The data structure is as follows: Create Table [TBTree] ([ID] [VARCHAR] (4) Collate not null, [Context] [NVARCHAR] (50) NULL, [PARENTID] [VARCHAR] (4) NULL, Constraint [PK_TBTREE] Primary Key Clustered ([ID]) on [primary]) ON [PRIMARY] The code is as follows:
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Procedure TFORM1.Readtree (TNode: Ttreenode; Fvalue: String);
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VAR
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i: integer;
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Flist: tstringlist;
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FLIST1: TSTRINGLIST;
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Str: string;
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Begin
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QRYTREE.CLOSE;
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Qrytree.sql.clear;
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QRYTREE.SQL.Add ('Select ParentID, ID, Context from TBTree');
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QRYTREE.SQL.Add ('where isnull (parentid,' '') = ');
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QRYTREE.SQL.ADD ('' '' fvalue '' ');
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QRYTREE.OPEN
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QRYTREE.FIRST;
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FList: = TSTRINGLIST.CREATE;
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FLIST1: = TSTRINGLIST.CREATE;
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While not qrytree.eof do
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Begin
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FList.Add (qrytree.fieldbyname ('context'). Asstring);
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Flist1.add (qrytree.fieldbyname ('id'). Asstring;
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QRYTREE.NEXT;
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END;
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For i: = 0 to flist.count-1 do
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Begin
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S: = flist1.strings [i];
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Str: = flist.strings [i];
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Snode: = TreeView1.Items.Addchild (TNode, Str);
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Readtree (SNODE, S);
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END;
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FList.Free;
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FLIST1.FREE;
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END;
