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局域网图书资料查询系统


 
 
§5.3  查询模块的实现
 
图5－3　查询窗口
　　
该窗口（w_main）控件列表如下：
 风  格 控件名 说  明
显示项 Group Box gb_1    ------
资料名称 Check Box cbx_1 Checked:true
作者 Check Box cbx_2 Checked:true
出版社 Check Box cbx_3 Checked:true
出版日期 Check Box cbx_4 Checked:false
类别 Check Box cbx_5 Checked:true
购买日期 Check Box cbx_6 Checked:false
ISBN Check Box cbx_7 Checked:false
保管人 Check Box cbx_8 Checked:true
备注 Check Box cbx_9 Checked:false
全选 Check Box cbx_10 选择全部显示项
检索 Picture Box pb_1 模糊查询检索
插入 Picture Box pb_2 插入一条记录
删除 Picture Box pb_3 删除一条记录
检索 Picture Box pb_4 组合查询检索
全部记录 Picture Box pb_5 检索全部记录
退出 Picture Box pb_6 退出查询界面
修改 Picture Box pb_7 进入编辑模式
插入 Picture Box pb_8 插入一条查询条件
删除 Picture Box pb_9 删除一条查询条件
存盘 Picture Box pb_10 修改后的数据存盘
打印 Picture Box pb_11 打印查询结果报表
存为默认显示项 Picture Box pb_12 将显示项存为当前用户默认
------ Single line edit sle_1 查询内容输入（字符型）
------ Edit mask em_1 查询内容输入（日期型）
------ Static text st_1 显示当前用户名
------ Picture P_1 修改按钮装饰
------ Picture P_2 Gb_1显示装饰
------ Picture P_3 显示当前用户头像
------ Drop down list box ddlb_1 查询项选择
------ Drop down list box ddlb_2 查询操作符选择
------ Tab control tab_1 共有三个tabpage頁tabpage1:模糊查询tabpage2:组合查询tabpage3:

更新打印
------ Datawindows control dw_1 对应数据窗口d_information图书信息检索
------ Datawindows control dw_2 对应数据窗口d_query_condition查询条件检索
 Command button Cb_2 模糊查询操作符英－中转换
表5－2　查询模块控件信息表
控件：w_main　　　事件（event）：open　　Script of open
string mode,p,xs,headboolean xs_item[10]integer idw_1.settransobject(sqlca)dw_1.

Retrieve()//打开窗口显示全部记录sj_check=0//为检索窗口排序变量赋初值st_1.text=user//

在查询窗口右上角显示当前用户名SELECT "keeper"."display_item",           "keeper"."

head_picture"  INTO :xs,        :head  FROM "keeper"  WHERE "keeper"."name" = :user;

//从用户表中读出当前用户的头像值及显示像值并分别赋值给变量 file://有头像的用户则显示

在查询窗口右上角if isnull(head) thenp_3.visible=false   else   p_3.picturename=

headend if ////将当前用户查询显示项变量读出并赋值给每个查询显示控件for i=1 to 8 if

Mid (xs, i, 1)='0' then  xs_item[i]=false else  xs_item[i]=true end ifend for////给每

个对应的CHECKBOX赋值，确实是勾还是叉cbx_2.checked = xs_item[1]cbx_3.checked =

xs_item[2]cbx_4.checked = xs_item[3]cbx_5.checked = xs_item[4]cbx_6.checked =

xs_item[5]  cbx_7.checked = xs_item[6]  cbx_8.checked = xs_item[7]cbx_9.checked =

xs_item[8]  ////对应的数据窗口显示情况dw_1.object.id.visible = falsedw_1.object.name

.visible = truedw_1.object.author.visible = cbx_2.checkeddw_1.object.

publishing_house.visible = cbx_3.checkeddw_1.object.publishing_date.visible = cbx_4.

checkeddw_1.object.sort.visible = cbx_5.checkeddw_1.object.buy_date.visible = cbx_6.

checkeddw_1.object.isbn.visible = cbx_7.checkeddw_1.object.keeper.visible = cbx_8.

checkeddw_1.object.memo.visible = cbx_9.checked////将查询数据窗口设为只读dw_1.Object

.DataWindow.ReadOnly="Yes"
                                                                                     

                                                                                     

                                                                                     

        
控件：pb_12 “存为默认显示选项”　事件（event）：clicked　　Script of clicked
boolean check[10]integer i,answerstring xs_item[10]string

xs_content,question_text,tempquestion_text="将当前显示项存为"+user+"用户的默认显示项

?"answer=messagebox('提示!',question_text,question!,YesNoCancel!)choose case answer

case 1  file://将当前对应的CHECEKBOX选项记录下来check[1]=cbx_2.checked      check[2]

=cbx_3.checked      check[3]=cbx_4.checked      check[4]=cbx_5.checked      check[5]

=cbx_6.checked      check[6]=cbx_7.checked      check[7]=cbx_8.checked      check[8]

=cbx_9.checked//  file://将显示项转化为01的显示，存入数组变量      xs_content=''     

for i = 1 to 8   if check[i]=true then        xs_item[i]='1'   else    xs_item[i]='0'

  end if   xs_content=xs_content+xs_item[i]  end for//      file://修改用户表中显示项

的值      UPDATE "keeper"        SET "display_item" = :xs_content        WHERE "

keeper"."name" = :user;　　　choose case SQLCA.sqlcode   case -1         messagebox("

错误!","error:"+&     string(sqlca.sqldbcode)+&     "information:"+sqlca.sqlerrtext) 

                messagebox('提示','修改成功!')     commit;         case 100        

messagebox('!','修改失败!')     end choose case 2 returncase 3 returnend choose
      
 
 
 
 
 

5.3.1  模糊（分类）查询的实现
 
图5－4　模糊查询窗口
控件：ddlb_1 　事件（selectionchanged）：　　Script  of  Selectionchanged
file://清空历史查询内容em_1.selecttext(1,len(em_1.text))em_1.clear()sle_1.selecttext

(1,len(sle_1.text))sle_1.clear()//运算符随查询内容的改变而改变if ddlb_1.text= '出版日

期' or ddlb_1.text='购买日期' then ddlb_2.deleteitem(ddlb_2.FindItem("包含", 2))

ddlb_2.deleteitem(ddlb_2.FindItem("不包含", 2)) ddlb_2.deleteitem(ddlb_2.FindItem("小

于等于", 2)) ddlb_2.deleteitem(ddlb_2.FindItem("大于等于", 2))ddlb_2.insertitem('小于

',3)ddlb_2.insertitem('大于',4)ddlb_2.insertitem('小于等于',5) ddlb_2.insertitem('大

于等于',6) em_1.TextColor = RGB(255,0,0) sle_1.visible = False em_1.SetMask(DateMask

!, 'mm/dd/yyyy')else ddlb_2.deleteitem(ddlb_2.FindItem("小于", 2)) ddlb_2.deleteitem

(ddlb_2.FindItem("大于", 2)) ddlb_2.deleteitem(ddlb_2.FindItem("小于等于", 2)) ddlb_

2.deleteitem(ddlb_2.FindItem("大于等于", 2)) ddlb_2.deleteitem(ddlb_2.FindItem("包含

", 2)) ddlb_2.deleteitem(ddlb_2.FindItem("不包含", 2))   ddlb_2.insertitem('包含',3)

ddlb_2.insertitem('不包含',4)sle_1.visible= Truesle_1.TextColor = RGB(255,0,0)end if 
不可见控件：cb_2 “转换”　事件（event）：Clicked　　Script  of  Clicked
file://将查询项转换为表info中字段名choose case ddlb_1.text case '资料名称' 

query_item='name' case '作者'  query_item='author' case '出版社'  query_item=

'publishing_house' case '出版日期'  query_item='publishing_date' case 'ISBN' 

query_item='ISBN' case '资料类别'  query_item='sort' case '购买日期'  query_item=

'buy_date' case '保管人'  query_item='keeper' case '备注'  query_item='memo'end

choose//将操作符转换为中文显示choose case ddlb_2.text case '等于'  query_operator='='

case '包含'  query_operator='like' case '不等于'  query_operator='<>' case '不包含' 

query_operator='not like'   case '小于等于'  query_operator='<=' case '大于等于' 

query_operator='>=' case '小于'  query_operator='<' case '大于'  query_operator=

'>'end choose
控件：pb_1 “检索”　事件（event）：Clicked　　Script  of  Clicked
string rqdate dcb_2.TriggerEvent(clicked!)//将英文操作符转换为中文显示dw_1.setredraw

(true)old_sql = dw_1.getsqlselect()//得到原有数据窗口的SQL语句if ddlb_1.text='出版日

期' or ddlb_1.text='购买日期' then//查询项为日期类型 em_1.GetData(d)//取出输入的日期

数据   rq = String(d, "yyyy/mm/dd")//将输入的日期数据转换为字符型 choose case

query_operator//根据操作符的不同将新产生的WHERE条件与老的SQL语句拼接成新的SQL语句 

case '='   new_sql = old_sql + " where " + query_item &          + " "+query_operator

+ 'date' +'(' + "'" + rq + "'" +')'    case '<>'   new_sql = old_sql + " where " +

query_item &          + " "+query_operator + 'date' +'(' + "'" + rq + "'" +')' &     

 +' or '+query_item+' is null '  case '<='   new_sql = old_sql + " where " +

query_item &          + " "+query_operator + 'date' +'(' + "'" + rq + "'" +')'  case

'>='   new_sql = old_sql + " where " + query_item &          + " "+query_operator +

'date' +'(' + "'" + rq + "'" +')' end choose////查询项为字符型else   sle_1.text=

Righttrim(sle_1.text)//将当前输入内容右面的空格去掉   choose case query_operator//根

据操作符的不同将新产生的WHERE条件与老的SQL语句拼接成新的SQL语句    case '='    

new_sql = old_sql + " where " + query_item &          + " "+query_operator + "'" +

parent.sle_1.text + "'"      case '<>'     new_sql = old_sql + " where " + query_item

&       + " "+query_operator + "'" + parent.sle_1.text + "'"&    +' or '+query_item+'

is null ' case 'like'  new_sql = old_sql + " where " + query_item &       + " "+

query_operator + "'" +'%'+ parent.sle_1.text +'%'+ "'" case 'not like'  new_sql =

old_sql + " where " + query_item &       + " "+query_operator + "'" +'%'+ parent.

sle_1.text +'%'+ "'"&  + ' or '+query_item+' is null 'end choose//end if//对原有数据

窗口进行新的查询 if dw_1.setsqlselect(new_sql) = -1 then  beep(3)       messagebox("

警告", "检索失败",stopsign!) elsedw_1.settransobject(sqlca)       dw_1.retrieve()    

  dw_1.setsqlselect(old_sql) end if
5.3.2 组合查询（条件查询）模块的实现：

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