In this tutorial, you have learned about the PostgreSQL upsert feature using the INSERT ON CONFLICT statement. The following statement verifies the upsert: Suppose, you want to concatenate the new email with the old email when inserting a customer that already exists, in this case, you use the UPDATE clause as the action of the INSERT statement as follows: INSERT INTO customers ( name, email)ĭO UPDATE SET email = EXCLUDED.email || ' ' || customers.email Code language: SQL (Structured Query Language) ( sql ) The following statement is equivalent to the above statement but it uses the name column instead of the unique constraint name as the target of the INSERT statement. It returns the following output: As clearly shown in the output, the names and data types of the actionfilm table are derived from the columns of the SELECT clause. The statement specified that if the customer name exists in the customers table, just ignore it (do nothing). VALUES( 'Microsoft', CONFLICT ON CONSTRAINT customers_name_keyĭO NOTHING Code language: SQL (Structured Query Language) ( sql ) Suppose Microsoft changes the contact email from to we can update it using the UPDATE statement. However, to demonstrate the upsert feature, we use the following INSERT ON CONFLICT statement: INSERT INTO customers ( NAME, email) ( 'IBM', 'Microsoft', 'Intel', Code language: SQL (Structured Query Language) ( sql ) The following INSERT statement inserts some rows into the customers table. The name column has a unique constraint to guarantee the uniqueness of customer names. The customers table consists of four columns: customer_id, name, email, and active. ) Code language: SQL (Structured Query Language) ( sql ) The following statement creates a new table called customers to demonstrate the PostgreSQL upsert feature. If you are also working with MySQL, you will find that the upsert feature is similar to the insert on duplicate key update statement in MySQL. If you are using an earlier version, you will need a workaround to have the upsert feature. Notice that the ON CONFLICT clause is only available from PostgreSQL 9.5. WHERE condition – update some fields in the table.
DO NOTHING – means do nothing if the row already exists in the table.
WHERE predicate – a WHERE clause with a predicate. psql dbtest SELECT dblinkexec ( 'dbnamepostgres', 'INSERT INTO tbla SELECT id, time FROM dblink ( ''dbnamedbtest'', ''SELECT id, time FROM tblb'' ) AS t (id integer, time integer) WHERE time > 1000 ' ) I don't like that nested dblink, but AFAIK I can't reference to tblB in dblinkexec body.ON CONSTRAINT constraint_name – where the constraint name could be the name of the UNIQUE constraint.In this statement, the target can be one of the following: PostgreSQL added the ON CONFLICT target action clause to the INSERT statement to support the upsert feature. ON CONFLICT target action Code language: SQL (Structured Query Language) ( sql ) To use the upsert feature in PostgreSQL, you use the INSERT ON CONFLICT statement as follows: INSERT INTO table_name(column_list) That is why we call the action is upsert (the combination of update or insert).
The idea is that when you insert a new row into the table, PostgreSQL will update the row if it already exists, otherwise, it will insert the new row. In relational databases, the term upsert is referred to as merge. Summary: in this tutorial, you will learn how to use PostgreSQL upsert feature to insert or update data if the row that is being inserted already exists in the table.