后浪云OceanBase教程：OceanBase ORA_HASH

ORA_HASH 函数获取对应表达式的 HASH 值。

语法

ORA_HASH(expr [, max_bucket [, seed_value ] ])

参数

返回类型

NUMBER 类型数据。

示例

创建表 SALE，并向里面插入数据。执行以下语句：

CREATE TABLE SALE(MONTH CHAR(6), SELL NUMBER(10,2));
INSERT INTO SALE VALUES(200001, 1000);
INSERT INTO SALE VALUES(200002, 1100);
INSERT INTO SALE VALUES(200003, 1200);
INSERT INTO SALE VALUES(200004, 1300);
INSERT INTO SALE VALUES(200005, 1400);
INSERT INTO SALE VALUES(200006, 1500);
INSERT INTO SALE VALUES(200007, 1600);
INSERT INTO SALE VALUES(200101, 1100);
INSERT INTO SALE VALUES(200202, 1200);
INSERT INTO SALE VALUES(200301, 1300);

使用 ORA_HASH 函数查询 SALE 表，并执行以下语句：

SELECT ORA_HASH(CONCAT(month,sell),12,0), month, sell FROM Sale;

查询结果如下：

+-----------------------------------+--------+------+
| ORA_HASH(CONCAT(MONTH,SELL),12,0) | MONTH  | SELL |
+-----------------------------------+--------+------+
|                                 1 | 200001 | 1000 |
|                                 6 | 200002 | 1100 |
|                                 5 | 200003 | 1200 |
|                                 4 | 200004 | 1300 |
|                                 5 | 200005 | 1400 |
|                                 2 | 200006 | 1500 |
|                                 7 | 200007 | 1600 |
|                                10 | 200101 | 1100 |
|                                 7 | 200202 | 1200 |
|                                 4 | 200301 | 1300 |
+-----------------------------------+--------+------+