How to pass variable null in entity

Question

How do i pass a variable in the entity where, when this variable is null or empty, the query returns all data to me.

Example:

 public IList<Pessoas> Pessoas { get; set; }

 Pessoas = await _context.Pessoas
                 .Where(s => s.Nome == nome)
                .ToListAsync<Pessoas>();

https://stackoverflow.com/questions/11194/conditional-linq-queries, https://stackoverflow.com/questions/7438382/linq-how-to-exclude-condition-if-parameter-is-null, — CodeCaster, Aug 21 '18 at 12:59

score 1 · Accepted Answer · answered Aug 21 '18 at 13:05

1

You can use double pipes(or ) || operator.

Pessoas = await _context.Pessoas
                 .Where(s => s.Nome == nome || string.IsNullOrEmpty(nome))
                .ToListAsync<Pessoas>();

answered Aug 21 '18 at 13:05

maulik kansara

1,087
6
21

That's exactly what I was looking for. Thank you very much. – Renato Aug 21 '18 at 13:09
Then you should mark the answer as well. – maulik kansara Aug 21 '18 at 13:10
How to do this with int variable ?? – Renato Aug 21 '18 at 13:12
Integer variable will contains Zero as default value so that you can check for zero in or condition – maulik kansara Aug 21 '18 at 13:13
But then, how do I do to return all values without doing an if ?? – Renato Aug 21 '18 at 13:18
lets say nome is of type integer. then its default value will be 0. if nothing assigned to that variable and if you want all records then your condition should be lie "s.Nome == nome || nome==0" – maulik kansara Aug 21 '18 at 13:20
But then in this example, when I put, "name == 0" it returns me values that are null in the database that are saved as default 0, and the ones that really have value it does not. – Renato Aug 21 '18 at 13:25
have you tried? we are not using "s.Nome==0"(column name) we are using "namo==0" variable directly. – maulik kansara Aug 21 '18 at 13:27
solved I put example "name> = 0", then it searches for all values. Thanks a lot for the help. Hugs – Renato Aug 21 '18 at 13:29

score 0 · Answer 2 · answered Aug 21 '18 at 13:08

0

i guess you can try something like

public IList<Pessoas> Pessoas { get; set; }

Pessoas = await _context.Pessoas
                 .Where(s => s.Nome == nome|| string.IsNullOrEmpty(nome))
                .ToListAsync<Pessoas>();

answered Aug 21 '18 at 13:08

ashish shiwalkar

121
10

How to pass variable null in entity

2 Answers2