SQL DAY scalar function in DB2 for i SQL

SQL DAY scalar function in DB2 for i SQL

DAY

The DAY function returns the day part of a value.

Syntax

DAY(expression)

The argument should be an expression that returns either date, timestamp, character string, graphic string, or any numeric data type. The return value is the large integer. Also, the result can be NULL if the argument value is null.

Example#1:

If the argument is a string, the result is the day part that is represented by the string.

SELECT  DAY('2024-03-16') FROM sysibm.sysdummy1

          DAY
           16

Or

SELECT DAY('2024-03-16-15.10.40.456465') FROM sysibm.sysdummy1

          DAY
           16

Example#2:

The result can be null if the argument is null.

Create a table having date field and that allows null value to be inserted.

CREATE TABLE QTEMP/DT (DATE1 DATE )

INSERT INTO QTEMP/DT VALUES(null)

Output

DATE1
-    

select day(date1) from qtemp/dt

DAY ( DATE1 )  
             - 

Returns NULL value as date1 field has NULL value in table qtemp/dt.

Example#3:

If the argument is a timestamp, the result is the day part of the timestamp.

SELECT  DAY(current timestamp) FROM sysibm.sysdummy1

Or

SELECT  DAY(current_timestamp) FROM sysibm.sysdummy1

          DAY
           16

Example#4:

Argument value is the character string '2024076', which represents a date in the format yyyynnn, where yyyy is the year, and nnn is the day of the year.

SELECT   DAY('2024076') FROM sysibm.sysdummy1

DAY ( '2024076' )
             16