I have created a created_time field with BIGINT in a MySQL 5.7 table, now I want to auto generate a Unix millisecond timestamp when I insert a record. Is it possible to do this? I have tried the code below but it failed:

ALTER TABLE db.video_info MODIFY COLUMN created_time bigint(20) 
  • 3
    tip for questions, replace 'tried this but failed' and replace with 'tried this... which generated the error message....'
    – danblack
    Mar 30, 2021 at 4:50

1 Answer 1


MySQL 8.0 supports the expression default like you show.

MySQL 5.7 does not support expressions as default. Only NULL, or a constant value, or CURRENT_TIMESTAMP if it's a DATETIME or TIMESTAMP column.

For MySQL 5.7, you have two alternatives:

  • Declare the column as created_time datetime(3) default current_timestamp(3).

  • Use BIGINT as you are doing, but write a trigger to set the value.


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