Detailed introduction to the use of various control statements in Oracle databases

Oracle DatabaseVariousControl statementThe usage is what we will introduce in this article, including some logical control statements, the use of Case when, the use of While, and the use of, next we will introduce this part one by one, hoping to help you.

Logical control statements in Oracle

 
 

  
  
If elsif else end if    
  
  
set serverout on;    
  
  
declare per_dep_count number;    
  
  
begin    
  
  
select count(*) into per_dep_count from emp;    
  
  
if per_dep_count>0 then    
  
  
dbms_output.put_line('Big Than 0');    
  
  
elsif per_dep_count>5 then <span style="font-size:24px;color:#ff0000;"><strong>--elsif not elseif!!!!     
  
  
</strong></span>                dbms_output.put_line('Big Than 5');    
  
  
else    
  
  
dbms_output.put_line('En?');    
  
  
end if;    
  
  
end;  
 
 

Use Case when in two ways

1)

 
 

  
  
declare per_dep_count number;    
  
  
begin    
  
  
select count(*) into per_dep_count from emp;    
  
  
case per_dep_count    
  
  
when 1 then    
  
  
dbms_output.put_line('1');    
  
  
when 2 then    
  
  
dbms_output.put_line('2');    
  
  
else    
  
  
dbms_output.put_line('else');    
  
  
end case;    
  
  
end;   
 
 

2)

 
 

  
  
declare per_dep_count number;    
  
  
begin    
  
  
select count(*) into per_dep_count from emp;    
  
  
case     
  
  
when per_dep_count=1 then    
  
  
dbms_output.put_line('1');    
  
  
when per_dep_count=2 then    
  
  
dbms_output.put_line('2');    
  
  
else    
  
  
dbms_output.put_line('else');    
  
  
end case;    
  
  
end;   
 
 

While usage

 
 

  
  
declare v_id number:=0;    
  
  
begin    
  
  
while v_id<5 loop    
  
  
v_idv_id:=v_id+1;    
  
  
dbms_output.put_line(v_id);    
  
  
end loop;    
  
  
end;   
 
 

For

 
 

  
  
declare v_id number:=0;    
  
  
begin    
  
  
for v_id in 1..5 loop    
  
  
dbms_output.put_line(v_id);    
  
  
end loop;    
  
  
end;  
 
 

The usage of various control statements in the Oracle database is introduced here. I hope this introduction will be helpful to you!