自己编写 Oracle 分页函数

 CREATE OR REPLACE PACKAGE PACK_PAGINATION AS
   PAGESIZE CONSTANT NUMBER := 2;
   TYPE TYRECORD_EMP IS RECORD(
     EMPNO    EMP.EMPNO%TYPE,
     ENAME    EMP.ENAME%TYPE,
     JOB      EMP.JOB%TYPE,
     MGR      EMP.MGR%TYPE,
     HIREDATE EMP.HIREDATE%TYPE,
     SAL      EMP.SAL%TYPE,
     COMM     EMP.COMM%TYPE,
     DEPTNO   EMP.DEPTNO%TYPE);
   TYPE RECORD_EMP IS TABLE OF TYRECORD_EMP;

   FUNCTION FUN_PAGINATION(CURRENTPAGE NUMBER) RETURN RECORD_EMP
     PIPELINED;
 END;

 CREATE OR REPLACE PACKAGE BODY PACK_PAGINATION AS
   FUNCTION FUN_PAGINATION(CURRENTPAGE NUMBER) RETURN RECORD_EMP
     PIPELINED AS
     EMP_ROW  EMP%ROWTYPE;
     REC_EMP  TYRECORD_EMP;
     COUNTNUM NUMBER;
     PAGENUM  NUMBER;
     E_EXP1 EXCEPTION;
     EXP1_STRING VARCHAR2(1000) := '输入页数过大！';
     E_EXP2 EXCEPTION;
     PRAGMA EXCEPTION_INIT(E_EXP2, -06553);
     CURSOR CURSOR_EMP IS
       SELECT EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO
         FROM (SELECT EMPNO,
                      ENAME,
                      JOB,
                      MGR,
                      HIREDATE,
                      SAL,
                      COMM,
                      DEPTNO,
                      ROWNUM RN
                 FROM EMP
                WHERE ROWNUM <= (CURRENTPAGE - 1) * PAGESIZE + PAGESIZE)
        WHERE RN > (CURRENTPAGE - 1) * PAGESIZE
        ORDER BY DEPTNO;
   BEGIN

     SELECT COUNT(1) INTO COUNTNUM FROM EMP;
     PAGENUM := COUNTNUM / PAGESIZE;
     IF CURRENTPAGE > PAGENUM THEN
       RAISE E_EXP1;
     ELSE
       OPEN CURSOR_EMP;
       LOOP
         FETCH CURSOR_EMP
           INTO EMP_ROW;
         EXIT WHEN CURSOR_EMP%NOTFOUND;
         REC_EMP.EMPNO    := EMP_ROW.EMPNO;
         REC_EMP.ENAME    := EMP_ROW.ENAME;
         REC_EMP.JOB      := EMP_ROW.JOB;
         REC_EMP.MGR      := EMP_ROW.MGR;
         REC_EMP.HIREDATE := EMP_ROW.HIREDATE;
         REC_EMP.SAL      := EMP_ROW.SAL;
         REC_EMP.COMM     := EMP_ROW.COMM;
         REC_EMP.DEPTNO   := EMP_ROW.DEPTNO;
         PIPE ROW(REC_EMP);
       END LOOP;
     END IF;
     CLOSE CURSOR_EMP;
     RETURN;
   EXCEPTION
     WHEN E_EXP1 THEN
       DBMS_OUTPUT.PUT_LINE(EXP1_STRING || '每页显示' || PAGESIZE || '条, 共计' ||
                            PAGENUM || '页!');
     WHEN E_EXP2 THEN
       DBMS_OUTPUT.PUT_LINE('触发了ORA-06553 错误！' || SQLERRM);
     WHEN OTHERS THEN
       DBMS_OUTPUT.PUT_LINE(DBMS_UTILITY.FORMAT_ERROR_STACK);
   END FUN_PAGINATION;
 END;

----代码优化 后

 --以上代码的优化 ；
 CREATE OR REPLACE PACKAGE  SPILE_PAGE AS 

   PAGESIZE NUMBER := 5;
   TYPE TYRECORD_EMP IS RECORD(
     EMPNO    EMP.EMPNO%TYPE,
     ENAME    EMP.ENAME%TYPE,
     JOB      EMP.JOB%TYPE,
     MGR      EMP.MGR%TYPE,
     HIREDATE EMP.HIREDATE%TYPE,
     SAL      EMP.SAL%TYPE,
     COMM     EMP.COMM%TYPE,
     DEPTNO   EMP.DEPTNO%TYPE);
   REC_EMP TYRECORD_EMP;
     TYPE TABLE_EMP_RECORD IS TABLE OF TYRECORD_EMP ;
     FUNCTION FUN_PAGINATION1(CURRENTPAGE NUMBER)   RETURN TABLE_EMP_RECORD
   PIPELINED ;
     END SPILE_PAGE;

 CREATE OR REPLACE PACKAGE BODY SPILE_PAGE AS
     FUNCTION  FUN_PAGINATION1(CURRENTPAGE NUMBER)
   RETURN TABLE_EMP_RECORD
   PIPELINED AS
   PAGESIZE NUMBER := 5;
   CURSOR CURSOR_EMP IS
     SELECT EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO
       FROM (SELECT E.*, ROWNUM RN
               FROM EMP E
              WHERE ROWNUM <= (CURRENTPAGE - 1) * PAGESIZE + PAGESIZE)
      WHERE RN >= (CURRENTPAGE - 1) * PAGESIZE;
 BEGIN
     --优化部分 ；
   OPEN CURSOR_EMP;
   LOOP
     FETCH CURSOR_EMP
       INTO REC_EMP;
     EXIT WHEN CURSOR_EMP%NOTFOUND;
     PIPE ROW(REC_EMP);
   END LOOP;
   CLOSE CURSOR_EMP;
   RETURN;
 EXCEPTION
   WHEN OTHERS THEN
     DBMS_OUTPUT.PUT_LINE(SQLCODE || SQLERRM);
 END FUN_PAGINATION1;
 END SPILE_PAGE ;
 SELECT * FROM TABLE(SPILE_PAGE.FUN_PAGINATION1(3)) ;