Detailed explanation of Oracle implicit and explicit cursors

What is the cursor? It is a temporary storage space opened up in memory.

1.Oracle implicit cursor

Which implicit cursors are commonly used in 1.1Oracle

1.2 Oracle implicit cursor demonstration

-- implicit cursor (the table used is the emp table that comes with Oracle by default)-- sql%rowcount: affect the number of records sql%found: whether there are records that meet the conditions set serveroutput on;declarev_ename axiemp.ename% type begin select ename into v_ename from a_emp where empno=7788;if sql%found then dbms_output.put_line (v_ename); dbms_output.put_line (sql%rowcount); end if;end;/

Therefore, all of our database operations have cursors.

2.Oracle explicit cursor

2.1 explicit cursor syntax

Cursor cursor name is select statement

2.2Oracle explicit Vernier demonstration

-- explicit cursor declare-- create a cursor cursor cursor_a_emp is select empno,ename from aura emptiness;-- other variables v_empno astatemp.empno% type;-- employee number v_ename acuremp.ename% type;-- employee name v_rowcount number;-- number of employees begin-- Open cursor open cursor_a_emp -- calculate the number of records stored in the cursor select count (*) into v_rowcount from emp;-- cycle to fetch the data in the cursor, for i in 1..v_rowcount loop fetch cursor_a_emp into vault empnoscope vault name; dbms_output.put_line (v_empno); dbms_output.put_line (v_ename); dbms_output.put_line ('= ='); end loop -- close the cursor close cursor_a_emp;end;/

A cursor is the equivalent of a temporary table, which is stored in memory and released when it is finished.

2.3 explicit cursor properties

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