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(); }

Amit Gupta · Answer

@sam, when your app is being used by multiple users then its damm hard to restrict duplicates. You can also use storeprocedure at database level, so it can handle duplicates.otherwise its wastage of time.

Sam · Answer

Hi Sagar Malde, No, tokenId is same. While from postman if I requesting same then its not allowing to submit duplicate, But when the same api calling from android app and app requesting multiple time means 50+ request in a second in that case my api is not able to handle it and insert duplicate records.

Sagar Malde · Answer

Hi Sam, What's the tokenid in your concurrent request? Is that different for every request? If yes, than the condition you added for checking duplicacy will never work. Instead remove tokenid condition and just use userid. So your if condition will be if (!db.dbMySampleDataSummary.Any(w => w.userid == id)) That should work

Ashutosh Gupta · Answer

one solution at c# level could be adding threading concept "sync" or monitor etc but i would also prefer to adopt your schema if you allowed. private static object SampleData = new object(); // define at class level. sync(SampleData) { 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(); } } check it out.

Sam · Answer

I am asking for solution guys and you are trying to change primary key in table, There is combination of 4 column for uniqueness, I know very well if I will create a unique by using all four column in that case record will be never duplicate, But my dear brother I want solution from WEB API(C#) codding not from database level.

Amit Gupta · Answer

Duplicacy happens because Data_ID is set to an identity column, it always increment its value upon new row, got the point? You either have to choose another column as primarykey or change your condition accordingly.

Sam · Answer

condition should be " If(test.Count == 0)" but not working still inserting duplicate record, Before giving answer just read async method in web api so you can help me better

Dhara Patel · Answer

Try this code:var test=db.dbMySampleDataSummary.Where(w => w.userid == id && w.clientId == tokenId).ToList(); If(test.Count<0) { 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(); }

Sam · Answer

Yes, Let me explain it There is total 8 columns in table and one Pirmary key column is "Data_ID INT NOT NULL PRIMARY KEY IDENTITY(1,1) " Duplicate record inserting with unique Data_ID Following is example of my table where highlighted color is duplicate data Data_ID UserID CleintID Remarks Mobile 1 1001 C1001 Hello 1234567890 2 1001 C1001 Hello 1234567890 3 1002 C2002 Test Remarks 1020304050 4 1002 C2002 Test Remarks 1020304050

Dhara Patel · Answer

Hi, Are you sure id and tokenId both match with data of table? If one of parameter not match then insert operation will perform.

Amit Gupta · Answer

Have you tried using primarykey in db?