Altering a column: null to not null

Question

I have a table that has several nullable integer columns. This is undesirable for several reasons, so I am looking to update all nulls to 0 and then set these columns to `NOT NULL`. Aside from changing nulls to `0`, data must be preserved. I am looking for the specific SQL syntax to alter a column (call it `ColumnA`) to "`not null`". Assume the data has been updated to not contain nulls. Using SQL server 2000.

Accepted Answer

First, make all current `NULL` values disappear:

```
UPDATE [Table] SET [Column]=0 WHERE [Column] IS NULL
```

Then, update the table definition to disallow "NULLs":

```
ALTER TABLE [Table] ALTER COLUMN [Column] INTEGER NOT NULL
```

Altering a column: null to not null

Solution

Problem