How To Delete Duplicates In Oracle

Delete Duplicate Records In Sql
How To Delete Duplicates In Oracle Sql
Oracle Delete Select
How To Delete Duplicates In Oracle
Oracle Delete Sql
How To Delete Duplicates In Oracle

In this case, you can use the rowid which is a physical locator that specifies where on storage Oracle stores the row. Because the rowid is unique to each row, you can use it to remove the duplicates as shown below: DELETE FROM fruits WHERE rowid NOT IN (SELECT MIN (rowid) FROM fruits GROUP BY fruitid, fruitname, color). You can use regular expressions and regexpreplace to remove the duplicates after concatenation with listagg: SELECT Num1, RTRIM(REGEXPREPLACE ((listagg(Num2,'-') WITHIN GROUP (ORDER BY Num2) OVER ), ' (^-.) (-1)+ ($ -)', '13'), '-') Num2s FROM ListAggTest. Oracle database concepts, oracle tables, oracle date time functions, oracle views, oracle packages,oracle procedures,oracle functions, oracle pl/sql anonymous blocks, oracle dml operations, oracle ddl operations,oracle triggers,oracle objects,oracle user privileges, oracle table constraints, oracle materialized views, oracle queries, oracle sub queries, oracle correlated queries, oracle joins. War thunder - japanese pacific campaign.

Removing duplicate rows from Oracle tables with SQL can be very tricky, and there are several techniques for identifying and removing duplicate rows from tables:

Subquery to identify duplicate rows
Use RANK to find and remove duplicate table rows
Use self-join to remove duplicate rows
Use analytics to detect and remove duplicate rows
Delete duplicate table rows that contain NULL values

Use subquery to delete duplicate rows

Here we see an example of using SQL to delete duplicate table rows using an SQL subquery to identify duplicate rows, manually specifying the join columns:

DELETE FROM
table_name A
WHERE
a.rowid >
ANY (
SELECT
B.rowid
FROM
table_name B
WHERE
A.col1 = B.col1
AND
A.col2 = B.col2
);

Use RANK to delete duplicate rows

This is an example of the RANK function to identify and remove duplicate rows from Oracle tables, which deletes all duplicate rows while leaving the initial instance of the duplicate row:

One of the most important features of Oracle is the ability to detect and remove duplicate rows from a table. While many Oracle DBA place primary key referential integrity constraints on a table, many shops do not use RI because they need the flexibility.

Use self-join to delete duplicate rows

The most effective way to detect duplicate rows is to join the table against itself as shown below.

select
book_unique_id,
page_seq_nbr,
image_key
from
page_image a
where
rowid >
(select min(rowid) from page_image b
where
b.key1 = a.key1
and
b.key2 = a.key2
and
b.key3 = a.key3
);

Delete Duplicate Records In Sql

Please note that you must specify all of the columns that make the row a duplicate in the SQL where clause. Once you have detected the duplicate rows, you may modify the SQL statement to remove the duplicates as shown below:

How To Delete Duplicates In Oracle Sql

Oracle Delete Select

delete from
table_name a
where
a.rowid >
any (select b.rowid
from
table_name b
where
a.col1 = b.col1
and
a.col2 = b.col2
)
;

How To Delete Duplicates In Oracle

Use analytics to delete duplicate rows

You can also detect and delete duplicate rows using Oracle analytic functions:

Oracle Delete Sql

delete from
customer
where rowid in
(select rowid from
(select
rowid,
row_number()
over
(partition by custnbr order by custnbr) dup
from customer)
where dup > 1);

How To Delete Duplicates In Oracle

As we see, there are several ways to detect and delete duplicate rows from Oracle tables