code: private String getExtractQuery(String schema, String entity, String inputQuery) {
      String inputColProjection = this.getInputColumnProjection();
      String outputColProjection = this.getOutputColumnProjection();
      String query = inputQuery;
      if (query == null) {
        // if input query is null, build the query from metadata
        query = "SELECT " + outputColProjection + " FROM " + schema + "." + entity;
      } else {
        // replace input column projection with output column projection
        if (StringUtils.isNotBlank(inputColProjection)) {
          query = query.replace(inputColProjection, outputColProjection);
        }
      }
  
      query = addOptionalWatermarkPredicate(query);
      return query;
    }
docs: Build/Format input query in the required format
  
  @param schema
  @param entity
  @param inputQuery
  @return formatted extract query