---
url: /process-functions/mapping-create.md
description: >-
  One to one mappings are bidirectional, meaning when used in a cube formula it
  is possible to map from left-to-right and right-to-left.
---

# mapping.create

:::tip
One to one mappings are bidirectional, meaning when used in a cube formula it is possible to map from left-to-right and right-to-left.

One to many mappings will only work in one direction when used in cube formula.
:::

Creates a mapping table with the given name.

```js
mapping.create(mappingName, leftDimensions, rightDimensions, leftMany, rightMany);
```

#### Parameters

* `mappingName` - An identifier used to find the target mapping.
* `leftDimensions` -An Array of strings which are the dimension names to include in the leftside of the mapping.
* `rightDimensions` -An Array of strings which are the dimension names to include in the right side of the mapping.
* `leftMany` - (Optional) A `true` or `false` which determines whether the elements in the left dimensions may map to many right elements.
* `rightMany` -(Optional) A `true` or `false` which determines whether the elements in the right dimensions may map to many left elements.

#### Example

```js
let res = mapping.create("Time to Year and Month", ["Time"], ["Year", "Month"]);
```

`Time to Year and Month`. If the mapping already exists or a dimension does not exist the function will return `false`.

```js
let res = mapping.create("Date to Month", ["Date"], ["Month"], false, true);
```

`Date to Month`. If the mapping already exists or a dimension does not exist the function will return `false`.