postgresqlHow do I use the PostgreSQL COALESCE function?
The PostgreSQL COALESCE function is used to return the first non-null value from a list of values. It takes in any number of arguments and returns the first one that is not NULL.
Example
SELECT COALESCE(NULL, 5, 0);Output example
5The code above will return the value 5 because it is the first non-null value in the list.
The parts of the code are:
SELECT: This is the keyword used to specify that a query is being made.COALESCE: This is the function being used to return the first non-null value.NULL: This is a value that is being checked for.5: This is the value that is returned because it is the first non-null value.0: This is the last value in the list, but it is not returned because it is not the first non-null value.
For more information on the COALESCE function, please see the following link:
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