What Is a Cursor

Q

What Is a Cursor? - Oracle DBA FAQ - Working with Cursors in PL/SQL

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A

A cursor looks like a variable, but it is not a variable. A cursor looks like a procedure, but it is not a procedure. A cursor is a cursor. It is a logical representation of a resource connects to a set of data rows related to a DML statement. A cursor is consists of:

A DML statement with or without parameters.
A status to indicate whether it is connected or not.
A pointer to indicate the current row in the resource set.
A number of attributes about the cursor, like FOUND, NOTFOUND and ROWCOUNT.

2007-04-29, 5205👍, 0💬

How To Test NULL Values
How To Test NULL Values? - Oracle DBA FAQ - Understanding PL/SQL Language Basics There ate two special comparison operators you can use on NULL values: "variable IS NULL" - Returns TRUE if the variable value is NULL. "variable IS NOT NULL" - Return TRUE if the variable value is not NULL. The followi... 2007-04-29, 6082👍, 0💬

How To Use "FOR" Statements
How To Use "FOR" Statements? - Oracle DBA FAQ - Understanding PL/SQL Language Basics If you have a block of codes to be executed repeatedly over a range of values, you can use the "FOR ... LOOP" statement. Here is a sample script on FOR statements: DECLARE total NUMBER := 0; BEGIN FOR i IN 1..10 LOO... 2007-04-29, 5681👍, 0💬

How To Use "WHILE" Statements
How To Use "WHILE" Statements? - Oracle DBA FAQ - Understanding PL/SQL Language Basics If you have a block of codes to be executed repeatedly based a condition, you can use the "WHILE ... LOOP" statement. Here is a sample script on WHILE statements: DECLARE total NUMBER; BEGIN total := 0; WHILE tota... 2007-04-29, 5489👍, 0💬

How Many Types of Cursors Supported in PL/SQL
How Many Types of Cursors Supported in PL/SQL? - Oracle DBA FAQ - Working with Cursors in PL/SQL PL/SQL supports two types of cursors: The implicit cursor - A single default cursor that automatically connects to the last DML statement executed. Explicit cursors - User defined cursors with specific D... 2007-04-29, 5482👍, 0💬

What Is NULL in PL/SQL
What Is NULL in PL/SQL? - Oracle DBA FAQ - Understanding PL/SQL Language Basics NULL is a reserved key word and it stands for two things in PL/SQL: NULL is an executable statement, and means doing nothing. NULL is a data balue, and means no value. The following sample script shows you examples of us... 2007-04-29, 5233👍, 0💬

What Is a Cursor
What Is a Cursor? - Oracle DBA FAQ - Working with Cursors in PL/SQL A cursor looks like a variable, but it is not a variable. A cursor looks like a procedure, but it is not a procedure. A cursor is a cursor. It is a logical representation of a resource connects to a set of data rows related to a DML... 2007-04-29, 5206👍, 0💬

How To Loop through Data Rows in the Implicit Curosr
How To Loop through Data Rows in the Implicit Curosr? - Oracle DBA FAQ - Working with Cursors in PL/SQL You use the FOR ... IN ... LOOP statement to loop through data rows in the implicit cursor as the following syntax: FOR row IN dml_statement LOOP (statement block with row.field) END LOOP; Here "r... 2007-04-29, 5195👍, 0💬

How To Use Attributes of the Implicit Cursor
How To Use Attributes of the Implicit Cursor? - Oracle DBA FAQ - Working with Cursors in PL/SQL Right after executing a DML statement, you retrieve any attribute of the implicit cursor by using SQL%attribute_name, as shown in the following tutorial exercise: CREATE TABLE student (id NUMBER(5) PRIMAR... 2007-04-29, 5185👍, 0💬

How To Define an Explicit Cursor
How To Define an Explicit Cursor? - Oracle DBA FAQ - Working with Cursors in PL/SQL An explicit cursor must be defined in the declaration part of a procedure or function with the CURSOR ... IS statement as shown in the following sample script: DECLARE CURSOR c_list IS SELECT * FROM countries; CURSOR... 2007-04-29, 5130👍, 0💬

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