如果设备是新设备,则可能没有任何数据,因此会导致divide by zero。1 )) AS avg_l_day 我尝试过围绕除法子查询使用 浏览17提问于2021-02-10得票数 0 回答已采纳 1回答 无法理解有关更新行锁的PostgreSQL文档 、 当锁子句出现在子选择中时,锁定的行是子查询返回到外部查询的行。这可能比单独检查子查询所显示...
。预定义异常将一些常用SQLCODE绑定名称,所以在Catch是可以使用名字接收(… when ZERO_DIVIDE …)。用户自定异常有两种使用方式: 定义·xxx EXCEPTION;变量,然后直接 mingjie 2022/09/26 5950 PL/SQL --> 异常处理(Exception) sqloracle存储 Exception是一种PL/SQL标识符,当运行的PL/SQL块出现错误或警告,则会...
RAISE_APPLICATION_ERROR(-20001, 'raise a special division by zero exception!'); -- 抛出特定异常码的异常,并为其绑定一个异常信息 EXCEPTION WHEN my_exception THEN -- WHEN zero_divide/division_by_zero THEN RAISE NOTICE '% : %', SQLCODE, SQLERRM; END; 结果显示如下: NOTICE: -20001 : raise ...
例6:ZERO_DIVIDE异常,用数字除以零。 DECLARE v_width INTEGER; v_height INTEGER := 0; v_area INTEGER := 6; BEGIN v_width := v_area / v_height; dbms_output.put_line('v_width = ' || v_width); EXCEPTION WHEN zero_divide THEN dbms_output.put_line('Division by zero'); END; BEGIN...
(numerator/another_label.denominator);--这个会报错,因为引用的是内部的,这个值是0 EXCEPTION WHEN ZERO_DIVIDE THEN DBMS_OUTPUT.PUT_LINE('Divide-by-zero error: can''t divide ' || numerator || ' by ' || denominator); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unexpected error.'); END another...
Then we divide the total of male members by the total of female members to get the ratio. In this case, it returns 200%: Male/Female ratio --- 200 (1 row) Fourth, delete a female member: DELETE FROM members WHERE gender = 2; And execute the query to calculate the male/female...
To set work_mem, take the number of connections, add 32, divide by your astrological sign expressed as a number (Aquarius is 1), convert it to base 7, and then read that number in decimal megabytes. So, I am here to tell you that every formula setting work_mem is wrong. Every. Si...
32-bit operating system, unless you have large file support enabled. By default, we make the limit 1 GB to avoid any possible integer-overflow problems within the OS. A limit smaller than necessary only means we divide a large relation into more chunks than necessary, so it seems best to...
In this case, the inner plan is run in parallelbyall participants. We have the advantages of asharedhash table as described above,andnow we can alsodividethe work of running the inner planandhashing the resulting tuplesbyP participants. Note that ParallelSharedHash is acting as a special kin...
Partition large tables: Use table partitioning to divide large tables into smaller, more manageable pieces. Monitor and kill expensive queries: Use pg_stat_activity to monitor running queries and terminate those consuming excessive resources. How do I tune work_mem in PostgreSQL? chevron_right Tun...