> For the complete documentation index, see [llms.txt](https://docs.zingg.ai/0.3.4/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zingg.ai/0.3.4/stepbystep/configuration/field-definitions.md).

# Field Definitions

Defining which fields should appear in the output and whether and how they need to be used in matching

#### fieldDefinition

This is a JSON array representing the fields from the source data to be used for matching, and the kind of matching they need.

Each field denotes a column from the input. Fields have the following JSON attributes:

**fieldName**

The name of the field from the input data schema

**fields**

To be defined later. For now, please keep this as the fieldName

**dataType**

Type of the column - string, integer, double, etc.

**matchType**

The way to match the given field. Multiple match types, separated by commas, can also be used. Here are the different types supported.

#### showConcise

| Match Type             | Description                                                                                                                                                                                                                       | Can be applied to             |
| ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------- |
| FUZZY                  | Broad matches with typos, abbreviations, and other variations.                                                                                                                                                                    | string, integer, double, date |
| EXACT                  | No tolerance with variations, Preferable for country codes, pin codes, and other categorical variables where you expect no variations.                                                                                            | string                        |
| DONT\_USE              | Appears in the output but no computation is done on these. Helpful for fields like ids that are required in the output. DONT\_USE fields are not shown to the user while labeling, if [showConcise](#showconcise) is set to true. | any                           |
| EMAIL                  | Matches only the id part of the email before the @ character                                                                                                                                                                      | any                           |
| PINCODE                | Matches pin codes like xxxxx-xxxx with xxxxx                                                                                                                                                                                      | string                        |
| NULL\_OR\_\_\_BLANK    | By default Zingg marks matches as                                                                                                                                                                                                 | string                        |
| TEXT                   | Compares words overlap between two strings.                                                                                                                                                                                       | string                        |
| NUMERIC                | extracts numbers from strings and compares how many of them are same across both strings                                                                                                                                          |                               |
| NUMERIC\_WITH\_UNITS   | extracts product codes or numbers with units, for example 16gb from strings and compares how many are same across both strings                                                                                                    | string                        |
| ONLY\_ALPHABETS\_EXACT | only looks at the alphabetical characters and compares if they are exactly the same                                                                                                                                               | string                        |
| ONLY\_ALPHABETS\_FUZZY | ignores any numbers in the strings and then does a fuzzy comparison                                                                                                                                                               | string                        |

####