db2日期格式concat特定时间

Question

I'm trying to query data that happened between Yesterday 6 AM and Today 6 AM.

I'm having a problem in concatenation.

This is what I've tried.

Where update_time between date(CURRENT DATE,'mm/dd/yyyy 06:00:00')- 1 DAYS 
                      and date(CURRENT DATE,'mm/dd/yyyy 06:00:00')

Answer 1

Try this:

WHERE UPDATE_TIME 
BETWEEN TIMESTAMP(CHAR(CURRENT DATE,ISO) || ' 06:00:00') - 1 DAY
AND TIMESTAMP(CHAR(CURRENT DATE,ISO) || ' 06:00:00')

Updated to answer X-Zero's comment:

The DB2 function CHAR(CURRENT DATE,ISO) takes the current date, and converts it to a character string in the ISO format. Taking today's date, the CHAR function would return "2012-09-18".

Next, we concatenate (||) a time string to the date string. The space in the time string creates a character DB2 timestamp in the correct format. "2012-09-18 06:00:00".

Finally, the DB2 function TIMESTAMP takes the character DB2 timestamp and converts it to an actual DB2 timestamp.