> ## Documentation Index
> Fetch the complete documentation index at: https://docs.regatta.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# CAST

## Synopsis

```sql theme={null}
CAST ( expression AS target_type );
```

Or the operator:

```sql theme={null}
expression :: target_type ;
```

## Description

The `CAST` function or operator are used to explicitly convert a value from one data type into a another data type.

#### Casting Notes

1. Casting `BOOLEAN`:
   * Casting strings: Only valid strings - ‘true’, ’false’, ’t’, ’f’  (case insensitive) - can be casted.
   * Casting numbers: Only `integral_types` can be converted. Note that all integers except 0 are converted to ‘true’. Zero is converted to ‘false’.
2. When casting different string length without specifying the needed length, the result value is `VARCHAR(max)`.

## Parameters

**`expression`**

The expression can be a constant or a column or any expression that resolves to a single value.

**`target_type`**

The target\_type is the data type to which you want to convert the above expression to, as long as it is
qualified as a valid convert.

## Examples

Convert literal representing a `DATE` into `TIMESTAMP`:

```sql theme={null}
SELECT CAST('2022-12-12' AS TIMESTAMP);
```

Returns: `2022-12-12 00:00:00`. Note that the time was added.

Convert literal representing an `INT` into `STRING`:

```sql theme={null}
SELECT 234567::STRING;
```

Returns: '234567'

Convert literal representing `numeric_type` into `DECIMAL`:

```sql theme={null}
SELECT CAST(10.4572 AS DECIMAL);
```

Returns: 10.4572

Convert the column value `o_date` into `TIMESTAMP`:

```sql theme={null}
SELECT CAST(o_date AS TIMESTAMP) FROM orders;
```