MaxCompute:SHA2

Syntax

string sha2(string|binary <expr>, bigint <number>)

Parameters

Return value

Returns a value of STRING type containing the hexadecimal representation of the SHA-2 hash, computed using the digest length specified by number.

The function returns NULL in either of the following cases:

• Any input parameter is null.

• The number value is not one of the valid values (0, 224, 256, 384, 512).

Usage notes

• SHA-2 is a one-way cryptographic hash function. You cannot reverse the hash to recover the original input.

• Setting number to 0 is equivalent to 256 and produces a SHA-256 hash.

Examples

Example 1: Compute a SHA-256 hash

SELECT sha2('ABC', 256);

Output:

+---------------------------------------------------------------------+
| _c0                                                                 |
+---------------------------------------------------------------------+
| b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78    |
+---------------------------------------------------------------------+

Example 2: NULL input parameter

If either parameter is null, the function returns NULL.

SELECT sha2('ABC', null);

Output:

+------+
| _c0  |
+------+
| NULL |
+------+

Example 3: Invalid number value

If number is not a valid bit length (0, 224, 256, 384, 512), the function returns NULL.

SELECT sha2('ABC', 100);

Output:

+------+
| _c0  |
+------+
| NULL |
+------+

Related functions

For more hash and encoding functions, see Other functions.