coalesce() returns the first non-null value in the given list of expressions.
Syntax: coalesce(expression [, expression]*)
Returns: The type of the value returned will be that of the first non-null expression.
Arguments
| Name | Description |
| expression | An expression which may return null. |
Example
RETURN coalesce(null, 3, 7, null, 2)
The value returned will be the first non-null expression among all the expressions passed to the function, which in this case will be 3.
Considerations
coalesce(null)returnsnull.nullwill be returned if all the arguments arenull.
Example
RETURN coalesce(2, null, "Hello, World!", true, -1, 2020)
Returns the following Result
coalesce(2, null, "Hello, World!", true, -1, 2020) |
2 |
Example
RETURN coalesce(null, "Hello, World!", true, -1, 2020, 2)
Returns the following Result
coalesce(null, "Hello, World!", true, -1, 2020, 2) |
"Hello, World!" |
Example
RETURN coalesce(null, null, true, -1, 2020, 2)
Returns the following Result
coalesce(null, null, true, -1, 2020, 2) |
true |
Example
RETURN coalesce("Hello, World!")
Returns the following Result
coalesce("Hello, World!") |
"Hello, World!" |
Example
MATCH (a)
WHERE a.name="Narendra Modi"
RETURN coalesce(a.age, a.DOB)
Returns the value of age of Narendra Modi if it is not null, or else it returns the value of DOB if it is not null, else it returns null. Considering that the age of Narendra Modi is not null, the following Result is returned.
coalesce(a.age, a.DOB) |
69 |
Example
RETURN coalesce(null, null, null, null, null, null)
Returns the following Result
coalesce(null, null, null, null, null, null) |
null |
Example
RETURN coalesce(null)
Returns the following Result
coalesce(null) |
null |
Note-This is just a special case of the above example where all values are null.