示例3:布尔表达式中带有变量的多重IF语句(Example 3: Multiple IF Statement with a variable in a Boolean expression) We can specify multiple SQL IF Statements and execute the statement accordingly. Look at the following example 我们可以指定多个SQL IF语句并相应地执行该语句。 看下面的例子 If a studen...
It executes the ELSE statement and prints the message for it. In this case, we have two SQL IF statements. The second IF statement evaluates to false, therefore, it executes corresponding ELSE statement We need to be careful in specifying conditions in multiple SQL IF statement. We might get...
报错:Update row with Key (id)=(xxxx) multiple times或者duplicate key value violates unique constraint 问题原因:违反唯一性约束,执行UPDATE、INSERT ON CONFLICT或INSERT操作时,主键存在重复数据。 解决方法: 若INSERT语法报错:可以改为INSERT INTO xx ON CONFLICT的语法,实现主键去重,详情请参见INSERT ON CONFLIC...
sql_statement | statement_block: A single or multiple statements that need to be executed. To include multiple statements, enclosed them between BEGIN and END keywords. The ELSE block is optional. If the Boolean expression with the IF statement returns FALSE, then the control is passed to the...
If integer is not a multiple of the database block size, Oracle rounds up (in bytes) to the next multiple. For example, if the database block size is 2048 and integer is 2050, Oracle allocates 4096 bytes (2 blocks). The maximum value is 32768 (32K), which is the largest Oracle ...
SQL is not a procedural language. Using one piece of SQL to do many different things usually results in a less-than-optimal result for each task. If you want SQL to accomplish different things, then write various statements, rather than writing one statement to do different things depending ...
You canthenenter multiple operatingsystemcommands. HO[ST] [command]SQL>host pwd/home/oracle describe 可以查看对象的结构 descobject_name describe不仅可以查询表、视图的结构,而且还可以查询过程、函数和程序包等PL/SQL对象的规范 spool spool命令可以把查询的结果输出到指定的文件中,可以保存查询结果并方便打印。
The special attributesxsi:nilandxsi:typecan't be queried or modified by data manipulation language statements. This means that/e/@xsi:nilfails while/e/@*ignores thexsi:nilandxsi:typeattributes. However,/ereturns thexsi:nilandxsi:typeattributes for consistency withSELECT ...
or sinks.Can be used multiple times.-l,--library<JARdirectory>AJARfile directorywithwhich everynewsessionis initialized.The files might contain user-defined classes neededforthe executionofstatements suchasfunctions,table sources,or sinks.Can be used multiple times.-p,--port<service port>The port...
However, the query returns incorrect results when there are multiple rows per grouping. PIVOT isn't allowed in a recursive common table expression (CTE) query. An error is returned. The RC4 algorithm is only supported for backward compatibility. New material can only be encrypted using RC4 or ...