I have a table with 30 columns, and it contains 1000 rows. I want a single LINQ query, which checks for a particular value in all columns and converts the result into a list.
For example:
table.where(allcolumnvalue.contains(searchvalue)).Tolist()
How to accomplish the above using one LINQ query. Any help is much appreciated.
For your request all of fields should have same type, at least in the static typed C#.
The method Queriable.Where
gets the Expression<Func<T, bool>>
predicate as parameter. So you need build the predicate o.p1 == val || o.p2 == val || o.p3 = val ...
o.p1 == val || o.p2 == val || o.p3 = val ...
o.p1 == val || o.p2 == val || o.p3 = val ...
as Expression
value. Here o
is a parameter of Expression<Func<T, bool>>
:
public Expression BuildExpression<TObj, TVal>(TObj obj, TVal val)
{
Expression<Func<TObj, bool>> predicate = (o) => o.p1 == val || ... || o.pN == val;
return predicate;
}
but we need build predicate dynamically for all properties of TObj
that have type TVal
.
To simplify the code we will build equal expression false || o.p1 == val || ... || o.pN == val
false || o.p1 == val || ... || o.pN == val
false || o.p1 == val || ... || o.pN == val
.
public Expression<Func<TObj, bool>> BuildExpression<TObj, TVal>(TVal val)
{
var parameter = Expression.Parameter(typeof(TObj), "o");
var valExpression = Expression.Constant(val, typeof(TVal));
var body = Expression.Constant(false, typeof(bool));
var properties = typeof(TObj).GetProperties()
.Where(p => p.PropertyType == typeof(TVal));
foreach (var property in properties)
{
var propertyExpression = Expression.Property(parameter, property);
var equalExpression = Expression.Equal(propertyExpression, valExpression);
body = Expression.Or(body, equalExpression);
}
return Expression.Lambda<Func<TObj, bool>>(body, parameter);
}
. . .
using (var dbContext = new DbContext())
{
var whereExpression = BuildExpression<User, string>("foo");
var contaningsFoo = dbContext.Users.Where(whereExpression);
}
I got answer But Is not perfect answer But Is Worked well
public class GenericList<T>
{
void Add(T input) { }
public List<T> SerachFun(List<T> input, string search)
{
List<T> output = new System.Collections.Generic.List<T>();
foreach (var aa in input)
{
var columns = aa.GetType().GetProperties().ToList();
foreach (var bb in columns)
{
var cccc = bb.GetValue(aa);
bool result = cccc.ToString().Contains(search);
if (result)
{
output.Add(aa);
continue;
}
}
}
return output;
}
}
The Generic Class Object Created
public GenericList<table1> g = new GenericList<table1>();
the Generic Class Method Called :
var tabledetails=db.table1.ToList();
var resultcommonsearch = g.SerachFun(tabledetails, "Dhoni");
using code
public class GenericList<T>
{
public List<T> SerachFun(List<T> input, string search)
{
List<T> output = new System.Collections.Generic.List<T>();
foreach (var aa in input)
{
var columns = aa.GetType().GetProperties().ToList();
foreach (var bb in columns)
{
var cccc = bb.GetValue(aa);
if(cccc!=null)
{
bool result = cccc.ToString().Contains(search);
if (result)
{
output.Add(aa);
continue;
}
}
}
}
return output;
}
}
Try call method
public GenericList<table1> g = new GenericList<table1>();
var tabledetails=db.table1.ToList();
var resultcommonsearch = g.SerachFun(tabledetails, "Dhoni");
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