Github user liuyu000 commented on a diff in the pull request:
https://github.com/apache/trafodion/pull/1486#discussion_r176318854
--- Diff:
docs/sql_reference/src/asciidoc/_chapters/sql_functions_and_expressions.adoc ---
@@ -150,67 +150,109 @@ See the individual entry for the function.
== Datetime Functions
These functions use either a datetime value expression as an argument or
-return a result of datetime data type:
+return a result of DATETIME, VALUE or CHAR:
-[cols="25%,75%"]
+[caption="Table 7-3 "]
+.Overview of DATETIME Functions
+[cols="25%,50%,25%"]
|===
+| *Name* | *Description* | *Return Data Type*
| <<add_months_function,ADD_MONTHS Function>>
| Adds the integer number of months specified by _intr_expr_
to _datetime_expr_ and normalizes the result.
+| DATE
| <<converttimestamp_function,CONVERTTIMESTAMP Function>>
| Converts a Julian timestamp to a TIMESTAMP value.
+| TIMESTAMP
| <<current_function,CURRENT Function>> | Returns the current timestamp.
You can also use the
<<current_timestamp_function,CURRENT_TIMESTAMP Function>>.
+| TIMESTAMP
| <<current_date_function,CURRENT_DATE Function>>
| Returns the current date.
+| DATE
| <<current_time_function,CURRENT_TIME Function>>
| Returns the current time.
+| TIME
| <<current_timestamp_function,CURRENT_TIMESTAMP Function>> | Returns the
current timestamp. You can also use the <<current_function,CURRENT Function>>.
+| TIMESTAMP
| <<date_add_function,DATE_ADD Function>>
| Adds the interval specified by _interval_expression_
to _datetime_expr_.
+| DATE
| <<date_part_function_of_an_interval,DATE_PART Function (of an
Interval)>> | Extracts the datetime field specified by _text_ from the interval
value
specified by interval and returns the result as an exact numeric value.
+| NUMERIC VALUE
| <<date_part_function_of_a_timestamp,DATE_PART Function (of a
Timestamp)>> | Extracts the datetime field specified by _text_ from the
datetime value
specified by timestamp and returns the result as an exact numeric value.
+| NUMERIC VALUE
| <<date_sub_function,DATE_SUB Function>>
| Subtracts the specified _interval_expression_ from
_datetime_expr._
+| DATE or TIMESTAMP
| <<date_trunc_function,DATE_TRUNC Function>>
| Returns the date with the time portion of the day truncated.
+| TIMESTAMP
| <<dateadd_function,DATEADD Function>>
| Adds the interval specified by _datepart_ and _num_expr_
to _datetime_expr_.
+| DATE or TIMESTAMP
| <<datediff_function,DATEDIFF Function>>
| Returns the integer value for the number of _datepart_ units of time
between _startdate_ and _enddate_.
+| INTEGER VALUE
--- End diff --
@DaveBirdsall Thanks for your correction, I've changed "INTEGER VALUE" to
"INTERGER".
---
