Changeset 13 for trunk/DbEngines/UEngineXML.pas

Timestamp:

Mar 17, 2015, 12:09:11 AM (9 years ago)

Author:

chronos

Message:

• Modified: Now records are loaded from SQL database using SQL query. The query is parsed also by XML database client to load records from XML file.
• Added: Packages Network and Synapse.

File:

• trunk/DbEngines/UEngineXML.pas (modified) (3 diffs)

trunk/DbEngines/UEngineXML.pas

@@ -7 +7 @@
 uses
   Classes, SysUtils, DOM, XMLRead, XMLWrite, UDatabase, UXMLUtils, FileUtil,
-  UHtmlClasses;
+  UHtmlClasses, USqlDatabase, SpecializedDictionary;
 
 type
@@ -29 +29 @@
     procedure LoadFromFile(FileName: string);
     procedure SaveToFile(FileName: string);
+    function GetNextPart(var Text: string): string;
   public
+    procedure Query(DbRows: TDbRows; Text: string); override;
     procedure Load; override;
     procedure Save; override;
@@ -280 +282 @@
 end;
 
+function TDatabaseXML.GetNextPart(var Text: string): string;
+begin
+  if Pos(' ', Text) > 0 then begin
+    Result := Trim(Copy(Text, 1, Pos(' ', Text) - 1));
+    Delete(Text, 1, Pos(' ', Text));
+  end else begin
+    Result := Text;
+    Text := '';
+  end;
+end;
+
+procedure TDatabaseXML.Query(DbRows: TDbRows; Text: string);
+var
+  Command: string;
+  Columns: string;
+  TableName: string;
+  Table: TTable;
+  NewRecord: TDictionaryStringString;
+  I: Integer;
+  F: Integer;
+begin
+  Command := GetNextPart(Text);
+  if Command = 'SELECT' then begin
+    Columns := GetNextPart(Text);
+    Command := GetNextPart(Text);
+    if Command = 'FROM' then begin
+      TableName := GetNextPart(Text);
+    end;
+    Table := Database.Tables.SearchByName(TableName);
+    if Assigned(Table) then begin
+      DbRows.Count := 0;
+      if Columns = '*' then begin
+        for I := 0 to Table.Records.Count - 1 do begin
+          NewRecord := TDictionaryStringString.Create;
+          for F := 0 to Table.Fields.Count - 1 do
+            NewRecord.Add(TField(Table.Fields[F]).Name, TValue(TRecord(Table.Records[I]).Values[I]).GetString);
+          DbRows.Add(NewRecord);
+        end;
+      end else
+      if Columns = 'COUNT(*)' then begin
+        NewRecord := TDictionaryStringString.Create;
+        NewRecord.Add('COUNT(*)', IntToStr(Table.Records.Count));
+        DbRows.Add(NewRecord);
+      end else raise Exception.Create('Unsupported columns ' + Columns + ' specification');
+    end else raise Exception.Create('Table ' + TableName + ' not found.');
+  end else raise Exception.Create('Unsupported SQL command ' + Command);
+end;
+
 procedure TDatabaseXML.Load;
 begin