In this example, if the deptno column has a 10 in it, the SQL query will return the value accounting rather than the number 10. If the deptno is not 10, 20, 30, or 40, then the CASE statement will fall through to the ELSE clause, which will return unassigned. Note that with a s...
PLSQL 简单case语句 1 简单的case语句会给出一个表达式，并将可能发生的结果与其做比较，如果匹配成功则执行对应的语句 2 语法：[ <<lable_name>> ]CASE case_operandWHEN when_operand1 THEN statement1;[WHEN when_operand2 THENstatement1;] ...[ELSEstatementN]END CASE [ lable_name ];3 说明：<<labl...
搜索式CASE语句有个能够产生boolean(true,false,null)的搜索条件,当特定搜索条件计算结果为TRUE时,会执行与该条件相关的语句组合。搜索式CASE语句的语法如下所示: CASE WHEN SEARCH CONDIDTION 1 THEN STATEMENT 1; WHEN SEARCH CONDIDTION2 THEN STATEMENT 2; ... WHEN SEARCH CONDIDTIONN THEN STATEMENT N; EL...
Fields inherited from interface oracle.javatools.db.sql.SQLFragment CONNECTBY, FROM, GROUPBY, HAVING, NOCYCLE, ORDERBY, SELECT, STARTWITH, TYPE, WHEREFields inherited from interface oracle.javatools.db.DBObject COMMENTConstructor Summary CaseStatement.WhenThen() CaseStatement.WhenThen(SQLFragment ...
Oracle 学习之SQL(一) Retrieving Data Using the SQL SELECT statement,SELECT能干什么?Projection:查询表中指定列。Selection:查询表中指定行。Join:表与表之间做连接,要查看的数据放在多张表中,并且表与表之间的数据有关系。SELECT语句的基本语法:SELECT关键字后
After each stage of execution, the cursor retains enough information about the SQL statement to re-execute the statement without starting over, as long as no other SQL statement has been associated with that cursor. This is illustrated in Figure 7-1. Notice that the statement can be re-...
在看《收获,不止SQL优化》一书,并根据书中例子进行实践,整理成笔记 1.1 索引分类 Oracle索引分为BTree索引、位图索引、反向索引、函数索引、全文索引等等。 1.2 索引数据结构 Oracle索引中最常用的是BTree索引,所以就以BTree索引为例,讲一下BTree索引,BTree索引数据结构是一种二叉树的结构,索引由根块(Root)、茎块...
OracleCASEexpression allows you to addif-elselogic to SQL statements without having to call aprocedure. TheCASEexpression evaluates a list of conditions and returns one of the multiple possible results. You can use aCASEexpression in any statement or clause that accepts a valid expression. For ex...
This SQL tutorial demonstrates how to create a basic Oracle SELECT statement, and provides explanations, examples and exercises.
oracle注入中可以通过页面响应的状态,这里指的是响应时间,通过这种方式判断SQL是否被执行的方式,便是时间盲注。 oracle的时间盲注通常使用DBMS_PIPE.RECEIVE_MESSAGE(),而另外一种便是decode()与高耗时SQL操作的组合,当然也可以是case,if 等方式与高耗时操作的组合,这里的高耗时操作指的是,例如:(select count(*) ...