tg-knex-query-resolver/query-parser/parse-subquery.js

TeselaGen's Knex based query resolver

var parseExpression = require("./parse-expression");
var countAllowedExpression = [
  "greaterThan",
  "lessThan",
  "greaterThanEquals",
  "lessThanEquals",
  "equals",
];

module.exports = function (filter, joinOperator, parseFilter, entity) {
  var modifier = "";
  if (filter.modifier === "not") modifier = "Not";

  var op = "where" + modifier + "Exists";
  //   var op = "where" + modifier + "In";

  var chainOperator = filter.chainedWith || joinOperator || undefined;
  if (chainOperator === "and") chainOperator = undefined;
  if (chainOperator) op = chainOperator + "Where" + modifier + "Exists";
  //   if (chainOperator) op = chainOperator + "Where" + modifier + "In";
  //   var existsFilter = [{ [filter.key]: filter.foreignKey }];
  var existsFilter = [
    `??.?? = ??.??`,
    [entity, filter.foreignKey, filter.entity, filter.key],
  ];

  //   console.log(`subqry filter: `, filter);

  var subqueryOp = {
    col: filter.foreignKey,
    op: op,
    subqry: [
      { op: "select", args: [filter.key] },
      { op: "from", args: [filter.entity] },
    ],
  };

  filter.filters.forEach((item, idx) => {
    if (idx === 2) {
      subqueryOp.subqry.push(parseFilter(item, undefined, filter.entity));
    } else {
      subqueryOp.subqry.push(parseFilter(item, filter.operator, filter.entity));
    }
  });

  if (filter.countExpression) {
    if (countAllowedExpression.indexOf(countParsedExpression.name) == -1) {
      throw new Error(
        "count expression " + countParsedExpression.name + " not allowed"
      );
    }

    var countParsedExpression = parseExpression(filter.countExpression);
    countParsedExpression.op = "havingRaw";

    var countExpressionOperator = countParsedExpression.args[1];
    var countExpressionOperand = countParsedExpression.args[2];

    countParsedExpression.args = [
      "count(*) " + countExpressionOperator + " ?",
      [countExpressionOperand],
    ];

    subqueryOp.subqry.push({ op: "groupBy", args: [filter.key] });
    subqueryOp.subqry.push(countParsedExpression);
  }

  if (subqueryOp.subqry.length > 2) {
    //additional filters have been applied
    subqueryOp.subqry.push({ op: "andWhereRaw", args: existsFilter });
  } else {
    // no filters have been applied
    subqueryOp.subqry.push({ op: "whereRaw", args: existsFilter });
  }

  return subqueryOp;
};