TIMESTAMP

expression-1 and expression-2

The rules for the arguments depend on whether a second argument is specified and the data type of the second argument.

• If only expression-1 is specified:
  The argument must be an expression that returns a value of one of the following built-in data types: a date, a timestamp, a character string, or a graphic string. If expression-1 is a character or graphic string, its value must be one of the following:

  • A valid string representation of a date or a timestamp. For the valid formats of string representations of dates and timestamps, see String representations of datetime values.
  • A character string with an actual length of 13 that is assumed to be a result from a GENERATE_UNIQUE function. For information on GENERATE_UNIQUE, see GENERATE_UNIQUE.
• If both arguments are specified:
  • If the second argument is expression-2:

    The first argument must be an expression that returns a value of one of the following built-in data types: a date, a character string, or a graphic string. If expression-1 is a character or graphic string, its value must be a valid string representation of a date.

    expression-2 must be an expression that returns a value of one of the following built-in data types: a time, a character string, or a graphic string. If expression-2 is a character or graphic string, its value must be a valid string representation of a time. For the valid formats of string representations of dates and times, see String representations of datetime values.

  • If the second argument is precision-constant:
    The first argument must be an expression that returns a value of one of the following built-in data types: a date, a timestamp, a character string, or a graphic string. If expression-1 is a character or graphic string, its value must be one of the following:

    • A valid string representation of a date or timestamp. For the valid formats of string representations of dates and timestamps, see String representations of datetime values.
    • A character string with an actual length of 13 that is assumed to be a result from a GENERATE_UNIQUE function. For information on GENERATE_UNIQUE, see GENERATE_UNIQUE.
    

precision-constant

An integer constant representing the number of fractional seconds. The value must be in the range 0 through 12.

The result of the function is a timestamp. If either argument can be null, the result can be null; if either argument is null, the result is the null value.

The other rules depend on whether the second argument is specified:

• If both arguments are specified and the second argument is expression-2:

  The result is a TIMESTAMP(6) with the date specified by the first argument and the time specified by the second argument. The fractional seconds part of the timestamp is zero.

• If both arguments are specified and the second argument is precision-constant:

  The result is a timestamp with the precision specified by the second argument.

  
• If only one argument is specified and it is a TIMESTAMP(p):

  The result is a TIMESTAMP(p).

• If only one argument is specified and it is a DATE:

  The result is that date with an assumed time of midnight cast to TIMESTAMP(0).

  
• If only one argument is specified and it is a string:

  The result is the TIMESTAMP(6) represented by that string. If the argument is a string of length 14, the timestamp has a fractional seconds part of zero.