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bit_shift_left

docs/en/sql-reference/sql-functions/bit-functions/bit_shift_left.md

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bit_shift_left

Shifts the binary representation of a numeric expression to the left by a specified number of bits.

This function performs an arithmetic left shift, during which the bit length does not change, 0 is appended to the end, and the high bit remains unchanged. For example, shifting 10101 to the left by one bit results in 11010.

Syntax

Haskell
bit_shift_left(value, shift)

Parameters

value: the value or numeric expression to shift. Supported data types are TINYINT, SMALLINT, INT, BIGINT, and LARGEINT.

shift: the number of bits to shift. The supported data type is BIGINT.

Return value

Returns a value of the same type as value.

Usage notes

  • If any input parameter is NULL, NULL is returned.
  • If shift is less than 0, 0 is returned.
  • Shifting a value by 0 always results in the original value.
  • Shifting 0 by a shift always results in 0.
  • If the data type of value is numeric but not an integer, that value will be cast to an integer. See Examples.
  • If the data type of value is a string, the value will be cast to an integer if possible. If the value cannot be cast to an integer, it will be processed as NULL. See Examples.

Examples

Use this function to shift numeric values.

Plain
SELECT bit_shift_left(2, 1);
+----------------------+
| bit_shift_left(2, 1) |
+----------------------+
|                    4 |
+----------------------+

SELECT bit_shift_left(2.2, 1);
+------------------------+
| bit_shift_left(2.2, 1) |
+------------------------+
|                      4 |
+------------------------+

SELECT bit_shift_left("2", 1);
+------------------------+
| bit_shift_left('2', 1) |
+------------------------+
|                      4 |
+------------------------+

SELECT bit_shift_left(-2, 1);
+-----------------------+
| bit_shift_left(-2, 1) |
+-----------------------+
|                    -4 |
+-----------------------+

References