神之一招

摘要： An Exception is an identifier in PL/SQL that is raised during execution.How is it raised ?- An Oracle error occurs. ( 自动 )- You raise it explicitly. ( RAISE )How do you handle it ?- Trap it with a handler.- Propagate it to the calling environment. ( 外层处理 )Exception TypesImplicitly : Predefined Oracl 阅读全文

摘要： Every PL/SQL construct is composed of one or more blocks . These blocks can be entirely separate or nested within one another .Subprogram :Is a named PL/SQL block that can accept parameters and be invoked from a calling environmentIs of two types :A procedure that performs an actionA function taht c 阅读全文

摘要： - A function is a named PL/SQL block that returns a value.- A function can be stored in the database as a schema object for repeated execution.- A function is called as part of an expression.A function is named PL/SQL block that can accept parameters and be invoked. Generally speaking, you use a fun 阅读全文