---
title: "Datastore Wildcards"
description: "If you need to transfer data from CSV or Fixed Width files, it is likely that they are being created with a varying filename to identify the date and time of creation. In the CSV and Fixed Width Datastores there is a function to store wildcards so that the filename used in the process is constant but each of the actual files can be processed."
url: "https://eightwire.io/knowledge-base/datastore-wildcards/"
category: "Datastore Features"
generated: "2026-09-16"
---
# Datastore Wildcards

> If you need to transfer data from CSV or Fixed Width files, it is likely that they are being created with a varying filename to identify the date and time of creation. In the CSV and Fixed Width Datastores there is a function to store wildcards so that the filename used in the process is constant but each of the actual files can be processed.

![Files DataFileExample\_20200912\_1.txt to \_20200914\_3.txt → wildcard DataFileExample.txt → process → table dbo.DataLoaded, loaded once by last modified date](https://eightwire.io/_astro/datastore-wildcards-1.C1GvgSzi_Z1ohhp0.webp)

Once a process is run on a file (determined by the LastModifiedDate) it cannot process again, preventing any data loads duplicated to your source.

> *If you need to process a file again, simply edit it so that the LastModifiedDate is changed — then the process will identify the file as new and will transfer the data again.*

## Wildcard Symbols

   **\[ \]** Within the brackets the type of characteristics expected are specified, for example, \[0–9\] means you can see any numbers within that range, \[A–Z\] allows any            alphabetical characters within that range.

   **{ }**  Within the braces, the first number denotes the maximum amount of characters, the second number denotes the maximum number of characters expected.

    **^**   Literal to start or end an expected string.

## Create a Wildcard

1.  Create a CSV Datastore — it must be a source.
2.  Note that in the file path, the files can be seen using their complete filename convention.

![File Explorer listing six files ExistingClientList\_20200301\_A to ExistingClientList\_20200302\_C with Date modified column](https://eightwire.io/_astro/datastore-wildcards-2.Bvnyyq0X_zRUiw.webp)

![Browsing Client Lists panel listing ExistingClientList\_20200301\_A.csv to \_20200302\_C.csv with Test Connection and Scan for Changes buttons](https://eightwire.io/_astro/datastore-wildcards-3.D1vKMuTm_2nrPt5.webp)

3\. In the datastore go to the last tab — Filename Wildcards.

4\. Click **\+ New Wildcard**

5\. Give your filename an alias — this is how the file will appear in the Datastore.

![Filename wildcards tab with alias ClientList.csv, value ^ExistingClientList\_\[0-9\]{8}\_\[A-Z\]{1}.csv, + New Wildcard and Save buttons](./images/datastore-wildcards-4.webp)

6\. In the value field save an expression that allocates variables \[0-9\] for numbers and \[A-Z\] for letters. Any other characters are expressed as they appear.  End the string with the file extension as it appears in windows explorer. Select **Save**.

7\. Click **Scan** > select **Save**

    Your datastore now appears with a constant filename.

![Browsing Client Lists panel now listing the single wildcard file ClientList.csv with Test Connection and Scan for Changes buttons](https://eightwire.io/_astro/datastore-wildcards-5.TU_zN-Iu_2in1CJ.webp)

> *If a process executes and all the files have already transferred the error message will say "your datastore is empty".*

> *If a process is created using a filename and then subsequently a wildcard is applied - your datastore will scan with an error saying that the file no longer exists but is being used in a process. To fix - just recreate a process using the wildcard filename and delete the previous one.*