@cgignite/ignite-odata/helpers/resolvers/s3.js

Odata Connector CG Ignite

const { GetMetadataQuery, GetKeyFromModel, GetWhereClauseString, isEmpty, GetEntity } = require('../functions');

// returns a mysql query based on url, method, req. body and parameters
exports.GetQuery = async (info) => {
  try {
    if (info.method === 'GET') {
      return await this.GetSelectQuery(info);
    }
    else {
      return "S3 doesn't allow data updates using sql";
    }
  } catch (err) {
    return err;
  }
};

exports.GetSelectQuery = async (info) => {
  try {
    query = '';
    full_resource_path = info.resource_path;
    query_params = info.query_params;
    //isolating service root and entity name
    resource_path = full_resource_path.split('/');
    entity = resource_path[2];
    properties = resource_path[3];
    //the resource_path array can have atmost 4 components
    //1 The empty element wrapping the odata root service /ServiceRoot/ or /example/ anything the user might like

    //2 The root or odata element ending in forward slash according to odata convention

    //3 The entity name along with the property for comparison, e.g.
    //e.g.
    //http://127.0.0.1:1880/root/users
    //http://127.0.0.1:1880/root/users('Ravi')

    //4 Property name to fetch raw value of properties passed in the url,
    //Note: Multiple properties must be separeted by comma in url
    //http://127.0.0.1:1880/root/users(UserName='Ravi')/name,class

    //testing if the user requested metdata, batch service request, or data from entity
    if (entity === '$metadata' || entity === '') {
      return query = GetMetadataQuery();
    }
    else if (entity === '$batch') {
      return query = `BatchSegment translation is not supported`;
    }
    else {
      //logic to query data using query parameters in url
      if (isEmpty(query_params) && entity.includes("(")) {
        //case to support get by id in odata e.g. http://127.0.0.1:1880/root/users('Ravi')
        query = 'SELECT * FROM tablename';
        entity_with_param = entity;
        entity_with_param = entity_with_param.substring(0, entity_with_param.length - 1);
        entity_with_param = entity_with_param.split('(');
        entity = entity_with_param[0];
        param = entity_with_param[1];
        query += " WHERE " + GetKeyFromModel(info.data_model, entity) + " = " + param;
        properties ? query = query.replace("*", properties) : query;
        info.schema ? entity = info.schema + '.' + entity : entity;
        return query.replace("tablename", entity);
      } else {
        //case for find by id 
        query = 'SELECT * FROM tablename';
        //to counter user error where user appends user(id) with query parameters
        entity.includes("(") ? entity = GetEntity(entity) : entity;
        //TO add columns name to select staements
        query_params.$select ? query = query.replace("*", query_params.$select) : query;
        if (query_params.$filter) {
          query += " WHERE " + GetWhereClauseString(query_params.$filter);
        }
        orderbyadded = false
        if (query_params.$orderby) {
          query += " ORDER BY " + query_params.$orderby;
          orderbyadded = true;
        }
        if (query_params.$top) {
          if (orderbyadded === true) {
            query += " LIMIT " + query_params.$top;
          }
          else {
            query += " ORDER BY " + GetKeyFromModel(info.data_model, entity) + " LIMIT " + query_params.$top;
            orderbyadded = true;
          }
        }
        if (query_params.$skip) {
          if (orderbyadded === true) {
            query += " OFFSET " + query_params.$skip;
          }
          else {
            query += " ORDER BY " + GetKeyFromModel(info.data_model, entity) + " OFFSET " + query_params.$skip;
            orderbyadded = true;
          }
        }
        // if (!orderbyadded) {
        //   query += " ORDER BY " + GetKeyFromModel(info.data_model, entity);
        // }
        info.schema ? entity = info.schema + '.' + entity : entity;
        return query.replace("tablename", entity);
      }
    }
  } catch (error) {
    return error;
  }
};