Following the solution provided in Demo: GraphQL with Oracle Database and node-oracledb, I created a simple Node JS application with Apollo GraphQL. However, I am stuck at converting the result set obtained from Oracle DB to desired form as expected by the GraphQL schema. If I use JSON.Parse on resultset as shown in the link I mentioned above, it is throwing error -

SyntaxError: Unexpected token O in JSON at position 0 at JSON.parse () at Object.getAssets.. executeQuery.js:39:19

This is my first ever code in Node.js and I am still learning. Hence, Can someone please help me understand why is it not working for me. I am logging the results obtained from DB and it's returning 10 records as expected.

Here is my code:

GraphQL schema definition: schema.js

const { gql } = require("apollo-server");

const typeDefs = gql`
    type Asset {
        id: ID!
        account_id: String
        group_id: String            
    }
    
    type Query {
        assets: [Asset]
    }
    `;

module.exports = typeDefs;

Resolver : resolvers.js

const queryrunner = require("./executeQuery.js")

const resolvers = {
    Query: {
        assets: async() => queryrunner.getAssets(),
    },
};

module.exports = resolvers;

Fetching connection from file oracledatasource.js

let connection;
var oracledb = require('oracledb');

module.exports = {
  getConnection : function () {
      
    connection = oracledb.getConnection({
    user          : "username",
    password      : "password",
    connectString : "(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = hostname)(PORT = 1521))(CONNECT_DATA =(SERVICE_NAME = servicename)))"
  });
  console.log("Successfully connected to Oracle!")
  return connection;
  }
}

And executing query in executeQuery.js :

    const conn = require('./oracledatasource')

    module.exports = {

    getAssets : async() => {
      let connection = await conn.getConnection();
      let query = "SELECT\r\n"
              "    CA.ASSET_ID as id,\r\n"
              "    CA.ACCNT_ID as account_id,\r\n"
              "    CA.GROUP_ID as group_id\r\n"         
              "FROM\r\n"
              "    SCHEMA.TABLE CA\r\n"
              "WHERE\r\n"
              "        CA.ACTIVE_FLG = 1\r\n"
              "    AND ROWNUM <= 10";

      console.log(query);
      let result = await connection.execute(query, []);
      connection.release(); 
      
      console.log(result.rows);
      
      return JSON.parse(result.rows);
    }      
  }

index.js is my main file:

const { ApolloServer } = require("apollo-server");
    
const typeDefs = require('./schema');
    
const resolvers = require('./resolvers');
    
const server = new ApolloServer({
    typeDefs,
    resolvers
    //mocks: true
});
    
server.listen().then(({url}) =>
    console.log(`Server running at ${url}`)
);

CodePudding user response：

The solution given for this question - Question helped to get the desired response.

I followed this manual as suggested - node-oracledb and passed outformat to execute() function, which returned the response as an array of objects. This eliminated the need of using JSON.parse.

  const conn = require('./oracledatasource')
  var oracledb = require('oracledb');

  module.exports = {

    getAssets : async() => {
      let connection = await conn.getConnection();
      let query = "SELECT\r\n"
              "    CA.ASSET_ID \"id\",\r\n"
              "    CA.ACCNT_ID \"account_id\",\r\n"
              "    CA.GROUP_ID \"group_id\"\r\n"
              "FROM\r\n"
              "    SCHEMA.TABLE CA\r\n"
              "WHERE\r\n"
              "        CA.ACTIVE_FLG = 1\r\n"
              "    AND ROWNUM <= 10";

      console.log(query);
      let result = await connection.execute(query, [], { outFormat: oracledb.OUT_FORMAT_OBJECT });
      connection.release(); 
      
      console.log(result.rows);
      
      return Object.values(result.rows);      
    }      
  }