What is INSERT on duplicate key update?

What is INSERT on duplicate key update?

INSERT ON DUPLICATE KEY UPDATE is a MariaDB/MySQL extension to the INSERT statement that, if it finds a duplicate unique or primary key, will instead perform an UPDATE. The row/s affected value is reported as 1 if a row is inserted, and 2 if a row is updated, unless the API’s CLIENT_FOUND_ROWS flag is set.

How do you update duplicate records in Oracle?

update test_dup set done = ‘error’ where (acc_num,tel_num, imsi) in (select acc_num, tel_num, imsi from test_dup group by acc_num, tel_num, imsi having count(acc_num) > 1); Then it updates 5 rows i.e. all duplicate rows except non-dups.

How can we prevent duplicate INSERT in Oracle?

Best Answer

  1. Create a VIEW for your table ( SELECT * FROM MyTable);
  2. Create an INSTEAD-OF INSERT trigger ON the view that does the insert.
  3. Create an UNIQUE INDEX “MyUniqueIndexName” on the columns you need to avoid duplicates.
  4. Use the following EXCEPTION section on the TRIGGER:

How can I delete duplicate records from a table without distinct clause in Oracle?

Use the rowid pseudocolumn. DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); Where column1 , column2 , and column3 make up the identifying key for each record. You might list all your columns.

How can we delete duplicate rows in Oracle without using Rowid?

Comments

  1. Put duplicates in a temp table. Create Table silly_dups as. Select * From evil_table. Group By col1, col2, col3…. Having count(*) > 1;
  2. Remove duplicates from table. Delete From evil_table. where (col1, col2, col3…) in. (Select col1, col2, col3. From silly_dups);
  3. Put duplicate rows back.

How do I find duplicates before insert?

  1. Form your initial insertion query, such as “INSERT INTO your_table ( column1 , column2 ) VALUES (‘1′,’a’);”
  2. Alter the query by adding a rule for what to do if a duplicate key is found, such as “INSERT INTO your_table ( column1 , column2 ) VALUES (‘1′,’a’) ON DUPLICATE KEY UPDATE column1 =’1′, column2 =’a’;”

How do you prevent duplicate records in SQL?

5 Easy Ways to Handle Duplicates Using SQL INSERT INTO SELECT

  1. Using INSERT INTO SELECT DISTINCT. The first option for how to identify SQL records in SQL is to use DISTINCT in your SELECT.
  2. Using WHERE NOT IN. Next, we populate the PastaDishes table.
  3. Using WHERE NOT EXISTS.
  4. Using IF NOT EXISTS.
  5. Using COUNT(*) = 0.

How do you resolve ORA 00001 unique constraint violated?

There are a few solutions to the “ORA-00001 unique constraint violated” error:

  1. Change your SQL so that the unique constraint is not violated.
  2. Change the constraint to allow for duplicate values.
  3. Drop the constraint from the column.
  4. Disable the unique constraint.

What is the difference between insert and update?

Insert is for adding data to the table, update is for updating data that is already in the table.

How do I delete duplicate records from a table with keeping one copy in Oracle?

colname3=s. colname3 etc) like this you can do for all columns. It will delete all duplicate rows and keep one original record. Create a temp table with distinct record from master table then delete from master table then again insert from temp table.

How can I delete duplicate rows in Oracle without primary key?

How can I delete duplicate rows in Oracle without distinct?

Below are alternate solutions :

  1. Remove Duplicates Using Row_Number. WITH CTE (Col1, Col2, Col3, DuplicateCount) AS ( SELECT Col1, Col2, Col3, ROW_NUMBER() OVER(PARTITION BY Col1, Col2, Col3 ORDER BY Col1) AS DuplicateCount FROM MyTable ) SELECT * from CTE Where DuplicateCount = 1.
  2. Remove Duplicates using group By.

Does Oracle have on duplicate key update?

Oracle doesn’t have on duplicate key update Use MERGE instead: Not the answer you’re looking for? Browse other questions tagged sql oracle upsert or ask your own question.

What is the effect of on duplicate key update clause?

If you specify an ON DUPLICATE KEY UPDATE clause and a row to be inserted would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row occurs. For example, if column a is declared as UNIQUE and contains the value 1, the following two statements have similar effect:

Can I use onDon duplicate key update on a partitioned table?

ON DUPLICATE KEY UPDATE on a partitioned table using a storage engine such as MyISAM that employs table-level locks locks any partitions of the table in which a partitioning key column is updated. (This does not occur with tables using storage engines such as InnoDB that employ row-level locking.)