ORACLE异常

异常

1.简介
  异常处理块中包含了与异常相关的错误发生以及当错误发生时要进行执行和处理的代码。异常部分的语法一般如下：

<!---->BEGIN
  EXCEPTION
  WHEN Excep_Name1 THEN
    Statements1;
  WHEN Excep_Name2 THEN
    Statements2;
  WHEN OTHERS THEN
    Statements3;
END;

2.预定义异常
简单列一下常用的吧：

异常名	异常标题	异常号
ACCESS_INTO_NULL	ORA-06530	-6530
CASE_NOT_FOUND	ORA-06592	-6592
COLLECTION_IS_NULL	ORA-06531	-6531
CURSOR_ALREADY_OPEN	ORA-06511	-6511
DUP_VAL_ON_INDEX	ORA-00001	-1
INVALID_CURSOR	ORA-01001	-1001
INVALID_NUMBER	ORA-01722	-1722
LOGIN_DENIED	ORA-01017	-1017
NO_DATA_FOUND	ORA-01403	-1403
NOT_LOGGED_ON	ORA-01012	-1012
PROGRAM_ERROR	ORA-06501	-6501
ROWTYPE_MISMATCH	ORA-06504	-6504
SELF_IS_NULL	ORA-30625	-30625
STORAGE_ERROR	ORA-06500	-6500
SUBSCRIPT_BEYOND_COUNT	ORA-06533	-6533
SUBSCRIPT_OUTSIDE_LIMIT	ORA-06532	-6532
SYS_INVALID_ROWID	ORA-01410	-1410
TIMEOUT_ON_RESOURCE	ORA-00051	-51
TOO_MANY_ROWS	ORA-01422	-1422
VALUE_ERROR	ORA-06502	-6502
ZERO_DIVIDE	ORA-01476	-1476

以上异常说明：

异常名	说明
ACCESS_INTO_NULL	Your program attempts to assign values to   the attributes of an  uninitialized (atomically null) object.
CASE_NOT_FOUND	one of the choices in the WHEN clauses of a  ASE  tatement is selected, and there is no  ELSE clause.
COLLECTION_IS_NULL	Your program attempts to apply collection methods other than EXISTS to an uninitialized (atomically null) nested table or varray, or the program attempts to assign values to the elements of an uninitialized nested table or varray.
CURSOR_ALREADY_OPEN	Your program attempts to open an alrea*** open cursor. A cursor must be closed before it can be reopened. A cursor FOR loop automatically opens the cursor to which it refers. So, your program cannot open that cursor inside the loop.
DUP_VAL_ON_INDEX	Your program attempts to store duplicate values in a database column that is constrained by a unique index.
INVALID_CURSOR	Your program attempts an illegal cursor operation such as closing an unopened cursor.
INVALID_NUMBER	In a SQL statement, the conversion of a character st***  into a number fails because the st***  does not represent a valid number. (In procedural statements, VALUE_ERROR is raised.) This exception is also raised when the LIMIT-clause expression in a bulk FETCH statement does not evaluate to a positive number.
LOGIN_DENIED	Your program attempts to log on to Oracle with an invalid username and/or password.
NO_DATA_FOUND	A SELECT INTO statement returns no rows, or your program references a deleted element in a nested table or an uninitialized element in an index-by table. SQL aggregate functions such as AVG and SUM always return a value or a null. So, a SELECT INTO statement that calls an aggregate function never raises NO_DATA_FOUND. The FETCH statement is expected to return no rows eventually, so when that happens, no exception is raised.
NOT_LOGGED_ON	Your program issues a database call without being connected to Oracle.
PROGRAM_ERROR	PL/SQL has an internal problem.
ROWTYPE_MISMATCH	The host cursor variable and PL/SQL cursor variable involved in an assignment have incompatible return types. For example, when an open host cursor variable is passed to a stored subprogram, the return types of the actual and formal parameters must be compatible.
SELF_IS_NULL	Your program attempts to call a MEMBER method on a null instance. That is, the built-in parameter SELF (which is always the first parameter passed to a MEMBER method) is null.
STORAGE_ERROR	PL/SQL runs out of memory or memory has been corrupted.
SUBSCRIPT_BEYOND_COUNT	Your program references a nested table or varray element using an index number larger than the number of elements in the collection.
SUBSCRIPT_OUTSIDE_LIMIT	Your program references a nested table or varray element using an index number (-1 for example) that is outside the legal range.
SYS_INVALID_ROWID	The conversion of a character st***  into a universal rowid fails because the character st***  does not represent a valid rowid.
TIMEOUT_ON_RESOURCE	A time-out occurs while Oracle is waiting for a resource.
TOO_MANY_ROWS	A SELECT INTO statement returns more than one row.
VALUE_ERROR	An arithmetic, conversion, truncation, or size-constraint error occurs. For example, when your program selects a column value into a character variable, if the value is longer than the declared length of the variable, PL/SQL aborts the assignment and raises VALUE_ERROR. In procedural statements, VALUE_ERROR is raised if the conversion of a character st***  into a number fails. (In SQL statements, INVALID_NUMBER is raised.)
ZERO_DIVIDE	Your program attempts to divide a number by zero.

3.自定义异常
  异常不一定必须是Oracle返回的系统错误，用户可以在自己的应用程序中创建可触发及可处理的自定义异常，调用异常处理需要使用RAISE语句。
  异常情态的传播指的是当在程序块的声明、执行、异常部分分别出现异常情态时，或在本块中没有相应的异常处理器时会将这个异常情态传播到哪里，会去激发那个块中的处理器。传播规则是这样的：当一个异常情态是在块的执行部分引发的(最常见的)，PL/SQL使用下面的规则确定激活哪个异常处理器。
  ① 若当前块对该异常情态设置了处理器，则执行它并成功完成该块的执行，然后控制转给包含块。
  ② 若当前块没有该处理器，则通过在包含块中引发它来传播异常情态。然后对包含块执行PL/SQL的异常操作。另外，无论是在声明部分引发了一个异常情态，还是在异常处理部分引发，则该异常情态将立即传播给包含块。在包含块引用上述规则进行异常情态的处理，即使在当前块设置了OTHERS处理器也不会被执行。