第5章數(shù)據(jù)查詢與功能實現(xiàn)

imgPrivateSubForm_Load()'MakeaDimlrAsNewlr.Field= 'Addthe云南州界prjSetmlyr.Renderer=mlyr.Symbol.Color=Map1.Layers.Add'Buildpolygonsym.SymbolType=sym.Style=sym.Color=EndSubPrivateSubMap1_MouseDown(ButtonAsInteger,ShiftAsInteger,xAsSingle,yAsDimptClickAsDimstrPicLocAsSetptClick=Map1.ToMapPoint(x,Setrecs=moPointInPolygon,"")Map1.TrackingLayer.Refresh'Ifnothingclickedon,thenbailIfrecs.Count=0ExitEnd'Gettheimagenameoutofthelayer'sstrPicLoc='LoadtheForm2.Picture1.Picture=LoadPicture(App.Path&"\img\"&strPicLoc)'OpenthepictureEndSubPrivateSubMap1_AfterTrackingLayerDraw(ByValhDCAsstdole.OLE_HANDLE)'ifapolyisselected,drawitinIfNotrecsIsNothingMap1.DrawShaperecs,EndEndSubPrivateSubMe.Top=Me.Left=Form1.Left+Form1.WidthEndSubPrivateSubForm_Unload(CancelAsSetPicture1.Picture=NothingEndSub5.2.2根據(jù)屬性查詢要

只有一個:ANSISQLWHERE"SELECT*FROMCITIESWHEREPOP2000>SetrecsSelected=aMa 言SQL(StructuredQueryLanguage)是用于這些查詢與更新命令一同構成SQL命令集合 SELECT–UPDATE–DELETE–INSERTINTO–引(鍵),指定表之間的 ,及在數(shù)據(jù)表之SQL中最重要的DDL語句是CREATETABLE–ALTERTABLE–DROPTABLE–CREATEINDEX–創(chuàng)建索引(檢索鍵DROPINDEX– REVOKE查詢字"POP1996>

源數(shù)據(jù)確定的字符。使用百分號(%)來表示多個字符(_)表示單個字符,比如要在一個圖層中查詢GBCODE字段內容是GBCODElikeSTATE_NAMElike '(四個下劃線ADO數(shù)據(jù)表及SDE矢量圖層,expression以SQL語句的WHERE從句被直接傳遞到數(shù)據(jù)源因而表達式應該符合數(shù)據(jù)源所使用的準則。在查詢ArcSDEforCoveragesSetrecsSelected yer.SearchExpression("SUB_REGION=查詢后編DoUntilrecs.EOF Combo3中，在Combo2中加入比較運算符;設置一個符

控件上重控件上重繪它？查詢結果記錄集賦給公變量recSelection;刷新圖并同 初相似的布其所有取值內PrivateSubMap1.Layers.AddWithDimfldLyrAsForEachfldLyrIn IffldLyr.Type20Then\多邊形類型(Shape字段）.AddItemEndNext.ListIndex=EndWith.AddItem.AddItem.AddItem.AddItem.AddItem.AddItem.ListIndex=0EndWithCall Setg_symSelection=NewWith .SymbolType=.Color=EndWithEndSubombo1.ListIndex)).Type=moStringThen strExp=Combo1.List(Combo1.ListIndex)&Combo2.List(Combo2.ListIndex)&"?"&Combo3.Text&“?" strExp=Combo1.List(Combo1.ListIndex)&Combo2.List(Combo2.ListIndex)&""&EndSetrecSelection=MM1RhIfindex>0ThenExitIfrecSelectionIsNothingThenExitSubIfNotrecSelection.EOFThen Map1.DrawShaperecSelection,EndSetrecSelection=PrivateSubMap1.Move60,60,Me.ScaleWidth-180,Me.ScaleHeightLabel1.MoveMap1.Left,Map1.Top+Map1.Height+Map1.Width/2,Combo1.MoveLabel1.Left,Label1.Top+Label1.Height+60,Map1.Width*0.4Combo2.MoveCombo1.Left+Combo1.Width+60,Combo1.Top,(Map1.Width*0.2)-60Combo3.MoveCombo2.Left+Combo2.Width+60,Combo1.Top,Map1.Width*0.4+h*Command1.MoveMap1.Width*3/8,Combo1.TopCombo1.Height+60,Map1