nullIf
Syntax
nullIf(X, Y)
Arguments
X / Y can be a scalar or vector, or an expression that returns a scalar or vector.
Details
For two scalars, the function returns a NULL value if the values and data types of X and Y are equal. Otherwise, returns X.
For two vectors of equal length, the function conducts the aforementioned calculation with each pair of elements in X and Y at the same position.
For a scalar and a vector, the function conducts the aforementioned calculation on the scalar and each element of the vector.
Examples
$ t = table(`APPL`IBM`AMZN`IBM`APPL`AMZN as sym, 10.1 11.2 11.3 12 10.6 10.8 as val)
$ select nullIf(sym, `AMZN) from t
| nullIf_sym |
|---|
| APPL |
| IBM |
| IBM |
| APPL |
$ select * from t where nullIf(sym, `AMZN)!=NULL
| sym | val |
|---|---|
| APPL | 10.1 |
| IBM | 11.2 |
| IBM | 12 |
| APPL | 10.6 |