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fcl-db: oracle: adjust buffer for BLOBs, when reading CLOBs,NCLOBs. Bug #32377

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git-svn-id: trunk@37184 -
This commit is contained in:
lacak 2017-09-11 17:48:17 +00:00
parent 55a0fd5121
commit 950082f371
2 changed files with 29 additions and 10 deletions
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37
packages/fcl-db/src/sqldb/oracle/oracleconnection.pp
View File

@ -383,19 +383,24 @@ var
ConnectString : string;
TempServiceContext : POCISvcCtx;
IsConnected : boolean;
CharSetId: ub2;
begin
{$IfDef LinkDynamically}
InitialiseOCI;
{$EndIf}
inherited DoInternalConnect;
//todo: get rid of FUserMem, as it isn't used
//ToDo: get rid of FUserMem, as it isn't used
FUserMem := nil;
IsConnected := false;
try
case GetConnectionCharSet of
'utf8': CharSetId := 873;
else CharSetId := 0; // if it is 0, the NLS_LANG and NLS_NCHAR environment variables are used
end;
// Create environment handle
if OCIEnvCreate(FOciEnvironment,OCI_DEFAULT,nil,nil,nil,nil,0,FUserMem) <> OCI_SUCCESS then
if OCIEnvNlsCreate(FOciEnvironment,OCI_DEFAULT,nil,nil,nil,nil,0,FUserMem,CharSetId,CharSetId) <> OCI_SUCCESS then
DatabaseError(SErrEnvCreateFailed,self);
// Create error handle
if OciHandleAlloc(FOciEnvironment,FOciError,OCI_HTYPE_ERROR,0,FUserMem) <> OCI_SUCCESS then
@ -405,10 +410,10 @@ begin
DatabaseError(SErrHandleAllocFailed,self);
// Initialize server handle
if hostname='' then
connectstring := databasename
if HostName='' then
ConnectString := DatabaseName
else
connectstring := '//'+hostname+'/'+databasename;
ConnectString := '//'+HostName+'/'+DatabaseName;
if OCIServerAttach(FOciServer,FOciError,@(ConnectString[1]),Length(ConnectString),OCI_DEFAULT) <> OCI_SUCCESS then
HandleError();
@ -453,7 +458,7 @@ begin
if not IsConnected then
begin
if assigned(FOciServer) then
OCIHandleFree(FOciServer,OCI_HTYPE_SERVER);
OCIHandleFree(FOciServer,OCI_HTYPE_SERVER);
if assigned(FOciError) then
OCIHandleFree(FOciError,OCI_HTYPE_ERROR);
if assigned(FOciEnvironment) then
@ -1120,7 +1125,7 @@ end;
procedure TOracleConnection.LoadBlobIntoBuffer(FieldDef: TFieldDef; ABlobBuf: PBufBlobField; cursor: TSQLCursor; ATransaction: TSQLTransaction);
var LobLocator: pointer;
LobCharSetForm: ub1;
LobLength: ub4;
LobLength, LobSize: ub4;
begin
LobLocator := (cursor as TOracleCursor).FieldBuffers[FieldDef.FieldNo-1].Buffer;
//if OCILobLocatorIsInit(TOracleTrans(ATransaction.Handle).FOciSvcCtx, FOciError, LobLocator, @is_init) = OCI_ERROR then
@ -1130,10 +1135,24 @@ begin
HandleError;
if OCILobCharSetForm(FOciEnvironment, FOciError, LobLocator, @LobCharSetForm) = OCI_ERROR then
HandleError;
// Adjust initial buffer size (in bytes), while LobLength can be in characters
case LobCharSetForm of
0: ; // BLOB
SQLCS_IMPLICIT, // CLOB
SQLCS_NCHAR: // NCLOB
LobLength := LobLength*4;
end;
ReAllocMem(ABlobBuf^.BlobBuffer^.Buffer, LobLength);
ABlobBuf^.BlobBuffer^.Size := LobLength;
if (LobLength > 0) and (OciLobRead(TOracleTrans(ATransaction.Handle).FOciSvcCtx, FOciError, LobLocator, @LobLength, 1, ABlobBuf^.BlobBuffer^.Buffer, LobLength, nil, nil, 0, LobCharSetForm) = OCI_ERROR) then
LobSize := 0;
// For CLOBs and NCLOBs the total amount of data which should be readed is on input in characters, but on output is in bytes if client character set is varying-width
// The application must call OCILobRead() (in streamed mode) over and over again to read more pieces of the LOB until the OCI_NEED_DATA error code is not returned.
// If the LOB is a BLOB, the csid and csfrm parameters are ignored.
if (LobLength > 0) and (OciLobRead(TOracleTrans(ATransaction.Handle).FOciSvcCtx, FOciError, LobLocator, @LobSize, 1, ABlobBuf^.BlobBuffer^.Buffer, LobLength, nil, nil, 0, LobCharSetForm) = OCI_ERROR) then
HandleError;
// Shrink initial buffer if needed (we assume that LobSize is in bytes, what is true for CLOB,NCLOB if client character set is varying-width, but if client character set is fixed-width then it is in characters)
if LobSize <> LobLength then
ReAllocMem(ABlobBuf^.BlobBuffer^.Buffer, LobSize);
ABlobBuf^.BlobBuffer^.Size := LobSize;
end;
procedure TOracleConnection.FreeFldBuffers(cursor: TSQLCursor);

2
packages/fcl-db/src/sqldb/sqldb.pp
View File

@ -1403,7 +1403,7 @@ function TSQLConnection.GetConnectionCharSet: string;
begin
// default implementation returns user supplied FCharSet
// (can be overriden by descendants, which are able retrieve current connection charset using client API)
Result := FCharSet;
Result := LowerCase(FCharSet);
end;
function TSQLConnection.RowsAffected(cursor: TSQLCursor): TRowsCount;