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Version: 2.5

bit_shift_left

Description​

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​

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.

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​