Fractional Seconds in Time Values ); CREATE TABLE t (ts TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP); CREATE TABLE t1 (ts TIMESTAMP NULL DEFAULT ’0000-00-00 00:00:00’); CREATE TABLE t2 (ts TIMESTAMP NULL DEFAULT NULL); INSERT INTO t2 VALUES (CURRENT_TIMESTAMP); INSERT INTO t1 VALUES (NOW()); CREATE TABLE t1 (t TIME(3), dt DATETIME(6)); CREATE TABLE fractest( c1 TIME(2), c2 DATETIME(2), c3 TIMESTAMP(2) ); INSERT INTO fractest VALUES (’17:51:04.777’, ’2018-09-08 17:51:04.777’, ’2018-09-08 17:51:04.777’); mysql>  SELECT * FROM fractest; +-------------+------------------------+------------------------+ | c1 | c2 | c3 | A  TIMESTAMP  column that permits  NULL  values does  not  take on the current timestamp at insert time except under one of the following conditions: In other words, a  TIMESTAMP  column defined to permit  NULL  values auto-initializes only if its definition includes  DEFAULT CURRENT_TIMESTAMP : If the  TIMESTAMP  column permits  NULL  values but its definition does not include  DEFAULT CURRENT_TIMESTAMP , you must explicitly insert a value corresponding to the current date and time. Suppose that tables  t1  and  t2  have these definitions: To set the  TIMESTAMP  column in either table to the current timestamp at insert time, explicitly assign it that value. For example: If the  explicit_defaults_for_timestamp  system variable is enabled,  TIMESTAMP  columns permit NULL  values only if declared with the  NULL  attribute. Also,  TIMESTAMP  columns do not permit assigning NULL  to assign the current timestamp, whether declared with the  NULL  or  NOT NULL  attribute. To assign the current timestamp, set the column to  CURRENT_TIMESTAMP  or a synonym such as  NOW() . MySQL has fractional seconds support for  TIME ,  DATETIME , and  TIMESTAMP  values, with up to microseconds (6 digits) precision: The  fsp  value, if given, must be in the range 0 to 6. A value of 0 signifies that there is no fractional part. If omitted, the default precision is 0. (This differs from the standard SQL default of 6, for compatibility with previous MySQL versions.) The temporal values are inserted into the table with rounding: •Its default value is defined as  CURRENT_TIMESTAMP  and no value is specified for the column • CURRENT_TIMESTAMP  or any of its synonyms such as  NOW()  is explicitly inserted into the column •To define a column that includes a fractional seconds part, use the syntax  type_name ( fsp ) , where type_name  is  TIME ,  DATETIME , or  TIMESTAMP , and  fsp  is the fractional seconds precision. For example: •Inserting a  TIME ,  DATE , or  TIMESTAMP  value with a fractional seconds part into a column of the same type but having fewer fractional digits results in rounding. Consider a table created and populated as follows: 2032 11.2.6 Fractional Seconds in Time Values