GoogleSQL for BigQuery supports the following utility functions.
Function list
| Name | Summary |
|---|---|
GENERATE_UUID
|
Produces a random universally unique identifier (UUID) as a
STRING value.
|
TYPEOF
|
Gets the name of the data type for an expression. |
GENERATE_UUID
GENERATE_UUID()
Description
Returns a random universally unique identifier (UUID) as a STRING.
The returned STRING consists of 32 hexadecimal
digits in five groups separated by hyphens in the form 8-4-4-4-12. The
hexadecimal digits represent 122 random bits and 6 fixed bits, in compliance
with RFC 4122 section 4.4.
The returned STRING is lowercase.
Return Data Type
STRING
Example
The following query generates a random UUID.
SELECT GENERATE_UUID() AS uuid;
/*--------------------------------------*
| uuid |
+--------------------------------------+
| 4192bff0-e1e0-43ce-a4db-912808c32493 |
*--------------------------------------*/
TYPEOF
TYPEOF(expression)
Description
Takes an expression and gets the name of the data type for that expression.
Return type
STRING
Examples
The following example produces the name of the data type for the expression
passed into the TYPEOF function. When NULL is passed in, the
supertype, INT64, is produced.
SELECT
TYPEOF(NULL) AS A,
TYPEOF('hello') AS B,
TYPEOF(12+1) AS C,
TYPEOF(4.7) AS D
/*-------+--------+-------+--------*
| A | B | C | D |
+-------+--------+-------+--------+
| INT64 | STRING | INT64 | FLOAT64 |
*-------+--------+-------+--------*/
The following example produces the name of the data type for field y in a
struct.
SELECT
TYPEOF(STRUCT<x INT64, y STRING>(25, 'apples')) AS struct_type,
TYPEOF(STRUCT<x INT64, y STRING>(25, 'apples').y) AS field_type;
/*---------------------------+------------*
| struct_type | field_type |
+---------------------------+------------+
| STRUCT<x INT64, y STRING> | STRING |
*---------------------------+------------*/
The following example produces the name of the data type for elements in an array.
SELECT
TYPEOF(ARRAY<INT64>[25, 32]) AS array_type,
TYPEOF(ARRAY<INT64>[25, 32][0]) AS element_type;
/*--------------+--------------*
| array_type | element_type |
+--------------+--------------+
| ARRAY<INT64> | INT64 |
*--------------+--------------*/