Duplicate Record is inserting in DB in ASP.NET WEB API

Question

While concurrent request is hitting to API it started to save duplicate record rather than checking condtion of duplicate record

 

I am sharing you my code

 

if (!db.dbMySampleDataSummary.Any(w => w.userid == id && w.clientId == tokenId))

{

MySampleDataSummary mySampleData = new MySampleDataSummary();

mySampleData.userid = id;

mySampleData.clientId = tokenId;

mySampleData.remarks = "remarks here for testing";

mySampleData.mobile = "0123456789";

mySampleData.approvedBy = "test user";

mySampleData.approvalStatus = true;

mySampleData.approvalDate = "2019-11-28";

mySampleData.isListed = true;

db.dbMySampleDataSummary.Add(mySampleData);

db.SaveChanges();

}