Postgres UPDATE multiple Row and Value Node.js

postgresql-update-multiple.ts

type UpdateTuple = [primary, value_a, value_b];

async updateMultiple(data: UpdateTuple[]) {
  return this.manager.transaction(async (transactionalManager) => {
    if (data.length === 0) {
      throw 'data cannot be empty';
    }

    // generate parameter index for pgsql query
    const paramsIndex = data.map((v, i) => {
      const index = v.map((_, j) => '$' + (i + i + j + 1));
      return `(${index})`;
    });

    // flatten the data to make odd even order
    const parameters = flatten(data); // using lodash.flatten()

    const queryResult = await transactionalManager.query(
      `UPDATE table_name AS u SET primary = u2.primary, column_a = u2.column_a, column_b = u2.column_b FROM (VALUES ` +
        `${paramsIndex}` +
        `) AS u2(primary, column_a, column_b) WHERE u2.primary = u.primary RETURNING u.primary, u.column_a, u.column_b;`,
      parameters
    );

    // result query: 
    // UPDATE table_name AS u 
    // SET primary = u2.primary, column_a = u2.column_a, column_b = u2.column_b 
    // FROM (VALUES 
    //  ($1,$2,$3),
    //  ($4,$5,$6)
    // ) AS u2(primary, column_a, column_b) 
    // WHERE u2.primary = u.primary 
    // RETURNING u.primary, u.column_a, u.column_b; 
    // -- PARAMETERS: [1,"hello","world",2,"multiple","row update"]

      return { returning: queryResult[0], affectedRow: queryResult[1] };
    });
  }