After a long time of waiting, PostgreSQL 9.5 introduced INSERT ON CONFLICT [DO UPDATE] [DO NOTHING].

This option basically helps to perform DML actions like, Insert IF not Exists, Update IF Exists.

Previously, we have to use upsert or merge statement to do this kind of operation. I have also published an article on it.

PostgreSQL: Insert – Update or Upsert – Merge using writable CTE

This newly option has two varieties:

• INSERT ON CONFLICT DO UPDATE: If record matched, it is updated with the new data value.
• INSERT ON CONFLICT DO NOTHING: If record matched, it skips the record or error.

Below is a full demonstration of this:

Create a table with sample data:

CREATE TABLE tbl_Employee
(	
	EmpID INT PRIMARY KEY
	,EmpName CHARACTER VARYING 
);

INSERT INTO tbl_Employee 
VALUES (1,'Anvesh'),(2,'Roy'),(3,'Lee')
,(4,'Nivu'),(5,'Rajesh'),(6,'Nupur');

Insert one more row with option INSERT ON CONFLICT DO UPDATE:

Using this option, if a conflict occurs then it will update the mentioned data.
Here, I have use “Excluded” table which is special table and contains the row-to-be-inserted.

INSERT INTO tbl_Employee 
VALUES (7,'Ramu')
ON CONFLICT (EmpID)
DO UPDATE SET EmpName = Excluded.EmpName;

INSERT INTO tbl_Employet 
VALUES (7,'Mahi')
ON CONFLICT (EmpID)
DO UPDATE SET EmpName = Excluded.EmpName;

INSERT INTO tbl_Employee 
VALUES (8,'Noor')
ON CONFLICT (EmpID)
DO NOTHING;

INSERT INTO tbl_Employee 
VALUES (8,'Noor')
ON CONFLICT (EmpID)
DO NOTHING;

SELECT *FROM tbl_Employee;

/*
EmpID   EmpName
-----------------
1       Anvesh
2       Roy
3       Lee
4       Nivu
5       Rajesh
6       Nupur
7       Mahi
8       Noor
*/

In this post, I am sharing a demonstration on how to skip the INSERT statement for duplicate records in MySQL.

Insert if not exists:

Basically, there are two situations for bulk insertion:

First: during insertion, if the record exists, update the old value with new the value.

This I have already posted so please visit this page.
href=”https://www.dbrnd.com/2015/08/insert-update-merge-statement-in-mysql

Second: during insertion, if the record exists, skip the new value for an insert. This I am going to explain in this post.

MySQL INSERT IGNORE statement:

Using this, you can perform actions like, “Insert if not exists”.

First, create primary data by applying proper composite unique key or primary key.
If the same key is trying to INSERT during the new insertion, INSERT IGNORE Statement only skip that transaction.

Below is a full demonstration:
I created two tables and transferring some duplicate data from one to another using INSERT IGNORE statement.

Let’s first create tables and sample data:

CREATE TABLE tbl_First
(
   ID INTEGER 
   ,Name VARCHAR(255)
);

INSERT INTO tbl_First VALUES
(1,'ABC'),(1,'LKM')
,(3,'PQR'),(4,'XYZ');

CREATE TABLE tbl_Second
(
   ID INTEGER PRIMARY KEY
   ,Name VARCHAR(255)
);

We created two tables, table first has no primary key and table second has a primary key.

You can find the duplicate key in the insert statement.

Now, first try to copy this data from the table first to the second table:

INSERT INTO tbl_Second 
SELECT *FROM tbl_First;

After executing this, You will get an error for duplicate keys.

Now, apply INSERT IGNORE Statement:

INSERT IGNORE INTO tbl_Second
SELECT *FROM tbl_First;

SELECT *FROM tbl_Second;

Result is :

You can see the result where duplicate key ignored by the insert statement.