BOOL_XOR

描述

对表达式中所有非 NULL 值执行逻辑异或（XOR）聚合计算。

别名

• BOOLXOR_AGG

语法

BOOL_XOR(<expr>)

参数

参数	说明
<expr>	参与逻辑异或（XOR）聚合的表达式。支持布尔类型，及可按 0/非 0 规则转换为布尔值的数值类型（0 为 FALSE，非 0 为 TRUE）

返回值

返回值为 BOOLEAN。当所有非 NULL 值仅有一个 TRUE 时返回 TRUE, 否则返回 FALSE。

如果表达式中所有的值都为 NULL 或表达式为空，则返回 NULL。

举例

初始化表：

CREATE TABLE IF NOT EXISTS test_boolean_agg (
     id INT,
     c1 BOOLEAN,
     c2 BOOLEAN,
     c3 BOOLEAN,
     c4 BOOLEAN
) DISTRIBUTED BY HASH(id) BUCKETS 1
PROPERTIES ("replication_num" = "1"); 

INSERT INTO test_boolean_agg (id, c1, c2, c3, c4) values 
(1, true, true, true, false),
(2, true, false, false, false),
(3, true, true, false, false),
(4, true, false, false, false);

聚合函数

SELECT BOOLXOR_AGG(c1), BOOLXOR_AGG(c2), BOOLXOR_AGG(c3), BOOLXOR_AGG(c4)
FROM test_boolean_agg;

+-----------------+-----------------+-----------------+-----------------+
| BOOLXOR_AGG(c1) | BOOLXOR_AGG(c2) | BOOLXOR_AGG(c3) | BOOLXOR_AGG(c4) |
+-----------------+-----------------+-----------------+-----------------+
|               0 |               0 |               1 |               0 |
+-----------------+-----------------+-----------------+-----------------+

bool_xor也可以接受数值类型的参数，如果数值不为 0，则将其转为 TRUE

CREATE TABLE test_numeric_and_null (
    id INT,
    c_int INT,
    c_float FLOAT,
    c_decimal DECIMAL(10,2),
    c_bool BOOLEAN
) DISTRIBUTED BY HASH(id) BUCKETS 1
PROPERTIES ("replication_num" = "1");

INSERT INTO test_numeric_and_null (id, c_int, c_float, c_decimal, c_bool) VALUES
(1, 1, 1.0, NULL, NULL),
(2, 0, NULL, 0.00, NULL),
(3, 1, 3.14, 1.00, NULL),
(4, 0, 1.0, 0.00, NULL),
(5, NULL, NULL, NULL, NULL);

SELECT
    BOOL_XOR(c_int) AS bool_xor_int,
    BOOL_XOR(c_float) AS bool_xor_float,
    BOOL_XOR(c_decimal) AS bool_xor_decimal,
    BOOL_XOR(c_bool) AS bool_xor_bool
FROM test_numeric_and_null;

+--------------+----------------+------------------+---------------+
| bool_xor_int | bool_xor_float | bool_xor_decimal | bool_xor_bool |
+--------------+----------------+------------------+---------------+
|            0 |              0 |                1 |          NULL |
+--------------+----------------+------------------+---------------+

窗口函数

下例按条件 (id > 2) 对行进行分区，将其划分为两组并展示窗口聚合结果：

SELECT * FROM test_boolean_agg;

+------+------+------+------+------+
| id   | c1   | c2   | c3   | c4   |
+------+------+------+------+------+
|    1 |    1 |    1 |    1 |    0 |
|    2 |    1 |    0 |    0 |    0 |
|    3 |    1 |    1 |    0 |    0 |
|    4 |    1 |    0 |    0 |    0 |
+------+------+------+------+------+

SELECT
    id,
    BOOLXOR_AGG(c1) OVER (PARTITION BY (id > 2)) AS a,
    BOOLXOR_AGG(c2) OVER (PARTITION BY (id > 2)) AS b,
    BOOLXOR_AGG(c3) OVER (PARTITION BY (id > 2)) AS c,
    BOOLXOR_AGG(c4) OVER (PARTITION BY (id > 2)) AS d
FROM test_boolean_agg
ORDER BY id;

+------+------+------+------+------+
| id   | a    | b    | c    | d    |
+------+------+------+------+------+
|    1 |    0 |    1 |    1 |    0 |
|    2 |    0 |    1 |    1 |    0 |
|    3 |    0 |    1 |    0 |    0 |
|    4 |    0 |    1 |    0 |    0 |
+------+------+------+------+------+

错误示例:

SELECT BOOL_XOR('invalid type');

ERROR 1105 (HY000): errCode = 2, detailMessage = bool_xor requires a boolean or numeric argument