Class RDbColReadStream

class RDbColReadStream : public RReadStream;

Description

Allows any column value to be read as stream data.

Note that this is the only way to extract the contents of a Long column from a rowset.

Only one column in a rowset object can be opened for reading as a stream at a time, and while it is open no column in the same rowset object may be set using RDbColWriteStream.

Null columns result in a read stream with no data. Small numeric columns are maintained in memory as 32-bit values; hence reading a Uint8 column as a stream results in 4 bytes of stream data, not 1.

Derivation

• RReadStream - The read stream interface

• RDbColReadStream - Allows any column value to be read as stream data

Members

Defined in RDbColReadStream:
OpenL(), OpenLC()

Inherited from RReadStream:
Attach(), Close(), Detach(), Pop(), PushL(), ReadInt16L(), ReadInt32L(), ReadInt8L(), ReadL(), ReadReal32L(), ReadReal64L(), ReadUint16L(), ReadUint32L(), ReadUint8L(), Release(), Source()

Capability:

Security policy note:

For a secure shared database, the caller must satisfy the read access policy for the table.

IMPORT_C void OpenL(const RDbRowSet &aView, TDbColNo aCol);

Description

Opens the column with the specified ordinal in the specified current row in the rowset. The row must have previously been read into the rowset using RDbRowSet::GetL().

Parameters

const RDbRowSet &aView The rowset which has the row and column to be read. TDbColNo aCol The column ordinal of the column to be read

Capability:

Security policy note:

For a secure shared database, the caller must satisfy the read access policy for the table.

IMPORT_C void OpenLC(const RDbRowSet &aView, TDbColNo aCol);

Description

Opens the column with the specified ordinal in the specified current row in the rowset and puts a pointer to the column on the cleanup stack.

The row must have previously been read into the rowset using RDbRowSet::GetL().

Parameters

const RDbRowSet &aView The rowset which has the row and column to be read. TDbColNo aCol The column ordinal of the column to be read.