ANSI Compliance
This statement is a Teradata extension to the ANSI SQL:2011 standard.
The AT clause is ANSI SQL:2011 compliant.
As an extension to ANSI, the AT clause is supported when using Teradata conversion syntax to convert from TIME to TIMESTAMP. In addition, you can specify the time zone displacement using additional expressions besides an INTERVAL expression.
Syntax
time_expression ( [ data_attribute [,...] ] TIMESTAMP [ ( fractional_seconds_precision ) ] [, WITH TIME ZONE ] [ AT { LOCAL | SOURCE [ TIME ZONE ] | [ TIME ZONE ] { expression | time_zone_string } } ] [, data_attribute [,...] ] )
Syntax Elements
- time_expression
The TIME expression to be converted.
- data_attribute
- One of the following data attributes:
- FORMAT
- NAMED
- TITLE
- fractional_seconds_precision
A single digit representing the number of significant digits in the fractional portion of the SECOND field. The valid range is 0 through 6. The default is 6.
- AT LOCAL
Use the time zone displacement based on the current session time zone.
- AT SOURCE [TIME ZONE]
- Use the time zone associated with timestamp_expression when:
- AT SOURCE TIME ZONE is specified.
- AT SOURCE is specified without TIME ZONE and there is no column named source in the scope.
Otherwise, if AT SOURCE is specified without TIME ZONE and a column named source exists, then SOURCE references this column, and the value of the column is used as the time zone displacement for the CAST. If needed, the column value is implicitly converted to type INTERVAL HOUR(2) TO MINUTE.
- AT [TIME ZONE] expression
Use the time zone displacement defined by expression.
The data type of expression should be INTERVAL HOUR(2) TO MINUTE or it must be a data type that can be implicitly converted to INTERVAL HOUR(2) TO MINUTE.
- AT [TIME ZONE] time_zone_string
- time_zone_string determines the time zone displacement.