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Oracle® Database PL/SQL Language Reference
11g Release 2 (11.2)

Part Number E17126-03
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Explicit Cursor

An explicit cursor is a named pointer to a private SQL area that stores information for processing a specific query or DML statement—typically, one that returns or affects multiple rows. You can use an explicit cursor to retrieve the rows of a result set one at a time.

Before using an explicit cursor, you must declare and define it. You can either declare it first (with cursor_declaration) and then define it later in the same block, subprogram, or package (with cursor_definition) or declare and define it at the same time (with cursor_definition).

An explicit cursor declaration and definition are also called a cursor specification and cursor body, respectively.

Note:

An explicit cursor declared in a package specification is affected by the AUTHID clause of the package. For more information, see "CREATE PACKAGE Statement".

Topics:

Syntax

cursor_declaration ::=

cursor_spec
Description of the illustration cursor_declaration.gif

cursor_definition ::=

cursor_declaration
Description of the illustration cursor_definition.gif

See "rowtype ::=".

cursor_parameter_declaration ::=

cursor_parameter_declaration
Description of the illustration cursor_param_declaration.gif

See:

rowtype ::=

rowtype
Description of the illustration rowtype_attribute.gif

Semantics

cursor_declaration

cursor_name

The name of the explicit cursor that you are declaring now and will define later in the same block, subprogram, or package. This name can be any identifier except the reserved word SQL. Oracle recommends against giving a cursor the same name as a database table.

Explicit cursor names follow the same scoping rules as variables (see "Scope and Visibility of Identifiers").

rowtype

The data type of the row that the cursor returns.

cursor_definition

Either defines an explicit cursor that was declared earlier or both declares and defines an explicit cursor.

cursor_name

Either the name of the explicit cursor that you previously declared and are now defining or the name of the explicit cursor that you are both declaring and defining. This name can be any identifier except the reserved word SQL. Oracle recommends against giving a cursor the same name as a database table.

rowtype

The data type of the row that the cursor returns. The columns of this row must match the columns of the row that select_statement returns.

select_statement

A SQL SELECT statement (not a PL/SQL SELECT INTO statement). If the cursor has formal parameters, each parameter must appear in select_statement. The select_statement can also reference other PL/SQL variables in its scope.

See:

Oracle Database SQL Language Reference for SELECT statement syntax

cursor_parameter_declaration

parameter_name

The name of the formal cursor parameter that you are declaring. This name can appear anywhere in select_statement that a constant can appear.

IN

Whether or not you specify IN, a formal cursor parameter has the characteristics of an IN subprogram parameter, which are summarized in Table 8-1. When the cursor opens, the value of the formal parameter is that of either its actual parameter or default value.

datatype

The data type of the parameter.

Restriction on datatype This datatype cannot have constraints (for example, NOT NULL, or precision and scale for a number, or length for a string).

expression

Specifies the default value for the formal cursor parameter. The data types of expression and the formal cursor parameter must be compatible.

If an OPEN statement does not specify an actual parameter for the formal cursor parameter, then the statement evaluates expression and assigns its value to the formal cursor parameter.

If an OPEN statement does specify an actual parameter for the formal cursor parameter, then the statement assigns the value of the actual parameter to the formal cursor parameter and does not evaluate expression.

rowtype

db_table_name

The name of a database table or view that is accessible when the cursor declaration is elaborated.

cursor_name

The name of another explicit cursor (not the name of the cursor that you are declaring or defining).

cursor_variable_name

The name of a cursor variable.

record_name

The name of a record.

record_type_name

The name of a type that was defined with the data type specifier RECORD.

Examples

Related Topics

In this chapter:

In other chapters: