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  • 对PLSQL的cursor 的rowcount 的理解

    开始

    rowcount 并不是定义或open了cursor,就是固定的值,它随着每次fetch而累计:

    --INDEX BY Table
    SET SERVEROUTPUT ON;
    
    DECLARE
      v_empno emp.empno%TYPE;
      v_ename emp.ename%TYPE;
      
      CURSOR emp_cursor IS
      SELECT empno,ename from emp where empno<>1000;
      
    BEGIN
    
    LOOP
    
      IF NOT emp_cursor%ISOPEN  THEN
         OPEN emp_cursor;
      END IF; 
      
      FETCH emp_cursor INTO  v_empno,v_ename; 
      EXIT WHEN emp_cursor%NOTFOUND;
       
      dbms_output.put_line(
    'rowcount is:'|| emp_cursor%ROWCOUNT || '-- empno is:' || v_empno || '-- emp name is:' || v_ename); END LOOP; END; /

    运行结果:

    anonymous block completed
    rowcount is:1-- empno is:7369-- emp name is:SMITH
    rowcount is:2-- empno is:7499-- emp name is:ALLEN
    rowcount is:3-- empno is:7521-- emp name is:WARD
    rowcount is:4-- empno is:7566-- emp name is:JONES
    rowcount is:5-- empno is:7654-- emp name is:MARTIN
    rowcount is:6-- empno is:7698-- emp name is:BLAKE
    rowcount is:7-- empno is:7782-- emp name is:CLARK
    rowcount is:8-- empno is:7788-- emp name is:SCOTT
    rowcount is:9-- empno is:7839-- emp name is:KING
    rowcount is:10-- empno is:7844-- emp name is:TURNER
    rowcount is:11-- empno is:7876-- emp name is:ADAMS
    rowcount is:12-- empno is:7900-- emp name is:JAMES
    rowcount is:13-- empno is:7902-- emp name is:FORD
    rowcount is:14-- empno is:7934-- emp name is:MILLER

    结束

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  • 原文地址:https://www.cnblogs.com/gaojian/p/2769385.html
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