Error in converting JSON string to datatable

Question

5.00/5 (1 vote)

See more:

Hi,

I have a requirement to get some data from db using WebAPI and send back to user as a JSON string and convert back it to a datatable. I could not find out what is going wrong. Please suggest.

JSON string
-----------------
"[{\"TestID\":\"1 \",\"WorkOrderID\":\"2 \",\"Recipe\":\"1110 \",\"FitCoeffA\":\"0 \",\"FitCoeffB\":\"0 \",\"FitCoeffC\":\"0 \",\"Temp0\":\"0 \",\"Temp1\":\"0 \",\"Temp2\":\"0 \",\"TestResult\":\"1 \"},{\"TestID\":\"1 \",\"WorkOrderID\":\"2 \",\"Recipe\":\"1110 \",\"FitCoeffA\":\"0 \",\"FitCoeffB\":\"0 \",\"FitCoeffC\":\"0 \",\"Temp0\":\"0 \",\"Temp1\":\"0 \",\"Temp2\":\"0 \",\"TestResult\":\"1 \"}]"

Exception
----------
Unexpected JSON token when reading DataTable. Expected StartArray, got String. Path '', line 1, position 557.

Error stack trace
--------------------

at Newtonsoft.Json.Converters.DataTableConverter.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.DeserializeConvertable(JsonConverter converter, JsonReader reader, Type objectType, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type)
at iMFCTest.Service.iMFCDAL.<getcalibrationdata>d__3.MoveNext() in C:\Users\20063692\source\Workspaces\E-07430-01-01\Solution\iMFCTest\iMFCTest.Service\iMFCDAL.cs:line 61

What I have tried:

I used below code for conversion:
DataTable table=(DataTable)JsonConvert.DeserializeObject(dataString, (typeof(DataTable)));

Posted 18-Apr-18 3:26am

Sumith Peringathara

Updated 24-May-23 23:17pm

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

AkiStar · Answer 1 · 2018-04-18T22:46:00

I have checked and found no issue. Can you please check what JSON you are actually getting and validate it using JSONLint whether json is valid or not? Because the json you mentioned is correct and i was able to convert it into datatable. Check what the json you are exactly getting and validate it.

Check my code:

string s = "[{\"TestID\":\"1 \",\"WorkOrderID\":\"2 \",\"Recipe\":\"1110 \",\"FitCoeffA\":\"0 \",\"FitCoeffB\":\"0 \",\"FitCoeffC\":\"0 \",\"Temp0\":\"0 \",\"Temp1\":\"0 \",\"Temp2\":\"0 \",\"TestResult\":\"1 \"},{\"TestID\":\"1 \",\"WorkOrderID\":\"2 \",\"Recipe\":\"1110 \",\"FitCoeffA\":\"0 \",\"FitCoeffB\":\"0 \",\"FitCoeffC\":\"0 \",\"Temp0\":\"0 \",\"Temp1\":\"0 \",\"Temp2\":\"0 \",\"TestResult\":\"1 \"}]";

DataTable table = (DataTable)JsonConvert.DeserializeObject(s, (typeof(DataTable)));