Oracle基礎：5: sql錯誤資訊的控制和定位
阿新 • • 發佈：2018-11-11
在sqlplus中執行的sql出錯之後應該如何處理和對應，多行sql語句或者儲存過程的資訊如何進行錯誤定位，這篇文章將結合例項進行簡單地說明。
環境準備
使用Oracle的精簡版建立docker方式的demo環境，詳細可參看：
如何進行錯誤定位
場景：
假如有3行insert的sql語句，中間一行出錯之後，後續繼續執行的情況下，如何定位到第二行？
dbms_utility.format_error_backtrace
通過使用dbms_utility.format_error_backtrace可以得到ERROR at line xxx:的資訊，這對我們較為有用，我們接下來進行確認
[email protected]:~$ sqlplus system/[email protected] <<EOF
> SET SERVEROUTPUT ON
> desc student
> delete from student;
> select * from student;
> insert into student values (1001, 'liumiaocn');
> insert into student values (1001, 'liumiao');
> insert into student values (1003, 'michael');
> select * from student;
> commit;
> exec dbms_output.put_line(dbms_utility.format_error_backtrace);
> EOF
SQL*Plus: Release 11.2.0.2.0 Production on Sun Oct 21 13:06:07 2018
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> SQL> Name Null? Type
----------------------------------------- -------- ----------------------------
STUID NOT NULL NUMBER(4)
STUNAME VARCHAR2(50)
SQL>
2 rows deleted.
SQL>
no rows selected
SQL>
1 row created.
SQL> insert into student values (1001, 'liumiao')
*
ERROR at line 1:
ORA-00001: unique constraint (SYSTEM.SYS_C007024) violated
SQL>
1 row created.
SQL>
STUID STUNAME
---------- --------------------------------------------------
1001 liumiaocn
1003 michael
SQL>
Commit complete.
SQL>
PL/SQL procedure successfully completed.
SQL> Disconnected from Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
可以看到，報錯的時候提示了行號，但是行號是1，這是因為這種寫法以一行為單位，自然是如此，如果是單個多行的儲存過程，將會更加清晰。
ERROR at line 1:
ORA-00001: unique constraint (SYSTEM.SYS_C007024) violated
所以我們將這個例子進行改造，三行insert的sql放到檔案之中，然後在使用dbms_utility.format_error_backtrace來進行確認
[email protected]:~$ cat /tmp/sqltest1.sql
desc student
delete from student;
select * from student;
insert into student values (1001, 'liumiaocn');
insert into student values (1001, 'liumiao');
insert into student values (1003, 'michael');
select * from student;
commit;
然後在嘗試一下是否能夠確認行號，會發現仍然不能精確定位：
[email protected]:~$ sqlplus system/[email protected] <<EOF
> SET SERVEROUTPUT ON
> @/tmp/sqltest1.sql
> exec dbms_output.put_line(dbms_utility.format_error_backtrace);
> EOF
SQL*Plus: Release 11.2.0.2.0 Production on Sun Oct 21 13:08:27 2018
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> SQL> Name Null? Type
----------------------------------------- -------- ----------------------------
STUID NOT NULL NUMBER(4)
STUNAME VARCHAR2(50)
2 rows deleted.
no rows selected
1 row created.
insert into student values (1001, 'liumiao')
*
ERROR at line 1:
ORA-00001: unique constraint (SYSTEM.SYS_C007024) violated
1 row created.
STUID STUNAME
---------- --------------------------------------------------
1001 liumiaocn
1003 michael
Commit complete.
SQL>
PL/SQL procedure successfully completed.
SQL> Disconnected from Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
[email protected]:~$
因為dbms_utility.format_error_backtrace更多的場景是在於儲存過程的錯誤定位，接下來我們使用一個簡單的儲存過程例子來進行確認錯誤行號定位, 先看一個正常的儲存過程，把上面的內容稍微修改一下：
[email protected]:~$ cat /tmp/addstudent.sql
create or replace PROCEDURE addstudents
IS
student_count number;
BEGIN
delete from student;
select count(*) into student_count from student;
dbms_output.put('sql set count before :');
dbms_output.put_line(student_count);
insert into student values (1001, 'liumiaocn');
insert into student values (1002, 'liumiao');
insert into student values (1003, 'michael');
select count(*) into student_count from student;
dbms_output.put('sql set count after :');
dbms_output.put_line(student_count);
END;
/
exec addstudents();
[email protected]:~$
結果執行資訊如下
[email protected]2341c0:~$ sqlplus system/liumiao123 <<EOF
set serveroutput on;
@/tmp/addstudent.sql
EOF
SQL*Plus: Release 11.2.0.2.0 Production on Mon Oct 22 04:42:11 2018
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> SQL>
Procedure created.
sql set count before :0
sql set count after :3
PL/SQL procedure successfully completed.
SQL> Disconnected from Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
[email protected]:~$
接下來我們修改一下內容，使得第二行主鍵重複
[email protected]:~$ cat /tmp/addstudent.sql
create or replace PROCEDURE addstudents
IS
student_count number;
BEGIN
delete from student;
select count(*) into student_count from student;
dbms_output.put('sql set count before :');
dbms_output.put_line(student_count);
insert into student values (1001, 'liumiaocn');
insert into student values (1001, 'liumiao');
insert into student values (1003, 'michael');
select count(*) into student_count from student;
dbms_output.put('sql set count after :');
dbms_output.put_line(student_count);
END;
/
exec addstudents();
[email protected]:~$
再次執行，自然會出錯，但是可以看到，正確報出了所在行數，這是procedure的機制提示的資訊
[email protected]:~$ sqlplus system/liumiao123 <<EOF
set serveroutput on;
@/tmp/addstudent.sql
EOF
SQL*Plus: Release 11.2.0.2.0 Production on Mon Oct 22 04:44:25 2018
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> SQL>
Procedure created.
sql set count before :0
BEGIN addstudents(); END;
*
ERROR at line 1:
ORA-00001: unique constraint (SYSTEM.SYS_C007024) violated
ORA-06512: at "SYSTEM.ADDSTUDENTS", line 10
ORA-06512: at line 1
SQL> Disconnected from Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
[email protected]:~$
可以看到，ORA-06512: at “SYSTEM.ADDSTUDENTS”, line 10的資訊就是我們期待的資訊，提示出在這個儲存過程的第10行執行出現問題，而實際可以使用dbms_utility.format_error_backtrace結合exception給出更為清晰地方式，比如：
[email protected]:~$ cat /tmp/addstudent.sql
create or replace PROCEDURE addstudents
IS
student_count number;
BEGIN
delete from student;
select count(*) into student_count from student;
dbms_output.put('sql set count before :');
dbms_output.put_line(student_count);
insert into student values (1001, 'liumiaocn');
insert into student values (1001, 'liumiao');
insert into student values (1003, 'michael');
select count(*) into student_count from student;
dbms_output.put('sql set count after :');
dbms_output.put_line(student_count);
exception
when others then
dbms_output.put('exception happend with line info : ');
dbms_output.put_line(dbms_utility.format_error_backtrace);
END;
/
exec addstudents();
[email protected]:~$
執行結果確認：
[email protected]:~$ sqlplus system/liumiao123 <<EOF
set serveroutput on;
@/tmp/addstudent.sql
EOF
SQL*Plus: Release 11.2.0.2.0 Production on Mon Oct 22 04:49:27 2018
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> SQL>
Procedure created.
sql set count before :0
exception happend with line info : ORA-06512: at "SYSTEM.ADDSTUDENTS", line 10
PL/SQL procedure successfully completed.
SQL> Disconnected from Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
[email protected]:~$
這樣則可以看出能夠比較清晰地進行錯誤的定位了，但是由於功能受限，所以實際使用場景仍然較為有限，但是定位儲存過程的資訊則可以使用dbms_utility.format_error_backtrace等進行確認。
總結
多行sql執行定位可以考慮拆成單行來確認，而儲存過程則可結合format_error_backtrace等進行確認以提供問題出現的所在行號。