DB2 SQL: Dates and Times p.1/2

The Basics

To get the current date, time, and timestamp using SQL, reference the appropriate DB2 registers:

SELECT current date FROM sysibm.sysdummy1

SELECT current time FROM sysibm.sysdummy1

SELECT current timestamp FROM sysibm.sysdummy1

The sysibm.sysdummy1 table is a special in-memory table that can be used to discover the value of DB2 registers as illustrated above. You can also use the VALUES keyword to evaluate the register or expression. For example, from the DB2 Command Line Processor (CLP), the following SQL statements reveal similar information:

VALUES current date

VALUES current time

VALUES current timestamp

To get the current time or current timestamp adjusted to GMT/CUT, subtract the current timezone register from the current time or timestamp:

current time – current timezone

current timestamp – current timezone

Given a date, time, or timestamp, you can extract the year, month, day, hour, minutes, seconds, and microseconds po rtions independently using the appropriate function:

YEAR (current timestamp)

MONTH (current timestamp)

DAY (current timestamp)

HOUR (current timestamp)

MINUTE (current timestamp)

SECOND (current timestamp)

MICROSECOND (current timestamp)

Extracting the date and time independently from a timestamp:

DATE (current timestamp)

TIME (current timestamp)

You can also perform date and time calculations using plain English:

current date + 1 YEAR

current date + 3 YEARS + 2 MONTHS + 15 DAYS

current time + 5 HOURS – 3 MINUTES + 10 SECONDS

To calculate how many days there are between two dates, you can subtract dates as in the following:

days (current date) – days (date(‘1999-10-22’))

Here is an example of how to get the current timestamp with the microseconds portion reset to zero:

CURRENT TIMESTAMP – MICROSECOND (current timestamp) MICROSECONDS

If you want to concatenate date or time values with other text, you need to convert the value into a character string first. To do this, you can simply use the CHAR() function:

char(current date)

char(current time)

char(current date + 12 hours)

To convert a character string to a date or time value, you can use:

TIMESTAMP (‘2002-10-20-12.00.00.000000’)

TIMESTAMP (‘2002-10-20 12:00:00’)

DATE (‘2002-10-20’)

DATE (’10/20/2002′)

TIME (’12:00:00′)

TIME (‘12.00.00’)


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