How to Print Last Sunday Of the Year In Oracle?

To print the last Sunday of the year in Oracle, you can use the following query:

SELECT NEXT_DAY(TRUNC(TO_DATE('31-DEC-' || TO_CHAR(SYSDATE, 'YYYY'), 'DD-MON-YYYY') - 7, 'YYYY'), 'SUNDAY') FROM DUAL;

This query first constructs the date for the last day of the current year, then subtracts 7 days to get the last Sunday of the year. The NEXT_DAY function is then used to find the next Sunday from this date.

What is the role of the TO_DATE function in working with date values in Oracle?

The TO_DATE function in Oracle is used to convert a character string representing a date into an actual date value. This function takes the date string as input, along with a format model that specifies the format of the date string. The TO_DATE function then converts the date string into the corresponding date value.

For example, if you have a date string in the format 'YYYY-MM-DD' and you want to convert it into a date value, you can use the TO_DATE function like this:

TO_DATE('2021-09-15', 'YYYY-MM-DD')

This will return the date value '15-SEP-21'.

The TO_DATE function is commonly used in SQL queries to convert date strings into date values so that they can be manipulated and compared with other date values. It ensures that date operations are performed accurately and efficiently by converting date strings into the proper date format recognized by Oracle.

How to find the last Sunday of the year using the ADD_MONTHS function in Oracle?

To find the last Sunday of the year using the ADD_MONTHS function in Oracle, you can follow the steps below:

1. Use the ADD_MONTHS function to add the remaining months in the year to the first day of the year. For example, if you want to find the last Sunday of the current year, you can use the following query:

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SELECT ADD_MONTHS(TRUNC(SYSDATE, 'YEAR'), 12 - TO_NUMBER(TO_CHAR(SYSDATE, 'MM'))) AS last_day_of_year
FROM dual;

1. Use the NEXT_DAY function to find the next Sunday after the calculated date. For example, to find the last Sunday of the current year, you can use the following query:

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SELECT NEXT_DAY(ADD_MONTHS(TRUNC(SYSDATE, 'YEAR'), 12 - TO_NUMBER(TO_CHAR(SYSDATE, 'MM'))), 'SUNDAY') AS last_sunday_of_year
FROM dual;

This query will return the date of the last Sunday of the year.

What is the importance of the DECODE function in Oracle?

The DECODE function in Oracle is important because it allows developers to perform conditional logic in SQL queries. With the DECODE function, users can compare a value with multiple expressions and return a result based on the first expression that matches.

This function is commonly used to translate data values from one form to another, or to group data into logical categories. It can also be used to mimic other programming languages' if-then-else logic within SQL queries.

Overall, the DECODE function is a versatile tool that enhances the functionality and readability of SQL queries in Oracle databases.

How to write a query to determine the last Sunday of the year in Oracle?

To determine the last Sunday of the year in Oracle, you can use the following query:

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SELECT MAX(TO_DATE(TO_CHAR(TRUNC(sysdate, 'YEAR') + LEVEL*7, 'YYYY-MM-DD'), 'YYYY-MM-DD') AS last_sunday
FROM dual
CONNECT BY TO_CHAR(TRUNC(sysdate, 'YEAR') + LEVEL*7, 'YYYY') = TO_CHAR(TRUNC(sysdate, 'YEAR'), 'YYYY')
AND TO_CHAR(TRUNC(sysdate, 'YEAR') + LEVEL*7, 'DY') = 'SUN';

This query uses the CONNECT BY clause to generate dates for each Sunday of the year starting from the beginning of the year (January 1st) and LEVEL is used to keep track of the iterations. The MAX function is then used to select the last Sunday of the year.

What is the role of the CASE statement in Oracle queries?

The CASE statement in Oracle queries provides a way to perform conditional logic within SQL statements. It allows you to selectively execute specific statements based on specified conditions. The syntax of the CASE statement is as follows:

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CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    ...
    ELSE default_result
END

In a SELECT query, the CASE statement can be used to create new columns or modify existing columns based on conditions. It can also be used in the WHERE clause to filter rows based on certain conditions.

Overall, the CASE statement enhances the flexibility and functionality of Oracle queries by enabling conditional logic to be applied within the SQL statements.