if...else
set serverout on;
declare n number:=1;
v varchar2(20):='world';
begin
dbms_output.put_line('hello'||n||v);
end;
set serverout on;
declare emp_count number;
begin
select count(*) into emp_count from emp where sal>=3000;
if emp_count>0 then
dbms_output.put_line('有'||emp_count||'个员工的基本薪资大于等于3000');
else
dbms_output.put_line('没有员工的基本薪资大于等于3000');
end if;
end;
set serverout on;
declare emp_count number;
begin
select count(*) into emp_count from emp where sal>=3000;
if emp_count=1 then
dbms_output.put_line('有1个员工的基本薪资大于等于3000');
else if emp_count>1 then
dbms_output.put_line('有超过1个员工的基本薪资大于等于3000');
else
dbms_output.put_line('没有员工的基本薪资大于等于3000');
end if;
end if;
end;
case...when
set serverout on;
declare emp_count number;
begin
select count(*) into emp_count from emp where sal>=3000;
case emp_count
when 0 then dbms_output.put_line('没有员工的基本薪资大于等于3000');
when 1 then dbms_output.put_line('有1个员工的基本薪资大于等于3000');
when 2 then dbms_output.put_line('有2个员工的基本薪资大于等于3000');
when 3 then dbms_output.put_line('有3个员工的基本薪资大于等于3000');
else dbms_output.put_line('超过3个员工的基本薪资大于等于3000');
end case;
end;
无条件循环loop
set serverout on;
declare g_id number:=2;
g_losal number;
g_hisal number;
begin
loop
if(g_id>4) then
exit;
end if;
select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id;
dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || ',最高薪资:' || g_hisal);
g_id:=g_id+1;
end loop;
end;
while循环
set serverout on;
declare g_id number:=2;
g_losal number;
g_hisal number;
begin
while g_id<5 loop
select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id;
dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || ',最高薪资:' || g_hisal);
g_id:=g_id+1;
end loop;
end;
for循环
set serverout on;
declare g_losal number;
g_hisal number;
begin
for g_id in 2..4 loop
select losal,hisal into g_losal,g_hisal from salgrade where grade=g_id;
dbms_output.put_line(g_id || '等级的最低薪资'|| g_losal || ',最高薪资:' || g_hisal);
end loop;
end;