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196 lines
5.8 KiB
Markdown
196 lines
5.8 KiB
Markdown
---
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slug: /en/sql-reference/functions/logical-functions
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sidebar_position: 37
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sidebar_label: Logical
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---
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# Logical Functions
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Performs logical operations on arguments of any numeric types, but returns a [UInt8](../../sql-reference/data-types/int-uint.md) number equal to 0, 1 or `NULL` in some cases.
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Zero as an argument is considered `false`, while any non-zero value is considered `true`.
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## and
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Calculates the result of the logical conjunction between two or more values. Corresponds to [Logical AND Operator](../../sql-reference/operators/index.md#logical-and-operator).
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**Syntax**
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``` sql
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and(val1, val2...)
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```
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You can use the [short_circuit_function_evaluation](../../operations/settings/settings.md#short-circuit-function-evaluation) setting to calculate the `and` function according to a short scheme. If this setting is enabled, `vali` is evaluated only on rows where `(val1 AND val2 AND ... AND val{i-1})` is true. For example, an exception about division by zero is not thrown when executing the query `SELECT and(number = 2, intDiv(1, number)) FROM numbers(10)`.
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**Arguments**
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- `val1, val2, ...` — List of at least two values. [Int](../../sql-reference/data-types/int-uint.md), [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Nullable](../../sql-reference/data-types/nullable.md).
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**Returned value**
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- `0`, if there is at least one zero value argument.
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- `NULL`, if there are no zero values arguments and there is at least one `NULL` argument.
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- `1`, otherwise.
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Type: [UInt8](../../sql-reference/data-types/int-uint.md) or [Nullable](../../sql-reference/data-types/nullable.md)([UInt8](../../sql-reference/data-types/int-uint.md)).
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**Example**
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Query:
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``` sql
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SELECT and(0, 1, -2);
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```
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Result:
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``` text
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┌─and(0, 1, -2)─┐
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│ 0 │
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└───────────────┘
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```
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With `NULL`:
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``` sql
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SELECT and(NULL, 1, 10, -2);
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```
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Result:
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``` text
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┌─and(NULL, 1, 10, -2)─┐
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│ ᴺᵁᴸᴸ │
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└──────────────────────┘
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```
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## or
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Calculates the result of the logical disjunction between two or more values. Corresponds to [Logical OR Operator](../../sql-reference/operators/index.md#logical-or-operator).
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**Syntax**
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``` sql
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or(val1, val2...)
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```
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You can use the [short_circuit_function_evaluation](../../operations/settings/settings.md#short-circuit-function-evaluation) setting to calculate the `or` function according to a short scheme. If this setting is enabled, `vali` is evaluated only on rows where `((NOT val1) AND (NOT val2) AND ... AND (NOT val{i-1}))` is true. For example, an exception about division by zero is not thrown when executing the query `SELECT or(number = 0, intDiv(1, number) != 0) FROM numbers(10)`.
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**Arguments**
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- `val1, val2, ...` — List of at least two values. [Int](../../sql-reference/data-types/int-uint.md), [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Nullable](../../sql-reference/data-types/nullable.md).
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**Returned value**
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- `1`, if there is at least one non-zero value.
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- `0`, if there are only zero values.
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- `NULL`, if there are only zero values and `NULL`.
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Type: [UInt8](../../sql-reference/data-types/int-uint.md) or [Nullable](../../sql-reference/data-types/nullable.md)([UInt8](../../sql-reference/data-types/int-uint.md)).
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**Example**
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Query:
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``` sql
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SELECT or(1, 0, 0, 2, NULL);
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```
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Result:
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``` text
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┌─or(1, 0, 0, 2, NULL)─┐
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│ 1 │
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└──────────────────────┘
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```
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With `NULL`:
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``` sql
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SELECT or(0, NULL);
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```
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Result:
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``` text
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┌─or(0, NULL)─┐
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│ ᴺᵁᴸᴸ │
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└─────────────┘
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```
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## not
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Calculates the result of the logical negation of the value. Corresponds to [Logical Negation Operator](../../sql-reference/operators/index.md#logical-negation-operator).
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**Syntax**
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``` sql
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not(val);
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```
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**Arguments**
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- `val` — The value. [Int](../../sql-reference/data-types/int-uint.md), [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Nullable](../../sql-reference/data-types/nullable.md).
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**Returned value**
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- `1`, if the `val` is `0`.
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- `0`, if the `val` is a non-zero value.
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- `NULL`, if the `val` is a `NULL` value.
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Type: [UInt8](../../sql-reference/data-types/int-uint.md) or [Nullable](../../sql-reference/data-types/nullable.md)([UInt8](../../sql-reference/data-types/int-uint.md)).
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**Example**
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Query:
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``` sql
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SELECT NOT(1);
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```
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Result:
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``` test
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┌─not(1)─┐
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│ 0 │
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└────────┘
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```
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## xor
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Calculates the result of the logical exclusive disjunction between two or more values. For more than two values the function works as if it calculates `XOR` of the first two values and then uses the result with the next value to calculate `XOR` and so on.
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**Syntax**
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``` sql
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xor(val1, val2...)
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```
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**Arguments**
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- `val1, val2, ...` — List of at least two values. [Int](../../sql-reference/data-types/int-uint.md), [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Nullable](../../sql-reference/data-types/nullable.md).
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**Returned value**
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- `1`, for two values: if one of the values is zero and other is not.
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- `0`, for two values: if both values are zero or non-zero at the same time.
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- `NULL`, if there is at least one `NULL` value.
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Type: [UInt8](../../sql-reference/data-types/int-uint.md) or [Nullable](../../sql-reference/data-types/nullable.md)([UInt8](../../sql-reference/data-types/int-uint.md)).
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**Example**
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Query:
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``` sql
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SELECT xor(0, 1, 1);
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```
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Result:
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``` text
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┌─xor(0, 1, 1)─┐
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│ 0 │
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└──────────────┘
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```
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