Entity framework core invalidoperation exception

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I got an exception "

An exception was thrown while attempting to evaluate a LINQ query parameter expression. To show additional information call EnableSensitiveDataLogging() when overriding DbContext.OnConfiguring.

My code:

C#

var temp = db.MyTable.Where(x => x.id == y.Value && z.Name == "Score")
                      .FirstOrDefault();
 if(temp ! = null)
     myDto.Score = temp.Value

What I have tried:

I already checked the temp null.

Posted 7-Sep-19 5:44am

Member 12658724

Updated 15-Apr-20 21:35pm

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phil.o 7-Sep-19 12:36pm

Chances are, the z variable is not related to anything.

2 solutions

Solution 2

I too got the same exception, but not every time. Even I will check for the null value of that object the same as this, Can anyone suggest the best result. Check the query, how I implemented it in my code.

var temp = db.MyTable.Where(x => x.id == y.Value && x.Name == "Score")
.FirstOrDefault();
if(temp ! = null)
myDto.Score = temp.Value

Posted 15-Apr-20 21:36pm

Member 13524915

Comments

CHill60 16-Apr-20 4:18am

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Dave Kreskowiak · Accepted Answer · 2019-09-07T10:38:00

With EF, keep in mind that ANYTHING you put in the Where clause will be converted to the SQL language of the backing database engine.

Anything on the left side of a comparison refers to a column in your database table. You can pass values in on the right side of the comparison, so long as it's convertible to SQL code.

In your case, the EF has no idea what "z" refers to your database table.