Replace values in multiple rows in multiple columns provided a mapped object for each column

Question

In the following table, I need to replace values in name and class columns using the following objects

+----------------+
| id name  class |
+----------------+
| 1   a     x    |
| 2   b     y    |
| 3   a     z    |
+----------------+

name 
{
    a: "John",
    b: "Jill"
}

class
{
    x: "Maths",
    y: "Science",
    z: "Arts"
}

Final table should look like the following:

+----------------------+
|    id name  class    |
+----------------------+
| 1   John     Maths   |
| 2   Jill     Science |
| 3   John     Arts    |
+----------------------+

What's an efficient way to achieve this in dexie.js?

score 1 · Accepted Answer · answered Oct 04 '17 at 11:37

You will need to scan through the entire table and replace rows one by one.

var map = {
  "name": {
    "a": "John",
    "b": "Jill"
  },
  "class": {
    "x": "Maths",
    "y": "Science",
    "z": "Arts"
  }
};

var db = new Dexie('yourdbname');
db.version(1).stores({
  yourTable: 'id'
});

db.yourTable.toCollection().modify(row => 
  Object.keys(map).forEach(column => row[column] = map[column][row[column]]));

Replace values in multiple rows in multiple columns provided a mapped object for each column

1 Answers1