
first select record
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
if(person == null) //check if not exist
{
//add
db.Person.Add(PersonDetails);
db.SaveChanges();
}
// else return person object
return person;
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
first select record
var person = db.Person.FirstOrDefault(p => p.ID == inputId);
if(person == null) //check if not exist
{
//add
db.Person.Add(PersonDetails);
db.SaveChanges();
}
// else return person object
return person;
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
edited Nov 22 '18 at 7:28
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
answered Nov 22 '18 at 7:23
SaifSaif
1,0431723
1,0431723
add a comment |
add a comment |
-1
You can check existence of record with .Any() method:
if(db.Person.Any(p => p.ID == inputID))
{
return db.Person.First(p => p.ID == inputID);
}
else
{
//Set user notification message
}
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
add a comment |
-1
You can check existence of record with .Any() method:
if(db.Person.Any(p => p.ID == inputID))
{
return db.Person.First(p => p.ID == inputID);
}
else
{
//Set user notification message
}
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
add a comment |
-1
-1
-1
You can check existence of record with .Any() method:
if(db.Person.Any(p => p.ID == inputID))
{
return db.Person.First(p => p.ID == inputID);
}
else
{
//Set user notification message
}
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
You can check existence of record with .Any() method:
if(db.Person.Any(p => p.ID == inputID))
{
return db.Person.First(p => p.ID == inputID);
}
else
{
//Set user notification message
}
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
answered Nov 22 '18 at 8:23
OleksiiYatsenkoOleksiiYatsenko
30339
30339
add a comment |
add a comment |
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3
So what are you waiting for?
– Just code
Nov 22 '18 at 7:15
Check if any exist then db.Person.Any(p => p.ID == inputId)
– Marcus Höglund
Nov 22 '18 at 7:16
if person is null then that is your else statement
– brykneval
Nov 22 '18 at 7:16
1
so you have heard of the
if/elseconstruct but do not know how to use it?– JohnB
Nov 22 '18 at 7:19
That's a verbose way to just check if an ID exists... also naming a variable person, but putting only an ID in it is a good way to confuse your fellow programmers ;)
– oerkelens
Nov 22 '18 at 7:22