PL/SQL编程—变量

SQL> declare
  2  c_tax_rate number(3,2):=0.03;
  3  v_name varchar2(20);
  4  v_passwd varchar2(20);
  5  v_sale number(7,2);
  6  v_tax_sale number(7,2);
  7  begin
  8  select name,passwd,salary into v_name,v_passwd,v_sale from mytest where id=&inpt;
  9  v_tax_sale:=v_sale*c_tax_rate;
 10  dbms_output.put_line('name:'||v_name||' passwd:'||v_passwd||' taxsale:'||v_tax_sale);
 11  end;
 12  /
 
name:123 passwd:123 taxsale:3
 
PL/SQL procedure successfully completed

在声明变量的时候可以设置类型为动态的取表中的字段的类型一致

SQL> insert into mytest values('4','125555','passwd','50');
 
1 row inserted
 
SQL> select * from mytest;
 
ID    NAME                 PASSWD                                                                                         SALARY
----- -------------------- -------------------- --------------------------------------------------------------------------------
1     123                  123                                                                                               100
2     gaodingle!!!!        123                                                                                               100
3     gagaga               123                                                                                               100
4     125555               passwd                                                                                             50
 
SQL>
SQL> declare
  2  c_tax_rate number(3,2):=0.03;
  3  v_name varchar2(4);
  4  v_passwd varchar2(20);
  5  v_sale number(7,2);
  6  v_tax_sale number(7,2);
  7  begin
  8  select name,passwd,salary into v_name,v_passwd,v_sale from mytest where id=&inpt;
  9  v_tax_sale:=v_sale*c_tax_rate;
 10  dbms_output.put_line('name:'||v_name||' passwd:'||v_passwd||' taxsale:'||v_tax_sale);
 11  end;
 12  /
 
declare
c_tax_rate number(3,2):=0.03;
v_name varchar2(4);
v_passwd varchar2(20);
v_sale number(7,2);
v_tax_sale number(7,2);
begin
select name,passwd,salary into v_name,v_passwd,v_sale from mytest where id=4;
v_tax_sale:=v_sale*c_tax_rate;
dbms_output.put_line('name:'||v_name||' passwd:'||v_passwd||' taxsale:'||v_tax_sale);
end;
 
ORA-06502: PL/SQL: 数字或值错误 :  字符串缓冲区太小
ORA-06512: 在 line 9
 
SQL>
SQL> declare
  2  c_tax_rate number(3,2):=0.03;
  3  v_name mytest.name%type;
  4  v_passwd varchar2(20);
  5  v_sale number(7,2);
  6  v_tax_sale number(7,2);
  7  begin
  8  select name,passwd,salary into v_name,v_passwd,v_sale from mytest where id=&inpt;
  9  v_tax_sale:=v_sale*c_tax_rate;
 10  dbms_output.put_line('name:'||v_name||' passwd:'||v_passwd||' taxsale:'||v_tax_sale);
 11  end;
 12  /
 
name:125555 passwd:passwd taxsale:1.5
 
PL/SQL procedure successfully completed

SQL> declare
  2  --定义一个pl/sql记录类型叫做 test_record_type 可以理解为定义一个类，这个类型中包括了name,passwd,salary
  3  type test_record_type is record (name mytest.name%type,passwd mytest.passwd%type,salary_gaga mytest.salary%type);
  4  --定义一个变量这个变量是test_record_type类型 好比类new一个对象
  5  sp_record test_record_type;
  6  begin
  7  select name,passwd,salary into sp_record from mytest where id=&inpt;
  8  dbms_output.put_line('name:'||sp_record.name||' salary:'||sp_record.salary_gaga);
  9  end;
 10  /
 
name:123 salary:100

SQL> declare
  2  type sp_test_table is table of mytest.name%type index by binary_integer;
  3  test_table sp_test_table;
  4  begin
  5  select name into test_table(0) from mytest where id=&inpt;
  6  dbms_output.put_line('name:'||test_table(0));
  7  end;
  8  /
 
name:gagaga
 
PL/SQL procedure successfully completed