PL/SQL、DBMS_SQL无法显示数据

Question

我是 DBMS_SQL 的新人。我试图从光标中获取第一行，但没有显示任何内容。我做错了什么？这是一个代码：

CREATE OR REPLACE PROCEDURE TEST_SQL 
IS 
     id_var             NUMBER; 
     name_var           VARCHAR2(30); 
     sal_var      Number; 
     source_cursor      INTEGER; 
     countp             INTEGER; 
  BEGIN 


     source_cursor := dbms_sql.open_cursor; 
     DBMS_SQL.PARSE(source_cursor, 
         'SELECT employee_id, first_name, salary FROM employees where department_id = 50', 
          DBMS_SQL.NATIVE); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 1, id_var); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 2, name_var, 30); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 3, sal_var); 
     countp := DBMS_SQL.EXECUTE(source_cursor); 


  DBMS_SQL.COLUMN_VALUE(source_cursor, 1, id_var); 
         DBMS_SQL.COLUMN_VALUE(source_cursor, 2, name_var); 
         DBMS_SQL.COLUMN_VALUE(source_cursor, 3, sal_var); 

 dbms_output.put_line('id_var: '||id_var ||', name_var: '||name_var ||', sal_var: '|| sal_var);


  END; 
/

输出为：

PROCEDURE TEST_SQL compiled
anonymous block completed
id_var: , name_var: , sal_var:

编辑：学校错误 - 忘记了 Fetch_rows -.- 一切正常！

Answer 1

你不是fetching任何数据；你需要做的：

DBMS_SQL.FETCH_ROWS(source_cursor);

所以这有效：

CREATE OR REPLACE PROCEDURE TEST_SQL 
IS 
     id_var             NUMBER; 
     name_var           VARCHAR2(30); 
     sal_var      Number; 
     source_cursor      INTEGER; 
     countp             INTEGER; 
  BEGIN 

     source_cursor := dbms_sql.open_cursor; 
     DBMS_SQL.PARSE(source_cursor, 
         'SELECT employee_id, first_name, salary FROM employees where department_id = 50', 
          DBMS_SQL.NATIVE); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 1, id_var); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 2, name_var, 30); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 3, sal_var); 
     countp := DBMS_SQL.EXECUTE(source_cursor); 

     countp := DBMS_SQL.FETCH_ROWS(source_cursor);

     DBMS_SQL.COLUMN_VALUE(source_cursor, 1, id_var); 
     DBMS_SQL.COLUMN_VALUE(source_cursor, 2, name_var); 
     DBMS_SQL.COLUMN_VALUE(source_cursor, 3, sal_var); 

     dbms_output.put_line('id_var: '||id_var ||', name_var: '||name_var ||', sal_var: '|| sal_var);

  END; 
/

set serveroutput on
exec test_sql;

PL/SQL procedure successfully completed.

id_var: 120, name_var: Matthew, sal_var: 8000

或者正如 Tony Andrews 指出的那样，将这两个步骤与 EXECUTE_AND_FETCH 结合起来。

当然，您可能希望在循环中进行提取，因为这只会提取并显示查询返回的第一行。

PL/SQL、DBMS_SQL无法显示数据

PL/SQL, DBMS_SQL can not display data

oracle

plsql

dynamic-sql