I query the database using linq.
I would like to filter the ID_LEAD column by the value of the filter "if there is an int (filter.code) or filter all over the world.
Follow the example of how the procedure is in the bank
WHERE ---- @ID_LEAD ----
LE.ID_LEAD = ISNULL(@ID_LEAD,ID_LEAD)
I would like to do this in my query
var lead = (from l in this.DB.BGC_LEAD
where l.ID_LEAD == ).ToList();
Just check if there is a value in the variable that holds the filter and work on a Boolean expression.
Example
If it is nullable and null it represents the absence of a parameter (that is, return all records):
var lead = (from l in this.DB.BGC_LEAD
where filtro.codigo == null || l.ID_LEAD == filtro.codigo.Value)
.ToList();
If it is a% of normal% and 0 represents the absence of a parameter:
var lead = (from l in this.DB.BGC_LEAD
where filtro.codigo == 0 || l.ID_LEAD == filtro.codigo)
.ToList();
It would be this:
var leadId = 0;
if(parametro == 1)
leadId = 1
else
leadId = 2;
var lead = (from l in this.DB.BGC_LEAD
where l.ID_LEAD ==leadId).ToList();
First, in your SQL query you should do this:
WHERE LE.ID_LEAD = 0 OR ID_LEAD = @ID_LEAD
In LINQ in the same way:
//pId é seu parâmetro (não nulo)
var lead = (from l in this.DB.BGC_LEAD
where l.ID_LEAD == pId || pId == 0).ToList();
If you pass as a parameter the value zero, then it will be true for all occurrences, if you pass something, you will only consider the ID_LEAD equal to the parameter.