---json
{
    "description": "This article shows you how to generate a csv file from a generator tabular file.",
    "low_quality_page": "false",
    "page_id": "dldtsswriy1bmcinb28vy",
    "title": "How to create a CSV File with generated data"
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---
====== Tabulify - How to create a CSV File with generated data ======

===== About =====
This article shows you how to generate a <icon name="carbon:csv" /> [[docs:resource:csv|csv file]] from a [[docs:resource:generator|generator]] [[docs:resource:tabular_file|tabular file]]

<note important>
As a [[docs:resource:generator|generator]] is a [[docs:resource:file|file]], if you use any [[docs:op:op|data operation]] against a [[docs:system:file|file system]] data store, the target created would be a [[docs:resource:file|file]].

Therefore, this is mandatory to use the [[docs:op:fill|fill operation]]
</note>
===== Steps by Step =====

==== Prerequisites ====
  * [[howto:getting_started:1_install|A Tabulify Installation]]
<unit display="none">
<code dos>
tabli data drop --not-strict date_dim.csv@temp
</code>
</unit>

==== Create your generator ====
You first need to create your [[docs:resource:generator|generator data resource]] to define the data that should be generated.

We will take as example the ''d_date--datagen.yml'' generator that generates a ''date dimension''.
<note info>
This generator is explained in this [[d_date|howto]]
</note>

<unit >
<file yaml date_dim--datagen.yml>
Comment: An example of date dimension generator based on the `date_dim` table of TPCDS
Columns:
  - name: d_date_sk
    comment: A surrogate key
    Type: integer
    DataGenerator:
      type: sequence
  - name: d_date
    comment: A business key in date format
    Type: date
    DataGenerator:
      type: sequence
  - name: d_date_id
    comment: A business key in string
    Type: varchar
    DataGenerator:
      type: expression
      ColumnParents: d_date
      expression: "x.toISOString().substring(0,10)"
  - name: d_month_seq
    comment: An ascendant sequence for the month
    Type: integer
    DataGenerator:
      type: expression
      ColumnParents: d_date
      expression: "function pad(number) {if (number < 10) { return '0' + number; } return number; }; x.getFullYear()+''+(pad(x.getMonth()+1))"
  - name: d_day_name
    comment: The name of the day
    Type: varchar
    DataGenerator:
      type: expression
      ColumnParents: d_date
      expression: "var days = ['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday']; days[x.getDay()]"
  - name: d_moy
    comment: the month number in year
    Type: Integer
    DataGenerator:
      type: expression
      ColumnParents: d_date
      expression: "x.getMonth()+1"
  - name: d_year
    comment: The year number
    Type: Varchar
    Precision: 4
    DataGenerator:
      type: expression
      ColumnParents: d_date
      expression: "x.getFullYear()"

</file>
</unit>
==== Run the fill command ====

The below [[docs:tabli:data:fill|data fill]] command will create a [[docs:resource:csv|CSV file]] named ''d_date.csv'' in the [[docs:connection:temp|temporary directory]].
<unit >
<code dos>
tabli data fill --generator-selector date_dim--datagen.yml@howto date_dim.csv@temp
</code>
<console>
Source            Target              Latency (ms)   Row Count   Error   Message   
---------------   -----------------   ------------   ---------   -----   -------   
date_dim@memgen   date_dim.csv@temp   6119           1000
</console>
</unit>

==== Check the result ====

What is the data of the CSV file with the [[docs:tabli:data:head|data head command]]?
<unit >
<code dos>
tabli data head --limit 30 d_date.csv@temp
</code>
<console>

</console>
</unit>