How to Delete the Odd Rows Of A Table In Oracle?

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To delete the odd rows of a table in Oracle, you can use a combination of the ROWID pseudo column and the MOD function. You can first select the odd rows by using the following query:


SELECT * FROM table_name WHERE MOD(ROWID, 2) = 1;


This query selects all rows where the ROWID value is odd. After confirming that the query selects the correct rows, you can then use the DELETE statement to remove these rows from the table:


DELETE FROM table_name WHERE MOD(ROWID, 2) = 1;


This will delete all odd rows from the table in Oracle. Remember to always back up your data before performing any delete operation, as it cannot be undone.

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How to delete specific rows based on row number in Oracle?

To delete specific rows based on row number in Oracle, you can use the following SQL query:

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DELETE FROM your_table
WHERE rowid IN (
    SELECT rowid
    FROM your_table
    WHERE rownum IN (row_number1, row_number2, ...)
);


In this query, replace your_table with the name of your table and row_number1, row_number2, ... with the row numbers of the rows you want to delete.


For example, if you want to delete rows with row numbers 3, 5, and 7 in a table called employees, you can use the following query:

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DELETE FROM employees
WHERE rowid IN (
    SELECT rowid
    FROM employees
    WHERE rownum IN (3, 5, 7);
);


Please note that the ROWNUM pseudocolumn is assigned to a row after it passes a WHERE clause so using ROWNUM directly in the WHERE clause of the subquery will not return the desired row number. In such cases, you can use a subquery to fetch the ROWID values for the rows with the desired row numbers and then use those ROWID values in the DELETE statement.


How to remove odd row numbers from an Oracle table?

To remove odd row numbers from an Oracle table, you can use a combination of a subquery and a common table expression (CTE). Here's an example query to achieve this:

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WITH cte AS (
  SELECT rowid, ROW_NUMBER() OVER (ORDER BY rowid) AS rn
  FROM your_table
)

DELETE FROM your_table
WHERE rowid IN (
  SELECT rowid
  FROM cte
  WHERE rn % 2 != 0
);


In this query:

  1. The CTE cte is used to assign row numbers to each row in the table based on the rowid column.
  2. The DELETE statement then deletes rows from the table where the rowid is in the result set of the subquery, which includes only rows with odd row numbers.


Please replace your_table with the name of your actual table in the query. Make sure to backup your data before performing any DELETE operations.


How can I delete rows with even row numbers in Oracle?

You can delete rows with even row numbers in Oracle by using the following SQL statement:

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DELETE FROM your_table
WHERE MOD(rownum, 2) = 0;


This statement will delete all rows with even row numbers from the your_table table. The MOD(rownum, 2) = 0 condition is used to filter out the even row numbers.


What is the best way to delete odd-numbered rows in Oracle?

One way to delete odd-numbered rows in Oracle is to use a combination of the ROWNUM pseudo-column and the MOD function. Here is an example query that deletes odd-numbered rows from a table:

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DELETE FROM your_table
WHERE MOD(ROWNUM, 2) = 1;


In this query, the ROWNUM pseudo-column is used to number each row in the result set. The MOD function is then used to determine if the row number is odd (when divided by 2, the remainder is 1). By specifying MOD(ROWNUM, 2) = 1 in the WHERE clause, only odd-numbered rows will be selected for deletion.


Please note that deleting rows can have serious consequences, so make sure to back up your data before running any delete queries.


How to remove every other row in Oracle table?

One way to remove every other row in an Oracle table is to use a subquery that selects the rows you want to keep and then delete all other rows. Here is an example:

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DELETE FROM your_table
WHERE rowid NOT IN (
  SELECT rowid
  FROM your_table
  WHERE rownum % 2 = 0
);


This query will delete all rows in the your_table except for every other row. The rownum % 2 = 0 condition in the subquery only selects rows with an even row number, effectively removing every other row.


Please make sure to replace your_table with the name of your actual table. Also, it's always a good idea to backup your data before running a delete query to prevent accidental data loss.


How to skip odd rows when deleting in Oracle?

To skip odd rows when deleting in Oracle, you can use a query that uses the MOD function to filter out the odd rows. Here is an example query that deletes only the even rows from a table named example_table:

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DELETE FROM example_table
WHERE MOD(rownum, 2) = 0;


In this query, the MOD(rownum, 2) function calculates the remainder when dividing the row number by 2. If the remainder is 0, it means the row number is even and the row is deleted.


Make sure to replace example_table with the actual name of the table you want to delete from.

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