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21 lines
735 B
Markdown
21 lines
735 B
Markdown
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<a name="special_data_type-nothing"></a>
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# Nothing
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The only purpose of this data type is to represent [NULL](../../query_language/syntax.md#null-literal), i.e., no value.
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You can't create a `Nothing` type value, because it is used where a value is not expected. For example, `NULL` is written as `Nullable(Nothing)` ([Nullable](../../data_types/nullable.md#data_type-nullable) — this is the data type that allows storing `NULL` in tables.) The `Nothing` type is also used to denote empty arrays:
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```bash
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:) SELECT toTypeName(Array())
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SELECT toTypeName([])
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┌─toTypeName(array())─┐
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│ Array(Nothing) │
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└─────────────────────┘
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1 rows in set. Elapsed: 0.062 sec.
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```
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