decode (key) function
Applies to:  Databricks SQL 
 Databricks Runtime
Returns the value matching the key.
Syntax
decode(expr, { key1, value1 } [, ...] [, defValue])
Arguments
- expr: Any expression of a comparable type.
- keyN: An expression that matched the type of- expr.
- valueN: An expression that shares a least common type with- defValueand the other- valueNs.
- defValue: An optional expression that shares a least common type with- valueN.
Returns
The result is of the least common type of the valueN and defValue.
The function returns the first valueN for which keyN matches expr.
For this function NULL matches NULL.
If no keyN matches expr, defValue is returned if it exists.
If no defValue was specified the result is NULL.
Examples
SQL
> SELECT decode(5, 6, 'Spark', 5, 'SQL', 4, 'rocks');
 SQL
> SELECT decode(NULL, 6, 'Spark', NULL, 'SQL', 4, 'rocks');
 SQL
> SELECT decode(7, 6, 'Spark', 5, 'SQL', 'rocks');
 rocks