【DB2】根据映射表映射出结果

第一步：创建语法




CREATE TABLE OLIVER_MAP(ID INT,COM_TYPE VARCHAR(100),COM_NAME VARCHAR(100),SR_UP DECIMAL(18,2),
SR_LIM DECIMAL(18,2),RES VARCHAR(100));
INSERT INTO OLIVER_MAP(ID,COM_TYPE,COM_NAME,SR_UP,SR_LIM,RES)
VALUES(1,'A1','A类小型公司',3000000,NULL,'AS');
INSERT INTO OLIVER_MAP(ID,COM_TYPE,COM_NAME,SR_UP,SR_LIM,RES)
VALUES(2,'A2','A类小型公司',3000000,NULL,'AS');
INSERT INTO OLIVER_MAP(ID,COM_TYPE,COM_NAME,SR_UP,SR_LIM,RES)
VALUES(3,'B1','B类大型公司',100000000,NULL,'BB');
INSERT INTO OLIVER_MAP(ID,COM_TYPE,COM_NAME,SR_UP,SR_LIM,RES)
VALUES(4,'B2','B类大型公司',100000000,NULL,'BB');
INSERT INTO OLIVER_MAP(ID,COM_TYPE,COM_NAME,SR_UP,SR_LIM,RES)
VALUES(5,NULL,null,null,NULL,'O');

第二步：创建测试数据进行测试

CREATE TABLE OLIVER_01(ID INT,COM_TYPE VARCHAR(100),SR DECIMAL(18,2),YQFL VARCHAR(10));
 
INSERT INTO OLIVER_01 VALUES(1,'A1',30000000,'O');
 
INSERT INTO OLIVER_01 VALUES(2,'A2',30000000,'O');
 
INSERT INTO OLIVER_01 VALUES(3,'B1',100000000,'BB');
 
INSERT INTO OLIVER_01 VALUES(4,'B2',100000000,'BB');
 
INSERT INTO OLIVER_01 VALUES(5,'C',100000000,'O');
 
INSERT INTO OLIVER_01 VALUES(6,'A1',NULL,'O');
 
INSERT INTO OLIVER_01 VALUES(7,'A2',NULL,'O');
 
INSERT INTO OLIVER_01 VALUES(8,'B1',NULL,'O');
 
INSERT INTO OLIVER_01 VALUES(9,'B2',NULL,'O');
 
INSERT INTO OLIVER_01 VALUES(10,'A1',30000001,'O');

第三步骤：查询结果

SELECT T.*
,(SELECT RES FROM OLIVER_MAP A
WHERE (A.COM_TYPE IS NULL OR A.COM_TYPE=T.COM_TYPE)
AND (A.SR_UP IS NULL OR A.SR_UP>=T.SR)
 AND (A.SR_LIM IS NULL OR A.SR_LIM<T.SR)
 ORDER BY A.ID FETCH FIRST ROW ONLY) AS RES
FROM OLIVER_01 T

OLIVER_01表数据

映射表数据

查询结构

该案例适用于存在映射表，然后根据映射表匹配得出结果！