> For the complete documentation index, see [llms.txt](https://ploegert.gitbook.io/til/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ploegert.gitbook.io/til/programmy/linux/is-app-installed/types-and-operators/checking-the-type-of-a-value.md).

# Checking The Type Of A Value

The `pg_typeof()` function allows you to determine the data type of anything in Postgres.

```sql
> select pg_typeof(1);
 pg_typeof
-----------
 integer
(1 row)

> select pg_typeof(true);
 pg_typeof
-----------
 boolean
(1 row)
```

If you try it on an arbitrary string, it is unable to disambiguate which string type (e.g. `text` vs `varchar`).

```sql
> select pg_typeof('hello');
 pg_typeof
-----------
 unknown
(1 row)
```

You just have to be a bit more specific.

```sql
> select pg_typeof('hello'::varchar);
     pg_typeof
-------------------
 character varying
(1 row)
```

[source](http://www.postgresql.org/docs/9.3/static/functions-info.html#FUNCTIONS-INFO-CATALOG-TABLE)