PostgreSQL Upsert on Conflict

1. Does PostgreSQL have Upsert?
2. Does Postgres update conflict?
3. What is needed for an insert on conflict update to work?
4. How do you insert if row does not exist Upsert in Postgres?
5. What is merge in PostgreSQL?
6. How do I add unique values in PostgreSQL?
7. How do I stop inserting duplicate records in PostgreSQL?
8. How do I add multiple values in PostgreSQL?
9. What is exclusion constraint?
10. Do Update Set multiple columns?
11. What does insert into return?
12. How do I Upsert in MySQL?

Does PostgreSQL have Upsert?

Introduction to the PostgreSQL upsert

In relational databases, the term upsert is referred to as merge. 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.

Does Postgres update conflict?

In PostgreSQL 9.5, the ON CONFLICT clause was added to INSERT. This lets application developers write less code and do more work in SQL. Another common usage is to insert a row if it does not exist, and update the value, if it does. This can be done with the ON CONFLICT..DO UPDATE clause.

What is needed for an insert on conflict update to work?

You must have INSERT privilege on a table in order to insert into it. If ON CONFLICT DO UPDATE is present, UPDATE privilege on the table is also required. If a column list is specified, you only need INSERT privilege on the listed columns.

How do you insert if row does not exist Upsert in Postgres?

Here is a generic python function that given a tablename, columns and values, generates the upsert equivalent for postgresql.
...

1. Create temporary table. See docs here. ...
2. INSERT Data into temp table. INSERT INTO temp_data(name, name_slug, status);
3. Add any indexes to the temp table.
4. Do main table insert.

What is merge in PostgreSQL?

MERGE performs at most one action on rows from the target table, driven by the rows from the source query. This provides a way to specify a single SQL statement that can conditionally UPDATE or INSERT rows, a task that would otherwise require multiple procedural language statements.

How do I add unique values in PostgreSQL?

You need to join against the table, or use WHERE NOT EXISTS (SELECT 1 FROM mytable WHERE ...) to make the INSERT INTO ... SELECT ... 's SELECT part return zero rows if the row already exists in the target table.

How do I stop inserting duplicate records in PostgreSQL?

If it is unacceptable for you to have errors or if you want to insert multiple records in a single insert without having to care which one violates the UNIQUE constraint, the correct syntax is to use the ON CONFLICT clause. Of course, this will also allow you to have the RETURNING clause in the same query.

How do I add multiple values in PostgreSQL?

PostgreSQL INSERT Multiple Rows

1. First, specify the name of the table that you want to insert data after the INSERT INTO keywords.
2. Second, list the required columns or all columns of the table in parentheses that follow the table name.
3. Third, supply a comma-separated list of rows after the VALUES keyword.

What is exclusion constraint?

Exclusion Constraints. Exclusion constraints ensure that if any two rows are compared on the specified columns or expressions using the specified operators, at least one of these operator comparisons will return false or null.

Do Update Set multiple columns?

To update multiple columns use the SET clause to specify additional columns. Just like with the single columns you specify a column and its new value, then another set of column and values.

What does insert into return?

INSERT inserts new rows into a table. One can insert one or more rows specified by value expressions, or zero or more rows resulting from a query.

How do I Upsert in MySQL?

UPSERT using INSERT ON DUPLICATE KEY UPDATE

1. INSERT INTO table (column_names)
2. VALUES (data)
3. ON DUPLICATE KEY UPDATE.
4. column1 = expression, column2 = expression...;