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PL/SQL异常处理方法

时间:2021-07-01 10:21:17 帮助过:20人阅读

DUP_VAL_ON_INDEX  ORA-00001  You tried to execute an INSERT or UPDATE statement that has created a duplicate value in a field restricted by a unique index. TIMEOUT_ON_RESOURCE  ORA-00051  You were waiting for a resource and you timed out. TRANSACTION_BACKED_OUT  ORA-00061  The remote portion of a transaction has rolled back. INVALID_CURSOR  ORA-01001  You tried to reference a cursor that does not yet exist. This may have happened because you‘ve executed a FETCH cursor or CLOSE cursor before OPENing the cursor. NOT_LOGGED_ON  ORA-01012  You tried to execute a call to Oracle before logging in. LOGIN_DENIED  ORA-01017  You tried to log into Oracle with an invalid username/password combination. NO_DATA_FOUND  ORA-01403  You tried one of the following: You executed a SELECT INTO statement and no rows were returned. You referenced an uninitialized row in a table. You read past the end of file with the UTL_FILE package. TOO_MANY_ROWS  ORA-01422  You tried to execute a SELECT INTO statement and more than one row was returned. ZERO_DIVIDE  ORA-01476  You tried to divide a number by zero. INVALID_NUMBER  ORA-01722  You tried to execute an SQL statement that tried to convert a string to a number, but it was unsuccessful. STORAGE_ERROR  ORA-06500  You ran out of memory or memory was corrupted. PROGRAM_ERROR  ORA-06501  This is a generic "Contact Oracle support" message because an internal problem was encountered. VALUE_ERROR  ORA-06502  You tried to perform an operation and there was a error on a conversion, truncation, or invalid constraining of numeric or character data. CURSOR_ALREADY_OPEN  ORA-06511  You tried to open a cursor that is already open. 以上的例子中有关于命名的异常的使用方法。这里不再说了。 BEGIN    Execution section EXCEPTION  WHEN NO_DATA_FOUND THEN   dbms_output.put_line (‘A SELECT...INTO did not return any row.‘);   END;    b:未命名系统异常: 这些系统异常没有名字,这些异常不经常出现,这些异常有错误代码和关联信息。 有两种方式处理未命名的异常:         方法一: 使用WHEN OTHERS 异常处理         方法二:给一个异常 关联异常代码和名称 ,然后像命名异常一样使用它。 方法一异常没有目标性,下面说明方法二: 使用Pragma 调用 EXCEPTION_INIT关联一个预定义的oracle错误号到程序定义的异常 下面是个demo: DECLARE     exception_name EXCEPTION;     PRAGMA     EXCEPTION_INIT (exception_name, Err_code);  BEGIN  Execution section EXCEPTION   WHEN exception_name THEN      handle the exception END; 先声明异常名称,然后调用EXCEPTION_INIT函数绑定错误号码和异常名称, 绑定后这个异常名称就可以像命名式异常那样用了。 例如: [sql]  SQL> DECLARE     2         e_insert_excep  EXCEPTION;  --定义异常名称     3         PRAGMA EXCEPTION_INIT(e_insert_excep,-01400);   -- 关联异常名称和异   常号     4         BEGIN     5         INSERT INTO departments (department_id,department_name) VALUES(280,N   ULL);     6         EXCEPTION     7          WHEN  e_insert_excep THEN     8            DBMS_OUTPUT.PUT_LINE(‘INSERT OPERATION FAILED‘);     9            DBMS_OUTPUT.PUT_LINE(SQLERRM);    10         END;    11  /   INSERT OPERATION FAILED   ORA-01400: 无法将 NULL 插入 ("HR"."DEPARTMENTS"."DEPARTMENT_NAME")      PL/SQL 过程已成功完成。     首先定义一个 e_insert_excep异常名称, 然后调用 EXCEPTION_INIT函数绑定这个异常名称,最后出现异常输出错误信息。 SQLERRM的信息如下: ORA-01400: 无法将 NULL 插入 ("HR"."DEPARTMENTS"."DEPARTMENT_NAME")     需要关联 数字和自定义的错误名称; 两个变量: SQLCODE  错误代码             SQLERRM  错误内容    当抛出异常的时候,这两个变量会被自动填充,可以获取这两个的值来判断    错误:            3:用户自定义异常: 先看三个例子再解释: ex1: [sql]  SQL>  DECLARE     2       v_deptno NUMBER := 500;     3       v_name  VARCHAR2(20)  :=‘Testing‘;     4       e_invalid_department EXCEPTION;     5    BEGIN     6       UPDATE departments SET department_name = v_name     7       WHERE  department_id = v_deptno;     8     9       IF SQL%NOTFOUND THEN    10          RAISE  e_invalid_department;    11       END IF;    12       COMMIT;    13     EXCEPTION    14       WHEN e_invalid_department THEN    15        DBMS_OUTPUT.PUT_LINE(‘No such department id‘);    16    END;    17  /   No such department id      PL/SQL 过程已成功完成。     关于RAISE_APPLICATION_ERROR  过程; 语法: raise_application_error(error_number,message[,{TRUE|FALSE}]); 可以通过这个过程定义一个自己的异常号和 异常信息 注意: error_number是介于: -20000..-20999的数字,message是一个 字符串最大长度为2k [sql]  SQL> DECLARE     2      v_deptno NUMBER := 500;     3      v_name VARCHAR2(20) := ‘Testing‘;     4      e_invalid_department EXCEPTION;  --定义一个异常     5      PRAGMA  EXCEPTION_INIT(e_invalid_department,-20188);    --把异常和异常   号绑定;     6  BEGIN     7      UPDATE  departments     8      SET  department_name =v_name     9      WHERE department_id = v_deptno;    10    11      IF SQL%NOTFOUND THEN    12    13         RAISE_APPLICATION_ERROR(-20188,‘I write my error message here !‘);       14     END IF;    15     COMMIT;    16   EXCEPTION    17          WHEN  e_invalid_department THEN    18               DBMS_OUTPUT.PUT_LINE(SQLCODE || ‘--->‘ || SQLERRM);    19  END;    20    21  /   -20188--->ORA-20188: I write my error message here !      PL/SQL 过程已成功完成。   说明:RAISE_APPLICATION_ERROR ( ) RAISE_APPLICATION_ERROR是一个内建的存储过程,这个存储过程可以显示用户 自定义的错误信息和错误号 ,这些错误号是Oracle开放出来供开发者用的, 范围为:-20000 and -20999 当使用RAISE_APPLICATION_ERROR的时候,所以以前的事务不提交,自动回滚。 语法格式如下: RAISE_APPLICATION_ERROR (error_number, error_message);  使用RAISE_APPLICATION_ERROR步骤如下:   1:首先在Declaration区域自定义一个exception, 2:在特定的逻辑规则下出现 Raise 用户自定义的exception 3:最后 catch 这个异常,在捕获后使用RAISE_APPLICATION_ERROR这个过程链接 自定义的错误号和错误信息。   重点: 关于异常的传播机制: 比较以下三个例子就会明白异常的传播机制: ex1: [sql]  CREATE OR REPLACE PROCEDURE add_more_departments(p_name1 VARCHAR2, p_mgr1 NUMBER, p_loc1 NUMBER,p_name2 VARCHAR2, p_mgr2 NUMBER, p_loc2 NUMBER) IS   BEGIN     INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name1,p_mgr1,p_loc1);     DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name1);        INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name2,p_mgr2,p_loc2);    DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name2);      EXCEPTION          WHEN OTHERS THEN            DBMS_OUTPUT.PUT_LINE(‘Err: adding dept:‘);   END;   /              CREATE OR REPLACE PROCEDURE create_more_departments   IS   BEGIN     add_more_departments(‘Media‘,100,1800,‘Editing‘,99,1800);   END;   /      BEGIN   create_more_departments;   END;      这个例子中 99这条记录在表中本来就有,现在再次进行插入,会冲突报错 执行结果:以上两个insert 只有第一个插入进去了,第二个插入失败。 执行结果如下: SQL> / Add Dept: Media Err: adding dept: PL/SQL 过程已成功完成。     DEPARTMENT_ID DEPARTMENT_NAME ------------- ------------------------------           230 IT Helpdesk           240 Government Sales           250 Retail Sales           260 Recruiting           270 Payroll           340 Media     已选择28行。 只有第一条被插入 ex2: 在做第二个例子前先把上次的实验结果删除掉: delete from departments where department_id >270; select department_id,department_name from departments order by 1;   [sql]  CREATE OR REPLACE PROCEDURE add_more_departments(p_name1 VARCHAR2, p_mgr1 NUMBER, p_loc1 NUMBER,p_name2 VARCHAR2, p_mgr2 NUMBER, p_loc2 NUMBER) IS   BEGIN     INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name1,p_mgr1,p_loc1);     DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name1);        INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name2,p_mgr2,p_loc2);    DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name2);      END;   /              CREATE OR REPLACE PROCEDURE create_more_departments   IS   BEGIN     add_more_departments(‘Media‘,100,1800,‘Editing‘,99,1800);   END;   /       BEGIN   create_more_departments;   END;      执行结果如下: SQL> BEGIN   2  create_more_departments;   3  END;   4  / Add Dept: Media BEGIN * 第 1 行出现错误: ORA-02291: 违反完整约束条件 (HR.DEPT_MGR_FK) - 未找到父项关键字 ORA-06512: 在 "HR.ADD_MORE_DEPARTMENTS", line 6 ORA-06512: 在 "HR.CREATE_MORE_DEPARTMENTS", line 4 ORA-06512: 在 line 2   查询结果:     DEPARTMENT_ID DEPARTMENT_NAME ------------- ------------------------------           230 IT Helpdesk           240 Government Sales           250 Retail Sales           260 Recruiting           270 Payroll 这次没有异常处理,把异常处理去掉了。 这次的执行结果: 两条记录一条记录也没有插入进去。  ex3: delete from departments where department_id >270; select department_id,department_name from departments order by 1;   [sql]  CREATE OR REPLACE PROCEDURE add_more_departments(p_name1 VARCHAR2, p_mgr1 NUMBER, p_loc1 NUMBER,p_name2 VARCHAR2, p_mgr2 NUMBER, p_loc2 NUMBER) IS   BEGIN     INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name1,p_mgr1,p_loc1);     DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name1);        INSERT INTO departments(department_id,department_name,manager_id,location_id)VALUES(departments_seq.NEXTVAL,p_name2,p_mgr2,p_loc2);    DBMS_OUTPUT.PUT_LINE(‘Add Dept: ‘ || p_name2);      END;   /              CREATE OR REPLACE PROCEDURE create_more_departments   IS   BEGIN     add_more_departments(‘Media‘,100,1800,‘Editing‘,99,1800);   EXCEPTION          WHEN OTHERS THEN            DBMS_OUTPUT.PUT_LINE(‘Errors have happend‘);     END;   /    BEGIN   create_more_departments;   END;      执行结果: SQL> BEGIN   2  create_more_departments;   3  END;   4  / Add Dept: Media Errors have happend   PL/SQL 过程已成功完成。 查询结果: DEPARTMENT_ID DEPARTMENT_NAME ------------- ------------------------------           230 IT Helpdesk           240 Government Sales           250 Retail Sales           260 Recruiting           270 Payroll           400 Media   这次把异常处理放在了最外面:调用的最外面: 执行结果如下: 执行成功的第一条语句被成功插入,第二条被捕获。

PL/SQL异常处理方法

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