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  • 关于Oracle过程,函数的经典例子及解析

    一,Oracle中的过程,函数

    对于oracle中的过程和函数,个人觉得可以化为一类,因为它们在写法上并没有什么的不同。公式无非就是

    create or replace Package_name(paramater1 in type,paramater2 in type,out_message out type)

    is

    locate_paramater1 type;

    locate_paramater2 type;

    begin

    begin

    select sth into locate_paramater1  from table_name where 。。。。

    exception

    when no_data_found then

      locate_paramater1:=' ';

    out_message:='Some Information to user to look'; 

    end

    begin

    select sth into locate_paramater2  from table_name where 。。。。

    exception

    when no_data_found then

      locate_paramater2:=' ';

    out_message:='Some Information to user to look'; 

    end

    end

    总而言之,言而总之:包声明,私有数据神马的在紧跟is之后。接着就是一串的begin......exception....end;

    函数

    create or replace function_name(paramater1 in type,paramater2 in type)

    return return_type;

    is

    locate_paramater1 type;

    locate_paramater2 type;

    out_message return_type;

    begin

    begin

    select sth into locate_paramater1  from table_name where 。。。。

    exception

    when no_data_found then

      locate_paramater1:=' ';

    out_message:='Some Information to user to look';

    return out_message;

    when others then

    out_message:='Error';

    return out_message;

    end

    begin

    select sth into locate_paramater2  from table_name where 。。。。

    exception

    when no_data_found then

      locate_paramater2:=' ';

    out_message:='Some Information to user to look';

    return out_message;

    end

    end

    下面奉上

    /* 练习一:
    函数:
    作一函数,完成下面的功能:
    输入姓名,课程名,成绩
    该过程完成对SC表的插入或修改操作,
    若插入成功,返回成功信息,
    若该选课信息已经存在,则修改其成绩为输入的成绩,
    若遇系统错误,返回错误信息*/
    /*
    过程:
    建立过程,当传入学号和选课门数,首先判断SC_Number表是否存在
    ,若不存在则创建该表格(包括学号和选修门数两列),
    将传入值插入或修改到SC_Number表中(该生不存在则插入,若存在则修改其选课门数)*/

    复制代码

    create or replace procedure inOrUp_Sc_Number(ip_sno in number,ip_courseCount in number) 
    is
    tempt_count number(4);
    e_sc_number number(4);
    begin

    begin
    --tab 是一个系统表,存储当前用户下所拥有的表信息
    select 1 into e_sc_number from tab where tname='SC_Number';
    exception
    when no_data_found then
    --注意对私有数据的赋值方式!!!!
    e_sc_number:=0;
    when others then
    dbms_output.put_line(sqlerrm);
    return;
    end;
    --endOfBegin
    if e_sc_number=0 then
    --这个是动态sql,因为在执行这句话之前不知道是否要执行,所以要用动态的
    --动态sql的语法:execute immediate 'sql statement'
    execute immediate
    'create table SC_Number(sno number(5) primary key,cnum number(3) )';
    execute immediate
    'insert into SC_Number select sno,count(*) from sc group by sno';
    commit;
    end if;

    begin
    --这个也是动态sql
    --需要注意的是给动态sql,动态的赋值,=:number useing paramater
    execute immediate
    'select 1 from SC_Number where sno=:1' into tempt_count using trim(ip_sno);
    exception
    when no_data_found then
    tempt_count:=0;
    when others then
    dbms_output.put_line(sqlerrm);
    return;
    end;
    --endOfBegin
    if tempt_count=1 then
    begin
    execute immediate
    --这个还是动态sql
    --需要注意的是给动态sql,动态的赋值,=:number useing paramater
    'update SC_Number set cnum=:1 where sno=:2'using ip_courseCount,trim(ip_sno);
    commit;
    exception
    when others then
    dbms_output.put_line(sqlerrm);
    return;
    end;
    end if;
    --endOfIf
    if tempt_count=0 then
    begin
    execute immediate
    --为神马这么多动态sql
    'insert into SC_Number values(:1,:2)'using ip_sno,ip_courseCount;
    commit;
    exception
    when others then
    dbms_output.put_line(sqlerrm);
    return;
    end;
    end if;
    --endOfIf
    end;

    复制代码

    create or replace function func_InsetOrUpdateSc(ip_sname in varchar2,ip_cname in varchar2,ip_grade in varchar2)
    --这个是函数的返回类型
    return varchar2
    is
    student_num student.sno%type;
    course_num course.cno%type;
    out_messsage varchar2(30);--注意私有数据声明时要标注大小
    tempt_count number(4);
    begin

    begin
    select sno into student_num from student where student.snmae=ip_sname;
    exception
    when no_data_found then
    student_num:='';
    out_messsage:='No such a Student';
    return out_messsage;
    when others then
    out_messsage:='Error';
    return out_messsage;
    end;
    --endOfBegin
    begin
    select cno into course_num from course where course.cname=ip_cname;
    exception
    when no_data_found then
    course_num:='';--私有数据的赋值方法和过程类似
    out_messsage:='No such a Course';
    return out_messsage;
    when others then
    out_messsage:='Error';
    return out_messsage;
    end;
    --endOfBegin
    begin
    select 1 into tempt_count from sc where sc.sno=student_num and sc.cno=course_num;
    exception
    when no_data_found then
    tempt_count:=0;
    when others then
    out_messsage:='Error';
    return out_messsage;
    end;
    --endOfBegin
    if tempt_count=1 then
    begin
    update sc set sc.grade=ip_grade where sc.sno=student_num and sc.cno=course_num;
    --注意下面的commit语句,在update,insert时,不要忘记了哦
    commit;
    out_messsage:='Update Success';
    return out_messsage;
    exception
    when others then
    out_messsage:='Error';
    return out_messsage;
    end;
    end if;
    --endOfIf
    if tempt_count=0 then
    begin
    insert into sc values(student_num,course_num,ip_grade);
    commit;
    out_messsage:='Insert Success!';
    return out_messsage;
    exception
    when others then
    out_messsage:='Error';
    return out_messsage;
    end;
    end if;
    --endOfIf
    end;
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  • 原文地址:https://www.cnblogs.com/zhukezhuke/p/2344050.html
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