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unit BDEClientDataSet;
interface
uses Windows, SysUtils, Variants, Classes, DB, DBCommon, Midas,
SqlTimSt, DBClient, DBLocal, Provider, DBTables;
type
{ TBDEQuery }
TBDEQuery = class(TQuery)
private
FKeyFields: string;
protected
function PSGetDefaultOrder: TIndexDef; override;
end;
{ TBDEClientDataSet }
TBDEClientDataSet = class(TCustomCachedDataSet)
private
FCommandText: string;
FCurrentCommand: string;
FDataSet: TBDEQuery;
FDatabase: TDataBase;
FLocalParams: TParams;
FStreamedActive: Boolean;
procedure CheckMasterSourceActive(MasterSource: TDataSource);
procedure SetDetailsActive(Value: Boolean);
function GetConnection: TDataBase;
function GetDataSet: TDataSet;
function GetMasterSource: TDataSource;
function GetMasterFields: string;
procedure SetConnection(Value: TDataBase);
procedure SetDataSource(Value: TDataSource);
procedure SetLocalParams;
procedure SetMasterFields(const Value: string);
procedure SetParamsFromSQL(const Value: string);
procedure SetSQL(const Value: string);
protected
function GetCommandText: String; override;
procedure Loaded; override;
procedure Notification(AComponent: TComponent; Operation: TOperation); override;
procedure SetActive(Value: Boolean); override;
procedure SetCommandText(Value: string); override;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure CloneCursor(Source: TCustomClientDataSet; Reset: Boolean;
KeepSettings: Boolean = False); override;
procedure GetFieldNames(List: TStrings); override;
function GetQuoteChar: String;
property DataSet: TDataSet read GetDataSet;
published
property Active;
property CommandText: string read GetCommandText write SetCommandText;
property DBConnection: TDataBase read GetConnection write SetConnection;
property MasterFields read GetMasterFields write SetMasterFields;
property MasterSource: TDataSource read GetMasterSource write SetDataSource;
end;
procedure Register;
implementation
uses BDEConst, MidConst;
type
{ TBDECDSParams }
TBDECDSParams = class(TParams)
private
FFieldName: TStrings;
protected
procedure ParseSelect(SQL: string);
public
constructor Create(Owner: TPersistent);
Destructor Destroy; override;
end;
constructor TBDECDSParams.Create(Owner: TPersistent);
begin
inherited;
FFieldName := TStringList.Create;
end;
destructor TBDECDSParams.Destroy;
begin
FreeAndNil(FFieldName);
inherited;
end;
procedure TBDECDSParams.ParseSelect(SQL: string);
const
SSelect = ''''select'''';
var
FWhereFound: Boolean;
Start: PChar;
FName, Value: string;
SQLToken, CurSection, LastToken: TSQLToken;
Params: Integer;
begin
if Pos('''' '''' + SSelect + '''' '''', LowerCase(string(PChar(SQL)+8))) > 1 then Exit; // can''''t parse sub queries
Start := PChar(ParseSQL(PChar(SQL), True));
CurSection := stUnknown;
LastToken := stUnknown;
FWhereFound := False;
Params := 0;
repeat
repeat
SQLToken := NextSQLToken(Start, FName, CurSection);
if SQLToken in [stWhere] then
begin
FWhereFound := True;
LastToken := stWhere;
end else if SQLToken in [stTableName] then
begin
{ Check for owner qualified table name }
if Start^ = ''''.'''' then
NextSQLToken(Start, FName, CurSection);
end else
if (SQLToken = stValue) and (LastToken = stWhere) then
SQLToken := stFieldName;
if SQLToken in SQLSections then CurSection := SQLToken;
until SQLToken in [stFieldName, stEnd];
if FWhereFound and (SQLToken in [stFieldName]) then
repeat
SQLToken := NextSQLToken(Start, Value, CurSection);
if SQLToken in SQLSections then CurSection := SQLToken;
until SQLToken in [stEnd,stValue,stIsNull,stIsNotNull,stFieldName];
if Value=''''?'''' then
begin
FFieldName.Add(FName);
Inc(Params);
end;
until (Params = Count) or (SQLToken in [stEnd]);
end;
{ TBDEQuery }
function TBDEQuery.PSGetDefaultOrder: TIndexDef;
begin
if FKeyFields = '''''''' then
Result := inherited PSGetDefaultOrder
else
begin // detail table default order
Result := TIndexDef.Create(nil);
Result.Options := [ixUnique]; // keyfield is unique
Result.Name := StringReplace(FKeyFields, '''';'''', ''''_'''', [rfReplaceAll]);
Result.Fields := FKeyFields;
end;
end;
{ TBDEClientDataSet }
constructor TBDEClientDataSet.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FDataSet := TBDEQuery.Create(nil);
FDataSet.Name := Self.Name + ''''DataSet1'''';
Provider.DataSet := FDataSet;
SqlDBType := typeBDE;
FLocalParams := TParams.Create;
end;
destructor TBDEClientDataSet.Destroy;
begin
FreeAndNil(FLocalParams);
FDataSet.Close;
FreeAndNil(FDataSet);
inherited Destroy;
end;
procedure TBDEClientDataSet.GetFieldNames(List: TStrings);
var
Opened: Boolean;
begin
Opened := (Active = False);
try
if Opened then
Open;
inherited GetFieldNames(List);
finally
if Opened then Close;
end;
end;
function TBDEClientDataSet.GetCommandText: string;
begin
Result := FCommandText;
end;
function TBDEClientDataSet.GetDataSet: TDataSet;
begin
Result := FDataSet as TDataSet;
end;
procedure TBDEClientDataSet.CheckMasterSourceActive(MasterSource: TDataSource);
begin
if Assigned(MasterSource) and Assigned(MasterSource.DataSet) then
if not MasterSource.DataSet.Active then
DatabaseError(SMasterNotOpen);
end;
procedure TBDEClientDataSet.SetParamsFromSQL(const Value: string);
var
DataSet: TQuery;
TableName, TempQuery, Q: string;
List: TBDECDSParams;
I: Integer;
Field: TField;
begin
TableName := GetTableNameFromSQL(Value);
if TableName <> '''''''' then
begin
TempQuery := Value;
List := TBDECDSParams.Create(Self);
try
List.ParseSelect(TempQuery);
List.AssignValues(Params);
for I := 0 to List.Count - 1 do
List[I].ParamType := ptInput;
DataSet := TQuery.Create(nil);
try
DataSet.DatabaseName := FDataSet.DatabaseName;
Q := GetQuoteChar;
DataSet.SQL.Add(''''select * from '''' + Q + TableName + Q + '''' where 0 = 1''''); { do not localize }
try
DataSet.Open;
for I := 0 to List.Count - 1 do
begin
if List.FFieldName.Count > I then
begin
try
Field := DataSet [1] [2] 下一页
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