oracle中常见异常解释
ORA-00904: invalid column name 无效列名
ORA-00942: table or view does not exist 表或者视图不存在

ORA-01400: cannot insert NULL into () 不能将空值插入

ORA-00936:　缺少表达式

ORA-00933:　SQL 命令未正确结束

ORA-01722:　无效数字：（一般可能是企图将字符串类型的值填入数字型而造成）

ORA-06530: ACCESS_INTO_NULL　
      Your program attempts to assign values to the attributes of an uninitialized (atomically null) object.
企图将值写入未初化对象的属性

ORA-06592: CASE_NOT_FOUND
     None of th choice in the WHEN clauses of a CASE statement is selected, and there is no ELSE clause.
case语句格式有误，没有分支语句

ORA-06531: COLLECTION_IS_NULL
     Your program attempts to apply collection methods othe than EXIST to an uninitialized(atomically null) nested table or varray, or th program attempts to assign values to the elements of an uninitialized nested table or varray.
企图将集合填入未初始化的嵌套表中

ORA-06511: CURSOR_ALREADY_OPEN
     Your program attempts to open an already 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.
企图打开已经打开的指针．指针已经打开，要再次打开必须先关闭．

ORA-00001: DUP_VAL_ON_INDEX
     Your program attempts to store duplicate values in a database column that is constrained by a unique index.
数据库字段存储重复，主键唯一值冲突

ORA-01001: INVALID_CURSOR　无效指针
    Your program attempts an illegal cursor operation such as closing an unopened cursor.
非法指针操作，例如关闭未打开的指针

ORA-01722: INVALID_NUMBER　无效数字
     In a SQL statement, the conversion of a character string into a number fails because the string 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.
在sql语句中，字符数字类型转换错误，无法将字符串转化成有效数字．此错误也可能因为在limit从句表达式中fetch语句无法对应指定数字

ORA-01017: LOGIN_DENIED　拒绝访问
     Your program attempts to log on to Oracle with an invalid username and/or password.
企图用无效的用户名或密码登录oracle

ORA-01403: NO_DATA_FOUND 无数据发现
     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.

ORA-01012: NOT_LOGGED_ON   未登录
     Your program issues a database call without being connected to Oracle.
程序发送数据库命令，但未与oracle建立连接

ORA-06501: PROGRAM_ERROR 程序错误
     PL/SQL has an internal problem.
pl/sql系统问题

ORA-06504: ROWTYPE_MISMATCH 行类型不匹配
    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.

ORA-30625: 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.

ORA-06500: STORAGE_ERROR 存储错误
     PL/SQL runs out of memory or memory has been corrupted.
PL/SQL运行内存溢出或内存冲突
     
ORA-06533: SUBSCRIPT_BEYOND_COUNT   子句超出数量
   &