This document introduces the basic syntax and examples of type conversion functions.

Note：

Currently, CLS functions can be used in most regions. If they are required in Beijing, Shanghai, Guangzhou, and Nanjing, please contact smart customer service.

If you need to distinguish more detailed data types when querying and analyzing data, you can use type conversion functions for data type conversion in query and analysis statements.

Note：

Dirty data may exist in logs. You are advised to use the try_cast function to avoid query and analysis failures caused by dirty data.

Function cast

The cast function is used to parse the data type of x. During cast execution, if a value fails to be parsed, the system terminates the entire query and analysis operation.

Syntax

cast(x as type)

Parameters

Return value type

The return value type is determined by the type parameter.

Example

Parse the numeric value 0.01 into a BIGINT value:

* | select cast(0.01 as bigint)

Function try_cast

The try_cast function is used to parse the data type of x. During try_cast execution, if a value fails to be parsed, the system returns NULL and continues processing by skipping the value.

Syntax

try_cast(x as type)

Parameters

Return value type

The return value type is determined by the type parameter.

Example

Parse the remote_user field value into a VARCHAR value:

* | select try_cast(remote_user as varchar)

Appendix: Data Type Mappings

The mappings between index and SQL data types are as follows: