日期:2014-05-16 浏览次数:20370 次
student subject grade --------------------------- student1 语文 80 student1 数学 70 student1 英语 60 student2 语文 90 student2 数学 80 student2 英语 100 …… 转换为 语文 数学 英语 student1 80 70 60 student2 90 80 100 …… 语句如下: select student,sum(decode(subject,'语文', grade,null)) "语文", sum(decode(subject,'数学', grade,null)) "数学", sum(decode(subject,'英语', grade,null)) "英语" from table group by student
2、动态的行列转换需要通过存储过程拼接sql语句
如:
CREATE OR REPLACE PROCEDURE GET_INSPECT_ITEM ( P_INSPECT_ID IN VARCHAR2 ,Re_CURSOR OUT SYS_REFCURSOR ) AS SQLSTR VARCHAR2 (4000); BEGIN DECLARE CURSOR C_CURSOR IS SELECT DISTINCT QCITEM_NAME FROM REP_INSPECT_ITEM WHERE INSPECT_ID=P_INSPECT_ID; c_row C_CURSOR %ROWTYPE; BEGIN SQLSTR:='SELECT INSPECT_ID,SAMPLE_ID'; FOR c_row IN C_CURSOR LOOP SQLSTR:=SQLSTR||', MAX(DECODE(T.QCITEM_NAME,''' ||c_row.QCITEM_NAME||''',T.VALUE,null)) AS "' || c_row.QCITEM_NAME || '"'; END LOOP; SQLSTR:=SQLSTR||'FROM REP_INSPECT_ITEM T GROUP BY SAMPLE_ID,INSPECT_ID HAVING INSPECT_ID='||P_INSPECT_ID; OPEN Re_CURSOR FOR SQLSTR ; END; END GET_INSPECT_ITEM;