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Expression And Filter

Amr Moniem answered on March 20, 2022 Popularity 4/10 Helpfulness 1/10

answer Expression And Filter

Expression And Filter

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public async Task<UserData> GetUserByName(string name)

    {

      BinaryExpression filter = null;
      var data = new Dictionary<string, string>();
      data.Add("name", name);
      data.Add("technology", ".Net");
      var userData = Expression.Parameter(typeof(UserData));
      foreach (var toProcess in data)
      {
        var memberExpression = Expression.PropertyOrField(userData, toProcess.Key);
        var constantExpression = Expression.Constant(toProcess.Value);
        var binaryExpression = Expression.Equal(memberExpression, constantExpression); 
        filter = (filter != null) ? Expression.And(filter, binaryExpression) : binaryExpression;

      } 
      Expression<Func<UserData, bool>> lambda = Expression.Lambda<Func<UserData, bool>>(filter, userData);
      return await _dbContext.UserData.Where(lambda).FirstOrDefaultAsync();
    }

Popularity 4/10 Helpfulness 1/10 Language csharp

Source: www.partech.nl

Tags: c# expression filter

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Contributed on Mar 20 2022

Amr Moniem

0 Answers Avg Quality 2/10

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