# Type Conversion

## CAST

`CAST(value AS typename)`

**Description**

Convert the value to the other data type. CAST() may fail if some value cannot be converted to the specified type.

The type name can be STRING, BOOL, FLOAT64, INT64, NUMERIC, DATE, DATETIME, TIME, TIMESTAMP.

**Example**

```
CAST(123 AS STRING)
```

Result: "123"

```
CAST("apple" AS INT64)
```

Result: raising an error

## SAFE\_CAST

`SAFE_CAST(expression AS typename)`

**Description**

Convert the value to the other data type. SAFE\_CAST() is identical to CAST(), but it never fails. It returns NULL when facing an error.

The type name can be STRING, BOOL, FLOAT64, INT64, NUMERIC, DATE, DATETIME, TIME, TIMESTAMP.

**Example**

```
SAFE_CAST(123 AS STRING)
```

Result: "123"

```
SAFE_CAST("apple" AS INT64)
```

Result: null

## DATE

`Date(date_expression)`

**Description**

Convert a string, timestamp, or datetime expression to a date variable in a "yyyy-mm-dd" format. For the timestamp inputs, you can optionally specify a time zone.

**Example**

```
DATE("2016-12-25")
```

Result: 2016-12-25

```
DATE(DATETIME("2016-12-25 23:59:59"))
```

Result: 2016-12-25

```
DATE(TIMESTAMP("2016-12-25 05:30:00+07"), "America/Los_Angeles")
```

Result: 2016-12-24

## DATETIME

`DATETIME(datetime_expression)`

**Description**

Convert a string, timestamp, or date expression to a datetime variable in a "yyyy-mm-dd hh-mm-ss" format. For the timestamp inputs, you can optionally specify a time zone.

**Example**

```
DATETIME("2020-12-01 14:20:32")
```

Result: 2020-12-01T14:20:32

```
DATETIME(TIMESTAMP("2020-12-01 14:20:32+07"), "America/Los_Angeles")
```

Result: 2020-11-30T23:20:32

## TIMESTAMP

`TIMESTAMP(timestamp_expression)`

**Description**

Convert a string, date, or datetime expression to a timestamp variable.

**Example**

```
TIMESTAMP("2020-12-25 15:30:00 UTC")
```

Result: 2020-12-25 15:30:00 UTC

## TIME

`TIME(time_expression)`

**Description**

Convert a string, timestamp, or datetime expression to a time variable in a "hh-mm-ss" format. For the timestamp inputs, you can optionally specify a time zone.

**Example**

```
TIME(TIMESTAMP("2020-12-25 15:30:00+08"), "America/Los_Angeles")
```

Result: 23:30:00