DB2根据映射表映射出结果

Posted 2020-10-02 奔跑的金鱼

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！