MERGE in Many Languages

Lukas Eder takes a look at the MERGE statement in SQL:

A few dialects support MERGE. Among the ones that jOOQ 3.13 supports, there are at least:

– Db2
– Derby
– Firebird
– H2
– HSQLDB
– Oracle
– SQL Server
– Sybase SQL Anywhere
– Teradata
– Vertica

For once, regrettably, this list does not include PostgreSQL. But even the dialects in this list do not all agree on what MERGE really is. The SQL standard specifies 3 features, each one optional:

– F312 MERGE statement
– F313 Enhanced MERGE statement
– F314 MERGE statement with DELETE branch

But instead of looking at the standards and what they require, let’s look at what the dialects offer, and how it can be emulated if something is not available.

This is a really cool overview of an area where several vendors can claim support, but that support can mean quite different things. The one caveat is, I don’t know if any of the other platforms’ MERGE operators are as busted as SQL Server’s in terms of bugs.