PL/SQL匿名塊詳解
摘要：PL/SQL是Oracle下的腳本開發語言，是爲了解決數據下一些複雜的應用而設計的。一些複雜的應用，僅靠一條SQL語句並不能完成，爲了解決這個問題，各個數據庫產品都設計了自己的腳本編程語言，Oracle下叫做PL/SQL，SQL Server下叫做Transact SQL。
--HelloWorld開始set serveroutput on;begin dbms_output.put_line('Hello World!!!');end;/--最簡單的語句塊declare v_word varchar(20);begin v_word:='Hello World!!!'; dbms_output.put_line(v_word);end;/--語句塊的組成declare v_num number:=0;begin v_num:=2/v_num; dbms_output.put_line(v_num);exception when others then dbms_output.put_line('error');end;/--變量的聲明declare v_temp number(1); v_count binary_integer :=0; v_sal number(7,2):=3000.00; v_date date:=sysdate; v_pi_constrant number(3,2):=3.14; v_valid
boolean :=false; v_name varchar2(20) not
null :='My Name';begin dbms_output.put_line('v_temp value:'
|| v_temp);end;/--變量聲明,使用%type屬性declare v_empno number(4); v_empno2 emp.empno%type; v_empno3 v_empno2%type;begin dbms_output.put_line('test...');end;/--簡單變量賦值declare v_name varchar2(20); v_sal number(7,2); v_sal2 number(7,2); v_valid
boolean :=
false; v_date date;begin v_name :=
'My Name'; v_sal :=
23.77; v_sal2 :=
23.77; v_valid := (v_sal=v_sal2); v_date := to_date('2010-08-04 22:58:58','YYYY-MM-DD HH24-MI-SS');end;/--table變量類型declare type type_table_emp_empno is table of emp.empno%type index by binary_integer; v_empnos type_table_emp_empno;begin v_empnos(0) :=
7369; v_empnos(1) :=
7839; v_empnos(-1) :=
9999; dbms_output.put_line(v_empnos(-1));end;/--Record變量類型declare type type_record_dept is record ( deptno dept.deptno%type, dname dept.dname%type, loc dept.loc%type ); v_temp type_record_dept;begin v_temp.deptno :=
50; v_temp.dname :=
'dname'; v_temp.loc :=
'BJ'; dbms_output.put_line(v_temp.deptno ||
' ' || v_temp.dname);end;/--使用%rowtype 聲明record變量declare v_temp dept%rowtype;begin v_temp.deptno :=
50; v_temp.dname :=
'dname'; v_temp.loc :='BJ'; dbms_output.put_line(v_temp.deptno ||
' ' || v_temp.dname);end;/--SQL語句應用declare
v_ename emp.ename%type; v_sal emp.sal%type;begin select ename,sal into v_ename,v_sal from emp where empno=7900; --select ename,sal into v_ename,v_sal from emp where deptno=30; dbms_output.put_line(v_ename ||
' ' || v_sal);end;/--SQL語句應用declare
v_emp emp%rowtype;begin select * into v_emp from emp where empno=7369; dbms_output.put_line(v_emp.ename);end;/--SQL語句應用create table dept2( deptno number, dname varchar2(50), loc varchar2(50));declare v_deptno dept.deptno%type :=
50; v_dname dept.dname%type :='My Name'; v_loc dept.loc%type :=
'BJ';begin insert into dept2 values(v_deptno,v_dname,v_loc);end;/select * from dept2;--drop table dept2;--SQL語句應用declare v_deptno dept2.deptno%type :=
30; v_count number;begin select deptno into v_deptno from dept2 where deptno=50; select count(*) into v_count from dept2; dbms_output.put_line('deptno:'
|| v_deptno); dbms_output.put_line('count:'
|| v_count); dbms_output.put_line(sql%rowcount ||
'條記錄被影響...');end;/--使用DDL語句begin execute immediate
'create table T(nnn varchar2(20))';end;/drop table T;--選擇語句declare v_sal emp.sal%type;begin select sal into v_sal from emp where empno=7369; if(v_sal <
1200)then dbms_output.put_line('low'); elsif(v_sal <
2000) then dbms_output.put_line('middle'); else dbms_output.put_line('high'); end
if;end;/--循環語句declare i binary_integer :=
1;begin loop dbms_output.put_line('=='
|| i); i := i+1; exit when(i>=11); end loop;end;/--循環語句declare j binary_integer :=
1;begin while
j<11
loop dbms_output.put_line('=='
|| j); j := j+1; end loop;end;/--循環語句begin for
k in 1..10
loop dbms_output.put_line('=='
|| k); end loop; for
k in reverse 1..10
loop dbms_output.put_line('=='
|| k); end loop;end;/--錯誤處理declare
v_temp number(4);begin select empno into v_temp from emp where deptno=10;exception when too_many_rows then dbms_output.put_line('太多記錄了...'); when others then dbms_output.put_line('error...');end;/--錯誤處理declare v_temp number(4);begin select empno into v_temp from emp where empno=2222;exception when no_data_found then dbms_output.put_line('沒有數據...'); when others then dbms_output.put_line('error...');end;/--遊標declare cursor c is select * from emp; v_emp c%rowtype;begin open c; fetch c into v_emp; dbms_output.put_line(v_emp.ename); close c;end;/--遊標declare cursor c is select * from emp; v_emp c%rowtype;begin open c; loop fetch c into v_emp; exit when(c%notfound); dbms_output.put_line(v_emp.ename); end loop; close c;end;/--遊標declare cursor c is select * from emp; v_emp c%rowtype;begin open c; fetch c into v_emp; while(c%found)loop dbms_output.put_line(v_emp.ename); fetch c into v_emp; end loop; close c;end;/--遊標declare cursor c is select * from emp;begin for
v_emp in c loop dbms_output.put_line(v_emp.ename); end loop;end;/--帶參數的遊標declare cursor c(v_deptno emp.deptno%type, v_job emp.job%type) is
select ename,sal from emp where deptno=v_deptno and job=v_job; --v_temp c%rowtype;begin --open c(30,'clerk'); for
v_temp in c(30,'CLERK') loop dbms_output.put_line(v_temp.ename ||
' ' || v_temp.sal); end loop;end;/--可以更新的遊標create table emp2 as( select * from emp);drop table emp2;declare cursor c is select * from emp2
for update; --v_temp c%rowtype;begin for
v_temp in c loop if(v_temp.sal <
2000)then update emp2 set sal=sal*2
where current of c; elsif(v_temp.sal =5000)then delete from emp2 where current of c; end
if; end loop; commit;end;/ |