current_timestamp() not treated as sql literal

[christoph-blessing]

Bug Report

Description

@schema
class Table(dj.Manual):
    definition = """
        t = CURRENT_TIMESTAMP : timestamp
    """

@schema  # pymysql.err.OperationalError: (1067, "Invalid default value for 't'")
class Copy(dj.Manual):
    definition = (Table().heading)  # or 'Table().describe()'

In my case the server returns current_timestamp() as the default value for t but that value is not treated as a sql literal by datajoint. Therefore datajoint surrounds the value with quotation marks making it an invalid default value and leading to the error. One fix is to add current_timestamp() to the list of literals here. I would be happy to make a PR if you agree with that fix.

Reproducibility

• DataJoint Version 0.14.1
• MariaDB Version 10.3.38

[christoph-blessing]

This doesn't happen when using mysql 5.7.33.