Can I use variable in cursor Oracle?
To create a cursor variable, either declare a variable of the predefined type SYS_REFCURSOR or define a REF CURSOR type and then declare a variable of that type. You cannot use a cursor variable in a cursor FOR LOOP statement.
What is a substitution variable in Oracle?
A substitution variable is a user variable name preceded by one or two ampersands (&). When SQL*Plus encounters a substitution variable in a command, SQL*Plus executes the command as though it contained the value of the substitution variable, rather than the variable itself.
Can we pass parameters to cursor in Oracle?
Each time you open the cursor, you can pass different arguments to the cursor, which results in different result sets. In the cursor query, each parameter in the parameter list can be used anywhere which a constant is used. The cursor parameters cannot be referenced outside of the cursor query.
Which statements is are used to control a cursor variable?
You use three statements to control a cursor variable: OPEN – FOR , FETCH , and CLOSE . First, you OPEN a cursor variable FOR a multi-row query. Then, you FETCH rows from the result set. When all the rows are processed, you CLOSE the cursor variable.
What is type and Rowtype in Oracle?
%TYPE Vs. %RowType. %TYPE provides the data type of a variable or a database column to that variable. %ROWTYPE provides the record type that represents a entire row of a table or view or columns selected in the cursor.
What is strong ref cursor in Oracle?
A ref cursor which has fixed return type is called a Strong Ref Cursor in Oracle Database. Because of fixed return type, strong ref cursors can only be used selectively. For instance with those SELECT statements that return the result whose datatype matches with the one that you have fixed during cursor’s declaration.
What is variable substitution?
10.4. 6 Details of Variable Substitution. Part of ordinary shell syntax is the use of ‘ $ variable ‘ to substitute the value of a shell variable into a command. This is called variable substitution, and it is one part of doing word expansion.
In what case are substitution variables used for?
Substitution variables allow you to write generic SQL*Plus scripts. They allow you to mark places in a script where you want to substitute values at runtime.
How do I pass one cursor to another cursor?
The trick to declaring a cursor within a cursor is that you need to continue to open and close the second cursor each time a new record is retrieved from the first cursor. That way, the second cursor will use the new variable values from the first cursor.
Can we pass cursor as parameter?
A cursor is passed a parameter in very much the same way a procedure is passed a parameter except that the parameter can only be IN mode. Like the procedure, the cursor definition will declare an unconstrained datatype for the passed variable.
What are cursor variables?
A cursor variable is a cursor that contains a pointer to a query result set. The result set is determined by execution of the OPEN FOR statement using the cursor variable. A cursor variable, unlike a static cursor, is not associated with a particular query.
How many attributes does every explicit cursor and cursor variable have?
Every explicit cursor and cursor variable has four attributes: %FOUND , %ISOPEN %NOTFOUND , and %ROWCOUNT . When appended to the cursor or cursor variable, these attributes return useful information about the execution of a data manipulation statement. For more information, see “Using Cursor Expressions”.
How do I control a cursor variable in SQL?
Currently, cursor variables are subject to several restrictions. See “Restrictions on Cursor Variables”. You use three statements to control a cursor variable: OPEN-FOR, FETCH, and CLOSE. First, you OPENa cursor variable FORa multi-row query. Then, you FETCHrows from the result set. When all the rows are processed, you CLOSEthe cursor variable.
What is cursor in PL/SQL?
What is CURSOR in PL/SQL? A Cursor is a pointer to this context area. Oracle creates context area for processing an SQL statement which contains all information about the statement. PL/SQL allows the programmer to control the context area through the cursor. A cursor holds the rows returned by the SQL statement.
How do I reduce the number of cursors in SQL?
When SQL statements use literals rather than bind variables, setting the CURSOR_SHARING initialization parameter to FORCE enables the database to replace literals with system-generated bind variables. Using this technique, the database can sometimes reduce the number of parent cursors in the shared SQL area.
What is a shared cursor in Oracle?
A shared SQL area that is accessed by multiple statements is known as a shared cursor . Oracle Database automatically determines whether the SQL statement or PL/SQL block being issued is textually identical to another statement currently in the library cache, using the following steps: The text of the statement is hashed.