Summary of Predefined PL/SQL Exceptions

An internal exception is raised automatically if your PL/SQL program violates an Oracle rule or exceeds a system-dependent limit. In PL/SQL common Oracle errors are predefined as exceptions. For example, PL/SQL raises the predefined exception NO_DATA_FOUND if a SELECT INTO statement returns no rows. To handle unexpected Oracle errors, you can use the OTHERS handler.

PL/SQL declares predefined exceptions globally in package STANDARD so you do not need to declare them. You can write handlers for predefined exceptions using the predefined names. Table: Predefined PL/SQL Exceptions lists some of the predefined exceptions.

Predefined PL/SQL Exceptions

Exception	Description
`ACCESS_INTO_NULL`	A program attempts to assign values to the attributes of an uninitialized object
`CASE_NOT_FOUND`	None of the choices in the `WHEN` clauses of a `CASE` statement is selected, and there is no `ELSE` clause.
`COLLECTION_IS_NULL`	A program attempts to apply collection methods other than `EXISTS` to an uninitialized nested table or varray, or the program attempts to assign values to the elements of an uninitialized nested table or varray.
`CURSOR_ALREADY_OPEN`	A program attempts to open a cursor that is already open. 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`	A program attempts to store duplicate values in a column that is constrained by a unique index.
`INVALID_CURSOR`	A program attempts a cursor operation that is not allowed, such as closing an unopened cursor.
`INVALID_NUMBER`	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.
`LOGIN_DENIED`	A program attempts to log on to Oracle Database XE with a user name or password that is not valid.
`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. Because this exception is used internally by some SQL functions to signal completion, do not rely on this exception being propagated if you raise it within a function that is called as part of a query.
`NOT_LOGGED_ON`	A program issues a database call without being connected to Oracle Database XE.
`ROWTYPE_MISMATCH`	The host cursor variable and PL/SQL cursor variable involved in an assignment have incompatible return types. When an open host cursor variable is passed to a stored subprogram, the return types of the actual and formal parameters must be compatible.
`SUBSCRIPT_BEYOND_COUNT`	A program references a nested table or varray element using an index number larger than the number of elements in the collection.
`SUBSCRIPT_OUTSIDE_LIMIT`	A program references a nested table or varray element using an index number (-1 for example) that is outside the legal range.
`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 cancels the assignment and raises `VALUE_ERROR`. In procedural statements, `VALUE_ERROR` is raised if the conversion of a character string into a number fails. (In SQL statements, `INVALID_NUMBER` is raised.)
`ZERO_DIVIDE`	A program attempts to divide a number by zero.