null
BigQuery
Db2 (LUW)
MariaDB
MySQL
Oracle DB
PostgreSQL
SQL Server
SQLite
2005
2007
2009
2011
2013
2015
2017
2019
2021
✓ 3.5.7 - 3.43.0
✓ 2012 - 2022
b
✓ 2008R2
✓ 9.1 - 16
b
✓ 8.4 - 9.0
⚠ 8.3
⚠ 11gR1 - 21c
a
b
✓ 5.0 - 8.0.34
✓ 5.1 - 10.11
✓ 9.7 - 11.5.8
✓ 2.0
Empty string
is null
.
||
treats
null
as empty string
concat()
treats
null
as empty string