转账 存储过程

alter proc usp_trancMoney
@from char(4),
@to char(4),
@money money ,
@isok int output 
as 
begin

    declare @have money =-1 ,@iscunzai int =0
    select @have=balance from bank where cId=@from
    
    --看看要存入的账号是否存在

     if not exists(
        select cid from bank where cId=@to)
         begin
            set @isok=4 --要转入的账号不存在
            return
         end

    if @have<0  --要转出的账号是否存在
        begin
            set @isok=3  ---wu zhang hao
        end
    else 
        begin 
            if    @have-@money<10
                begin
                    print @have
                    set @isok=2 --wu ge bu zu 
                end
                
            else
                begin
                    print '转账kaishi '
                
                    --开始转账
                     
                    begin transaction
                        update  bank set balance=balance-@money where cId=@from
                        set @isok=@isok+@@error 
                        update bank set balance=balance+@money where cId=@to
                        set @isok=@isok+@@error 
                        if @isok>0
                            begin
                             set @isok=1--error
                              rollback
                            end
                        else
                            begin
                                set @isok=0  --ok
                                commit tran
                            end
                    
                end
            
        end

end    

---------测试
declare @out int
declare @str nvarchar(33)
exec usp_trancMoney @from='0005',@to='0003' ,@money=10 ,@isok=@out output


select @str=
        case @out
            when 0 then '成功了'
            when 1 then  '失败了'
            when 2 then  '余额不足'
            when 3 then  '不存在的账号(转出)'
            when 4 then  '要转入的账号不存在'
            else '未知错误'
        end
print @str

ado.net调用存储过程

在sqlhelper中

  //1.执行增（insert）、删(delete)、改(update)的方法
        //ExecuteNonQuery()
        public static int ExecuteNonQuery(string sql, CommandType cmdType, params SqlParameter[] pms)
        {
            using (SqlConnection con = new SqlConnection(conStr))
            {
                using (SqlCommand cmd = new SqlCommand(sql, con))
                {
                    //cmd.CommandType = CommandType.Text;//这个是默认的，当使用sql语句的时候传入这个
                    //cmd.CommandType = CommandType.StoredProcedure;//存储过程
                    cmd.CommandType = cmdType;
                    if (pms != null)
                    {
                        cmd.Parameters.AddRange(pms);
                    }
                    con.Open();
                    return cmd.ExecuteNonQuery();
                }
            }
        }

调用

            SqlParameter[] pms = new SqlParameter[]{
            new SqlParameter("@from",SqlDbType.Char,4){ Value=from},
            new SqlParameter("@to",SqlDbType.Char,4){ Value=to},
            new SqlParameter("@money",SqlDbType.Money){ Value=money},
            new SqlParameter("@isok",SqlDbType.Int){ Direction=ParameterDirection.Output}
            };

            //调用存储过程实现转账
            SqlHelper.ExecuteNonQuery("usp_trancMoney", CommandType.StoredProcedure, pms);
            int result = Convert.ToInt32(pms[3].Value);