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72 lines
2.5 KiB
Markdown
72 lines
2.5 KiB
Markdown
---
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slug: /en/sql-reference/aggregate-functions/reference/any
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sidebar_position: 102
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---
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# any
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Selects the first encountered value of a column.
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:::warning
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As a query can be executed in arbitrary order, the result of this function is non-deterministic.
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If you need an arbitrary but deterministic result, use functions [`min`](../reference/min.md) or [`max`](../reference/max.md).
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:::
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By default, the function never returns NULL, i.e. ignores NULL values in the input column.
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However, if the function is used with the `RESPECT NULLS` modifier, it returns the first value reads no matter if NULL or not.
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**Syntax**
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```sql
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any(column) [RESPECT NULLS]
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```
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Aliases `any(column)` (without `RESPECT NULLS`)
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- `any_value`
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- [`first_value`](../reference/first_value.md).
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Alias for `any(column) RESPECT NULLS`
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- `anyRespectNulls`, `any_respect_nulls`
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- `firstValueRespectNulls`, `first_value_respect_nulls`
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- `anyValueRespectNulls`, `any_value_respect_nulls`
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**Parameters**
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- `column`: The column name.
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**Returned value**
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The first value encountered.
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:::note
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The return type of the function is the same as the input, except for LowCardinality which is discarded.
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This means that given no rows as input it will return the default value of that type (0 for integers, or Null for a Nullable() column).
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You might use the `-OrNull` [combinator](../../../sql-reference/aggregate-functions/combinators.md) ) to modify this behaviour.
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:::
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**Implementation details**
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In some cases, you can rely on the order of execution.
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This applies to cases when `SELECT` comes from a subquery that uses `ORDER BY`.
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When a `SELECT` query has the `GROUP BY` clause or at least one aggregate function, ClickHouse (in contrast to MySQL) requires that all expressions in the `SELECT`, `HAVING`, and `ORDER BY` clauses be calculated from keys or from aggregate functions.
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In other words, each column selected from the table must be used either in keys or inside aggregate functions.
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To get behavior like in MySQL, you can put the other columns in the `any` aggregate function.
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**Example**
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Query:
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```sql
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CREATE TABLE tab (city Nullable(String)) ENGINE=Memory;
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INSERT INTO tab (city) VALUES (NULL), ('Amsterdam'), ('New York'), ('Tokyo'), ('Valencia'), (NULL);
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SELECT any(city), anyRespectNulls(city) FROM tab;
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```
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```response
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┌─any(city)─┬─anyRespectNulls(city)─┐
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│ Amsterdam │ ᴺᵁᴸᴸ │
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└───────────┴───────────────────────┘
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```
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