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203 lines
3.9 KiB
Markdown
203 lines
3.9 KiB
Markdown
# Bit functions
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Bit functions work for any pair of types from UInt8, UInt16, UInt32, UInt64, Int8, Int16, Int32, Int64, Float32, or Float64.
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The result type is an integer with bits equal to the maximum bits of its arguments. If at least one of the arguments is signed, the result is a signed number. If an argument is a floating-point number, it is cast to Int64.
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## bitAnd(a, b)
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## bitOr(a, b)
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## bitXor(a, b)
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## bitNot(a)
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## bitShiftLeft(a, b)
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## bitShiftRight(a, b)
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## bitRotateLeft(a, b)
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## bitRotateRight(a, b)
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## bitTest {#bittest}
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Takes any integer and converts it into [binary form](https://en.wikipedia.org/wiki/Binary_number), returns the value of a bit at specified position. The countdown starts from 0 from the right to the left.
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**Syntax**
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```sql
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SELECT bitTest(number, index)
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```
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**Parameters**
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- `number` – integer number.
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- `index` – position of bit.
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**Returned values**
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Returns a value of bit at specified position.
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Type: `UInt8`.
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**Example**
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For example, the number 43 in base-2 (binary) numeral system is 101011.
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Query:
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```sql
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SELECT bitTest(43, 1)
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```
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Result:
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```text
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┌─bitTest(43, 1)─┐
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│ 1 │
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└────────────────┘
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```
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Another example:
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Query:
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```sql
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SELECT bitTest(43, 2)
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```
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Result:
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```text
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┌─bitTest(43, 2)─┐
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│ 0 │
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└────────────────┘
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```
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## bitTestAll {#bittestall}
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Returns result of [logical conjuction](https://en.wikipedia.org/wiki/Logical_conjunction) (AND operator) of all bits at given positions. The countdown starts from 0 from the right to the left.
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The conjuction for bitwise operations:
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0 AND 0 = 0
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0 AND 1 = 0
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1 AND 0 = 0
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1 AND 1 = 1
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**Syntax**
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```sql
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SELECT bitTestAll(number, index1, index2, index3, index4, ...)
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```
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**Parameters**
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- `number` – integer number.
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- `index1`, `index2`, `index3`, `index4` – positions of bit. For example, for set of positions (`index1`, `index2`, `index3`, `index4`) is true if and only if all of its positions are true (`index1` ⋀ `index2`, ⋀ `index3` ⋀ `index4`).
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**Returned values**
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Returns result of logical conjuction.
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Type: `UInt8`.
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**Example**
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For example, the number 43 in base-2 (binary) numeral system is 101011.
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Query:
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```sql
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SELECT bitTestAll(43, 0, 1, 3, 5)
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```
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Result:
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```text
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┌─bitTestAll(43, 0, 1, 3, 5)─┐
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│ 1 │
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└────────────────────────────┘
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```
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Another example:
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Query:
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```sql
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SELECT bitTestAll(43, 0, 1, 3, 5, 2)
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```
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Result:
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```text
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┌─bitTestAll(43, 0, 1, 3, 5, 2)─┐
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│ 0 │
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└───────────────────────────────┘
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```
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## bitTestAny {#bittestany}
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Returns result of [logical disjunction](https://en.wikipedia.org/wiki/Logical_disjunction) (OR operator) of all bits at given positions. The countdown starts from 0 from the right to the left.
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The disjunction for bitwise operations:
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0 OR 0 = 0
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0 OR 1 = 1
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1 OR 0 = 1
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1 OR 1 = 1
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**Syntax**
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```sql
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SELECT bitTestAny(number, index1, index2, index3, index4, ...)
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```
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**Parameters**
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- `number` – integer number.
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- `index1`, `index2`, `index3`, `index4` – positions of bit.
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**Returned values**
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Returns result of logical disjuction.
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Type: `UInt8`.
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**Example**
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For example, the number 43 in base-2 (binary) numeral system is 101011.
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Query:
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```sql
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SELECT bitTestAny(43, 0, 2)
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```
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Result:
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```text
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┌─bitTestAny(43, 0, 2)─┐
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│ 1 │
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└──────────────────────┘
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```
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Another example:
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Query:
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```sql
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SELECT bitTestAny(43, 4, 2)
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```
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Result:
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```text
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┌─bitTestAny(43, 4, 2)─┐
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│ 0 │
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└──────────────────────┘
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```
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[Original article](https://clickhouse.yandex/docs/en/query_language/functions/bit_functions/) <!--hide-->
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