Shifts a value left by a specific number of places (<<). This function is an additional function of MaxCompute V2.0.
Syntax
int shiftleft(tinyint|smallint|int <number1>, int <number2>)
bigint shiftleft(bigint <number1>, int <number2>)Parameters
number1: required. The value is of the TINYINT, SMALLINT, INT, or BIGINT type.
number2: required. The value is of the INT type.
Return value
A value of the INT or BIGINT type is returned. The return value varies based on the following rules:
If number1 is not of the TINYINT, SMALLINT, INT, or BIGINT type, an error is returned.
If number2 is not of the INT type, an error is returned.
If the value of number1 or number2 is null, null is returned.
Sample data
This section provides sample source data and examples for you to understand how to use the functions. In this topic, a table named mf_math_fun_t is created and data is inserted into the table. Sample statements:
create table if not exists mf_math_fun_t(
int_data int,
bigint_data bigint,
double_data double,
decimal_data decimal,
float_data float,
string_data string
);
insert into mf_math_fun_t values
(null, -10, 0.525, 0.525BD, cast(0.525 as float), '10'),
(-20, null, -0.1, -0.1BD, cast(-0.1 as float), '-10'),
(0, -1, null, 20.45BD, cast(-1 as float), '30'),
(-40, 4, 0.89, null, cast(0.89 as float), '-30'),
(5, -50, -1, -1BD, null, '50'),
(-60, 6, 1.5, 1.5BD, cast(1.5 as float), '-50'),
(-1, -70, -7.5, -7.5BD, cast(-7.5 as float),null ),
(-80, 1, -10.2, -10.2BD, cast(-10.2 as float), '-1' ),
(9, -90, 2.58, 2.58BD, cast(2.58 as float), '0'),
(-100, 10, -5.8, -5.8BD, cast(-5.8 as float), '-90');Query data from the mf_math_fun_t table. Sample statement:
select * from mf_math_fun_t;
-- The following result is returned:
+------------+-------------+-------------+--------------+------------+-------------+
| int_data | bigint_data | double_data | decimal_data | float_data | string_data |
+------------+-------------+-------------+--------------+------------+-------------+
| NULL | -10 | 0.525 | 0.525 | 0.525 | 10 |
| -20 | NULL | -0.1 | -0.1 | -0.1 | -10 |
| 0 | -1 | NULL | 20.45 | -1.0 | 30 |
| -40 | 4 | 0.89 | NULL | 0.89 | -30 |
| 5 | -50 | -1.0 | -1 | NULL | 50 |
| -60 | 6 | 1.5 | 1.5 | 1.5 | -50 |
| -1 | -70 | -7.5 | -7.5 | -7.5 | NULL |
| -80 | 1 | -10.2 | -10.2 | -10.2 | -1 |
| 9 | -90 | 2.58 | 2.58 | 2.58 | 0 |
| -100 | 10 | -5.8 | -5.8 | -5.8 | -90 |
+------------+-------------+-------------+--------------+------------+-------------+Example: static data
-- The return value is 4. The following statement shifts the binary value of 1 two places to the left (1<<2, 0001 shifted to 0100).
select shiftleft(1,2);
-- The return value is 32. The following statement shifts the binary value of 4 three places to the left (4<<3, 0100 shifted to 100000).
select shiftleft(4,3);
-- The return value is null.
select shiftleft(null,2);Example: table data
Shift numbers in the int_data and bigint_data columns left by a specific number of places based on the Sample data. Sample statement:
-- Enable the MaxCompute V2.0 data type edition. Commit this command along with SQL statements.
set odps.sql.type.system.odps2=true;
select shiftleft(int_data, 1) as int_new, shiftleft(bigint_data, 1) as bigint_new from mf_math_fun_t;The following result is returned:
+---------+------------+
| int_new | bigint_new |
+---------+------------+
| NULL | -20 |
| -40 | NULL |
| 0 | -2 |
| -80 | 8 |
| 10 | -100 |
| -120 | 12 |
| -2 | -140 |
| -160 | 2 |
| 18 | -180 |
| -200 | 20 |
+---------+------------+Related functions
SHIFTLEFT is a mathematical function. For more information about functions related to data computing and conversion, see Mathematical functions.