JET_RETINFO Structure

Applies to: Windows | Windows Server

JET_RETINFO Structure

The JET_RETINFO structure contains optional input and output parameters for JetRetrieveColumn. A null pointer can be passed where a pointer to this structure would otherwise be passed. Passing a null pointer is the same as passing JET_RETINFO with cbStruct set to sizeof(JET_RETINFO), ibLongValue set to 0 (zero) and itagSequence set to 1.

    typedef struct {
      unsigned long cbStruct;
      unsigned long ibLongValue;
      unsigned long itagSequence;
      JET_COLUMNID columnidNextTagged;
    } JET_RETINFO;

Members

cbStruct

Must be set to the size of the JET_RETINFO structure, in bytes, and serves to confirm the presence of the following fields.

ibLongValue

The offset to the first byte to be retrieved from a column of type JET_coltypLongBinary, or JET_coltypLongText. Note that the amount of data retrieved from this offset is the lower of the size of the output buffer and the size of data in the actual value after this offset.

itagSequence

Describes the sequence number of value in a multi-valued column. Note that the array of values is one-based. The first value is sequence 1, not 0. If the record column has only one value then 1 should be passed as the itagSequence

With a column that can contain multiple values, it is only possible to use a sequence number larger than 1 in JetSetColumn and JetRetrieveColumn or 0 in JetSetColumn. In the current implementation of the engine, any column that was created with JET_bitColumnTagged can contain multiple values. Columns created with JET_bitColumnMultiValued differ from multi-valued tagged columns only in the way that they are indexed. See JET_INDEXCREATE for more information.

columnidNextTagged

Returns the columnid of the retrieved tagged, multi-valued or sparse, column when all tagged columns are retrieved by passing 0 as the columnid to JetRetrieveColumn.

Requirements

See Also

JET_COLTYP
JET_COLUMNID
JET_RETINFO
JetRetrieveColumn