Sql Server Computed Column Formula syntax

Question

I want to use a computed bit column that will be true if another column in the table is not null. What's the correct formula for this? ``` HasLabel = computed column (bit) Label = varchar NULL ``` The following formula does not validate. - what am I missing? Formula for HasLabel = `Label IS NOT NULL`

Accepted Answer

A computed column must return a value, whereas you are just doing a comparison. Try this instead:

```
case when label is null then 0 else 1 end
```

SQL Server will not understand this as a non-NULLable column however. To handle that, change the computation to:

```
isnull(case when label IS NULL then 0 else 1 end, 0)
```

Sql Server Computed Column Formula syntax

Solution

Problem