Contents
How many types of cursors are available in PL SQL?
PL/SQL has two types of cursors: implicit cursors and explicit cursors.
Why cursors are used in PL SQL?
The major function of a cursor is to retrieve data, one row at a time, from a result set, unlike the SQL commands which operate on all the rows in the result set at one time. Cursors are used when the user needs to update records in a singleton fashion or in a row by row manner, in a database table.
What is record type in PL SQL?
A record type is a composite data type that consists of one or more identifiers and their corresponding data types. You can create user-defined record types by using the TYPE IS RECORD statement within a package or by using the CREATE TYPE (Object) statement.
How do I create a trigger in PL SQL?
Syntax for creating trigger:
- CREATE [OR REPLACE ] TRIGGER trigger_name.
- {BEFORE | AFTER | INSTEAD OF }
- {INSERT [OR] | UPDATE [OR] | DELETE}
- [OF col_name]
- ON table_name.
- [REFERENCING OLD AS o NEW AS n]
- [FOR EACH ROW]
- WHEN (condition)
How do you create a record in PL SQL?
The %ROWTYPE attribute, used to declare PL/SQL variables of type record with fields that correspond to the columns of a table or view, is supported by the data server. Each field in a PL/SQL record assumes the data type of the corresponding column in the table. A record is a named, ordered collection of fields.
How do you create a cursor in SQL?
Follow these steps to create a cursor: Associate a cursor with a resultSet of a T-SQL statement, and define the characteristics of the cursor, such as how the rows are going to be retrieved, and so forth. Execute the T-SQL statement to populate the cursor. Retrieve the rows in the cursor.
What is the cursor variable in SQL?
Cursor variables (PL/SQL) 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.
What is Oracle SQL cursor?
The Cursor is a handle (name or a pointer) for the memory associated with a specific statement. A cursor is basically an Area alocated by Oracle for executing the Sql Statements. Oracle Uses an Implicit Cursor statement for a single row query and Explicit Cursor for a multi row query.
What is the Oracle cursor?
A cursor is a pointer that points to a result of a query . PL/SQL has two types of cursors: implicit cursors and explicit cursors. Whenever Oracle executes an SQL statement such as SELECT INTO, INSERT, UPDATE, and DELETE, it automatically creates an implicit cursor.