PL/SQL flow control statements-condition structure, cyclic structure

I. IF-THEN statement

The IF-THEN statement is the simplest IF statement.

Syntax:

 condition  ;

Example:

 :    v_score    ;

II. IF-THEN-ELSE statement

Compared with the IF-THEN statement, the IF-THEN-ELSE statement provides program exceptions when the conditions are not met.

Syntax:

 condition  ;

Example:

 :    v_score    ;

 

3. IF-THEN-ELSIF statement

This statement is used when multiple different conditions exist. Note that it is ELSIF, not ELSEIF.

Syntax:

 condition1  ;

Example:

 :    v_score      ;

 

Iv. CASE statements

The CASE statement is the control statement structure introduced after Oracle 9i.

Syntax:

 value1  value2  valuen  ;

Example:

 :      dbms_output.put_line(   dbms_output.put_line(   dbms_output.put_line(   dbms_output.put_line(   dbms_output.put_line(   dbms_output.put_line(   dbms_output.put_line( dbms_output.put_line( ;

 

1. LOOP

LOOP is the simplest LOOP. Use the EXIT statement to EXIT the loop.

Syntax:

 LOOP;

Example:

 :  v_num v_num        ;

 

2. WHILE-LOOP

When a WHILE-LOOP is executed, it first determines whether the LOOP condition is TRUE. When the condition is TRUE, it begins to execute the statements in the LOOP body.

Syntax:

 LOOP;

Example:

 :    v_num v_num;

 

3. FOR-LOOP

Compared with the WHILE-LOOP, the FOR-LOOP can clearly know the number of cycles and determine the LOOP range.

Syntax:

 loop_count   LOOP;

Example:

   i  ..;