Oracle技术:解析delta得到sql语句的函数
{解析出sql语句} function TForm1.gensqls(AdoCon:TADOConnection; pdelta: OleVariant; const ptablename, pkeyfields: WideString): WideString;var
i, j: integer;
s1, s2: string;
Cmdstr: string;
FieldList, Keylist: TstringList;
Cdsupdate: TClientDataSet;
sqlstr: WideString;
ado: TADOQuery;
begin
if varisnull(pdelta) then
Exit;
Cdsupdate:=TClientDataSet.Create(nil);
Cdsupdate.data:=pdelta;
if not Cdsupdate.Active then
Cdsupdate.Open;
try
FieldList:=TstringList.Create;
Keylist:=TstringList.Create;
Keylist.Delimiter:=',';
Keylist.DelimitedText:=pkeyfields;
ado:=TADOQuery.Create(nil);
ado.Connection:=AdoCon;
ado.sql.Text:='select * from '+ptablename+' where 1=0';
ado.Open;
Oracle技术:解析delta得到sql语句的函数
</p> ado.GetFieldNames(FieldList);ado.Free;
for i:=1 to FieldList.Count do
if Cdsupdate.FindField(FieldList)nil then
Cdsupdate.FindField(FieldList).tag:=1;
FieldList.Free;
if Cdsupdate.RecordCount>0 then
begin
Cdsupdate.First;
s1:='';
s2:='';
while not Cdsupdate.Eof do
begin
Cmdstr:='';
case Cdsupdate.UpdateStatus of
usUnmodified: //年夜原数据行取得改削前提
begin
s2:='';
for j:=1 to Keylist.Count do
begin
if s2='' then
s2:=Keylist+'='+vartosql(Cdsupdate])
else
s2:=s2+' and '+Keylist+'='+vartosql(Cdsupdate]);
end;
end;
usModified:
begin
s1:='';
for i:=1 to Cdsupdate.FieldCount do
begin
if (not Cdsupdate.Fields.isNull)and(Cdsupdate.Fields.tag=1) then
begin
if s1='' then
s1:=Trim(Cdsupdate.Fields.FieldName)+' = '+vartosql(Cdsupdate.Fields.value)
else
s1:=s1+','+Trim(Cdsupdate.Fields.FieldName)+' = '+vartosql(Cdsupdate.Fields.value);
end;
end;
if s1'' then
begin
Cmdstr:=' update '+ptablename+' set '+s1+' where '+s2;
end;
end;
usInserted:
begin
s1:='';
s2:='';
for i:=1 to Cdsupdate.FieldCount do
if (not Cdsupdate.Fields.isNull)and(Cdsupdate.Fields.tag=1) then
begin
Oracle技术:解析delta得到sql语句的函数
</p> if s1='' thenbegin
s1:=Trim(Cdsupdate.Fields.FieldName);
s2:=vartosql(Cdsupdate.Fields.value);
end
else
begin
s1:=s1+','+Trim(Cdsupdate.Fields.FieldName);
s2:=s2+','+vartosql(Cdsupdate.Fields.value);
end;
end;
if s1'' then
begin
Cmdstr:=' Insert into '+ptablename+'('+s1+') values('+s2+')';
end;
end;
usDeleted:
begin
s2:='';
for j:=1 to Keylist.Count do
begin
if s2='' then
s2:=Keylist+'='+vartosql(Cdsupdate])
else
s2:=s2+' and '+Keylist+'='+vartosql(Cdsupdate]);
end;
Cmdstr:='Delete '+ptablename+' where '+s2;
end;
end;
if Cmdstr'' then
sqlstr:=sqlstr+Cmdstr+';'+chr(13)+chr(10);
Cdsupdate.Next;
end;
end;
finally
Cdsupdate.close;
Cdsupdate.Free();
end;
Result:=sqlstr;
end;
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