TO_DATE
Converts a character string to a Date/Time datatype. You use the TO_DATE format strings to specify the format of the source strings.
The output port must be Date/Time for TO_DATE expressions.
If you are converting two-digit years with TO_DATE, use either the RR or YY format string. Do not use the YYYY format string.
Syntax
TO_DATE( string [, format] )
The following table describes the arguments for this command:
Argument | Required/ Optional | Description |
|---|
string | Required | Must be a string datatype. Passes the values that you want to convert to dates. You can enter any valid transformation expression. |
format | Optional | Enter a valid TO_DATE format string. The format string must match the parts of the string argument. For example, if you pass the string 'Mar 15 1998 12:43:10AM', you must use the format string 'MON DD YYYY HH12:MI:SSAM'. If you omit the format string, the string value must be in the date format specified in the session. |
Return Value
Date.
TO_DATE always returns a date and time. If you pass a string that does not have a time value, the date returned always includes the time 00:00:00.000000000. You can map the results of this function to any target column with a datetime datatype. If the target column precision is less than nanoseconds, the Data Integration Service truncates the datetime value to match the precision of the target column when it writes datetime values to the target.
NULL if you pass a null value to this function.
Examples
The following expression returns date values for the strings in the DATE_PROMISED port. TO_DATE always returns a date and time. If you pass a string that does not have a time value, the date returned always includes the time 00:00:00.000000000. If you run a session in the twentieth century, the century will be 19. In this example, the current year on the node running the Data Integration Service is 1998. The datetime format for the target column is MON DD YY HH24:MI SS, so the Data Integration Service truncates the datetime value to seconds when it writes to the target:
TO_DATE( DATE_PROMISED, 'MM/DD/YY' )
DATE_PROMISED | RETURN VALUE |
|---|
'01/22/98' | Jan 22 1998 00:00:00 |
'05/03/98' | May 3 1998 00:00:00 |
'11/10/98' | Nov 10 1998 00:00:00 |
'10/19/98' | Oct 19 1998 00:00:00 |
NULL | NULL |
The following expression returns date and time values for the strings in the DATE_PROMISED port. If you pass a string that does not have a time value, the Data Integration Service returns an error. If you run a session in the twentieth century, the century will be 19. The current year on the node running the Data Integration Service is 1998:
TO_DATE( DATE_PROMISED, 'MON DD YYYY HH12:MI:SSAM' )
DATE_PROMISED | RETURN VALUE |
|---|
'Jan 22 1998 02:14:56PM' | Jan 22 1998 02:14:56PM |
'Mar 15 1998 11:11:11AM' | Mar 15 1998 11:11:11AM |
'Jun 18 1998 10:10:10PM' | Jun 18 1998 10:10:10PM |
'October 19 1998' | Error. Integration Service skips this row. |
NULL | NULL |
The following expression converts strings in the SHIP_DATE_MJD_STRING port to date values:
TO_DATE (SHIP_DATE_MJD_STR, 'J')
SHIP_DATE_MJD_STR | RETURN_VALUE |
|---|
'2451544' | Dec 31 1999 00:00:00.000000000 |
'2415021' | Jan 1 1900 00:00:00.000000000 |
Because the J format string does not include the time portion of a date, the return values have the time set to 00:00:00.000000000.
The following expression converts a string to a four-digit year format. The current year is 1998:
TO_DATE( DATE_STR, 'MM/DD/RR')
DATE_STR | RETURN VALUE |
|---|
'04/01/98' | 04/01/1998 00:00:00.000000000 |
'08/17/05' | 08/17/2005 00:00:00.000000000 |
The following expression converts a string to a four-digit year format. The current year is 1998:
TO_DATE( DATE_STR, 'MM/DD/YY')
DATE_STR | RETURN VALUE |
|---|
'04/01/98' | 04/01/1998 00:00:00.000000000 |
'08/17/05' | 08/17/1905 00:00:00.000000000 |
The following expression converts a string to a four-digit year format. The current year is 1998:
TO_DATE( DATE_STR, 'MM/DD/Y')
DATE_STR | RETURN VALUE |
|---|
'04/01/8' | 04/01/1998 00:00:00.000000000 |
'08/17/5' | 08/17/1995 00:00:00.000000000 |
The following expression converts a string to a four-digit year format. The current year is 1998:
TO_DATE( DATE_STR, 'MM/DD/YYY')
DATE_STR | RETURN VALUE |
|---|
'04/01/998' | 04/01/1998 00:00:00.000000000 |
'08/17/995' | 08/17/1995 00:00:00.000000000 |
The following expression converts strings that includes the seconds since midnight to date values:
TO_DATE( DATE_STR, 'MM/DD/YYYY SSSSS')
DATE_STR | RETURN_VALUE |
|---|
'12/31/1999 3783' | 12/31/1999 01:02:03 |
'09/15/1996 86399' | 09/15/1996 23:59:59 |
If the target accepts different date formats, use TO_DATE and IS_DATE with the DECODE function to test for acceptable formats. For example:
DECODE( TRUE,
--test first format
IS_DATE( CLOSE_DATE,'MM/DD/YYYY HH24:MI:SS' ),
--if true, convert to date
TO_DATE( CLOSE_DATE,'MM/DD/YYYY HH24:MI:SS' ),
--test second format; if true, convert to date
IS_DATE( CLOSE_DATE,'MM/DD/YYYY'), TO_DATE( CLOSE_DATE,'MM/DD/YYYY' ),
--test third format; if true, convert to date
IS_DATE( CLOSE_DATE,'MON DD YYYY'), TO_DATE( CLOSE_DATE,'MON DD YYYY'),
--if none of the above
ERROR( 'NOT A VALID DATE') )
You can combine TO_CHAR and TO_DATE to convert a numeric value for a month into the text value for a month using a function such as:
TO_CHAR( TO_DATE( numeric_month, 'MM' ), 'MONTH' )