In VB .net I'm wanting to run an sqlite select statement to fetch only numeric values from a text field (a4) which contains both numbers and letters.

My sqlite text a4 field data contains data like this:

```
  28 days
  1966
  the 100 years war

```

In would like to be able to fetch

```
  28
  1966
  100

```

The sqlite a4 field has a text data type

This is what I have tried

```
SELECT a4 from data where CAST(a4 AS INTEGER) GLOB '[0-9]'
SELECT a4 FROM data WHERE a4 REGEXP '[0-9]'

```

I have search for an answer but only found MS SQL answer that uses ISNUMERIC which doesn't exist in SQLITE.

Thanks