JOOQ“IN”查询抛出空指针异常

Question

When we try to fetch data with Null values

field(TABLE_NAME.COLUMN_NAME.in(null))

with IN clause getting null pointer exception.

Maybe because of this.

  @Override
    public final Condition in(Collection<?> values) {
        Field<?>[] fields = new Field[values.size()];

        Iterator<?> it = values.iterator();
        for (int i = 0; it.hasNext(); i++)
            fields[i] = Tools.field(it.next(), this);

        return in(fields);
    }

In the database, we can provide null in IN clause.

There is an existing "won't fix" issue in jooq https://github.com/jOOQ/jOOQ/issues/3867

There are some alternatives:

• check null before IN(Cant do in my case its a really big select statement)

So if I want to make this possible is there any other workaround.

PS: On a similar note "eq" works perfectly fine:

@Override
    public final Condition equal(Field<T> field) {
        return compare(EQUALS, nullSafe(field, getDataType()));
    }

Edit: 'field(TABLE_NAME.COLUMN_NAME.in(null))' here null is a collection.

Answer 1

Your example code doesn't compile:

TABLE_NAME.COLUMN_NAME.in(null)

There are 5 overloads of this in() method in jOOQ 3.14, and as such, you cannot pass the null literal to the in() method. Your real client code may be using a local variable like this:

Collection<?> collection = null;
TABLE_NAME.COLUMN_NAME.in(collection)

There might be a case for when this should behave the same as passing an empty collection, such as Collections.emptyList() , but this isn't what you seem to want. You probably want to pass actual null values inside of that collection, which you can do:

TABLE_NAME.COLUMN_NAME.in(1, null, 2)

But why would you do it? SQL implements three valued logic , meaning that NULL values have no effect in IN predicates, while they have an unintuitive, hardly desired effect in NOT IN predicates (the entire predicate becomes NULL )