在ORDER BY子句中使用CASE表达式将所有组合列入白名单。当条件不匹配时，CASE表达式将返回NULL，并且所有行...
CASE expression syntax is similar to an IF-THEN-ELSE statement. Oracle checks each condition starting from the first condition (left to right). When a particular condition is satisfied (WHEN part) the expression returns the tagged value (THEN part). If none of the conditions are matched, the...
只可以用在pl/sql中,不能用在SQL中,结束标志是END CASE!Case Statement 相当于一组IF…THEN…ELSE…END IF语句,不需要返回值,只是在条件匹配的时候执行某种操作而已,所以在每个WHEN…THEN之后需要有一个分号,表示一条执行语句! CASE {variable or expression} WHEN {value} THEN {one or more operations};[WHE...
The conditions that must all be the same datatype. The conditions are evaluated in the order listed. Once aconditionis found to be true, the CASE statement will return the result and not evaluate the conditions any further. result_1, result_2, ... result_n Results that must all be the...
create view 视图名 as select statement 13、删除视图 drop view viewname Oracle操作数据 1、数据查询 select <列名> from <表名> [where <查询条件表达试>] [order by <排序的列名>[asc或desc]] 2、插入数据 语法一: insert into 表名 values(所有列的值); ...
utl_inaddr.get_host_name()函数报错注入 utl_inaddr.get_host_address 本意是获取ip 地址,但是如果传递参数无法得到解析就会返回一个oracle 错误并显示传递的参数。 我们传递的是一个sql 语句所以返回的就是语句执行的结果。oracle 在启动之后,把一些系统变量都放置到一些特定的视图当中,可以利用这些视图获得想要的...
Operation of this equipment in a residential area is likely to cause harmful interference, in which case the user will be required to correct the interference at his own expense. Modifications: Any modifications made to this device that are not approved by Oracle may void the authority granted ...
case when distinct union 不过好在这些在java/js中处理都比较方便。 如果有很复杂的SQL,那最大的可能就是设计上有问题,应该采用读写分离解决。 sharding-jdbc对SQL的限制完整可以参考http://shardingsphere.io/document/current/cn/features/sharding/usage-standard/sql/ ...
Notice it doesn't say the statements in the "true" WHEN clause. So even if the when statement is false, the nextval will fire: select case when 1=0 then 'next ' || seq_id.nextval when 1=1 then 'curr ' || seq_id.currval ...
Construct the SQL query dynamically by using the IN clause and passing the list or array of values. Here's a sample code snippet: 代码语言:txt 复制 // Assuming you have already established a database connection using JDBC // Step 1: Retrieve the result set Statement statement = connection....