Cursor For Loop: Oracle provides another loop-statements to control loops specifically for cursors. This statements is a variation of the basic FOR loop, and it is known as cursor for loops. Syntax: FOR VARIABLE IN CURSORNAME LOOP END LOOP Parameterized Cursors.

Postgresql Cursor For Loop Example Python
Postgresql Cursor For Loop Example Java

String sum and receiving multiple row result query in comma separated single row.
Execution result of the query in Postgresql Function

CREATE TABLE mem_reg_mcg
(
id serial NOT NULL,
br_id character varying(3) NOT NULL,
mid character varying(50) NOT NULL,
'name' character varying(200)
);

In execution part, the declared cursor is setup in the FOR loop and the loop variable 'I' will behave as cursor variable in this case. Example 1: In this example, we will project all the employee name from emp table using a cursor-FOR loop. Example: Returning a REF CURSOR from a procedure (PL/SQL) This example demonstrates how to define and open a REF CURSOR variable, and then pass it as a procedure parameter. The cursor variable is specified as an IN OUT parameter so that the result set is made available to the caller of the procedure.

CREATE OR REPLACE FUNCTION get_all_single_row_mem(m_id integer)
RETURNS character varying AS
$BODY$
DECLARE
_record RECORD;
alert_mesg character varying(2000);
IN_VAR1 character varying(50);

Postgresql Cursor For Loop Example Python

BEGIN
alert_mesg := ';
--Define output columns
FOR _record IN select m.name from mem_reg_mcg m where id> $1 Loop

LOOP

Postgresql Cursor For Loop Example Java

IN_VAR1 := _record.name;
--Build output string For

alert_mesg := alert_mesg||IN_VAR1||', ';
END LOOP;
RETURN subString(alert_mesg,0,char_length(alert_mesg)-1);
--EXCEPTION -- WHEN OTHERS THEN -- RETURN 'No troubleshooting information at this time.';
END;
$BODY$ LANGUAGE 'plpgsql' VOLATILE
COST 100;
ALTER FUNCTION get_all_single_row_mem(m_id integer) OWNER TO postgres;

See Cursor example

PL/SQL cursor FOR loop has one great advantage of loop continued until row not found. In sometime you require to use explicit cursor with FOR loop instead of use OPEN, FETCH, and CLOSE statement.

FOR loop iterate repeatedly and fetches rows of values from database until row not found.

Explicit Cursor FOR LOOP Example

following one emp_information table:

EMP_NO	EMP_NAME	EMP_DEPT	EMP_SALARY
1	Forbs ross	Web Developer	45k
2	marks jems	Program Developer	38k
3	Saulin	Program Developer	34k
4	Zenia Sroll	Web Developer	42k

Display employee number wise first two employee details emp,

Example

cursor_for_loop.sql

Result

SQL>@cursor_for_loop
EMP_No: 1
EMP_Name: Forbs ross
EMP_Dept: Web Developer
EMP_Salary:45k
EMP_No: 2
EMP_Name: marks jems
EMP_Dept: Program Developer
EMP_Salary:38k
PL/SQL procedure successfully completed.