In Oracle Database, the CASE expression compares a list of conditions and returns one of multiple possible expressions. It allows us to use IF … THEN … ELSE logic in SQL statements without having to invoke procedures.
The CASE expression is included in the SQL standard (ISO/IEC 9075), and most major RDBMSs support it.
Oracle also has a CASE statement that’s very similar to the CASE expression, but with some minor differences.
In PostgreSQL, the COALESCE() operator returns the first non-null value from its list of arguments. If all arguments are null, it returns null.
In MySQL, the CASE operator compares a list of conditions and returns one of multiple possible result expressions.
The CASE expression is included in the SQL standard (ISO/IEC 9075), and most major RDBMSs support it.
MySQL also has the CASE statement, which is slightly different to the CASE operator. This article is about the CASE operator.
In MariaDB, we can use the CASE operator to compare a list of conditions and return a different result depending on which condition (if any) is matched.
The CASE expression is included in the SQL standard (ISO/IEC 9075), and most major RDBMSs support it.
MariaDB also has the CASE statement, which is slightly different to the CASE operator. This article is about the CASE operator.
In MariaDB, the COALESCE() operator returns the first non-NULL value in the list, or NULL if there are no non-NULL values.
In MySQL, the COALESCE() operator returns the first non-NULL value in the list, or NULL if there are no non-NULL values.
In SQL Server, the COALESCE() expression returns its first non-null argument.
The way it works is, we pass a list of arguments to the expression, it evaluates the arguments in order and returns the current value of the first expression that initially doesn’t evaluate to NULL.
In SQLite, the ->> operator extracts a subcomponent from a JSON document and returns an SQL representation of that subcomponent.
The ->> operator was first introduced in SQLite version 3.38.0 (released on 22 February 2022).