| public static JetMove ( JET_SESID sesid, JET_TABLEID tableid, JET_Move numRows, MoveGrbit grbit ) : void | ||
| sesid | JET_SESID | The session to use for the call. |
| tableid | JET_TABLEID | The cursor to position. |
| numRows | JET_Move | An offset which indicates how far to move the cursor. |
| grbit | MoveGrbit | Move options. |
| return | void | |
public IEnumerable <DBRow> GetIndexInfo(string tableName, string indexName)
{
IEnumerable <ColSpec> tableDef = GetIndexTableDef(tableName, indexName);
JET_INDEXLIST indexList;
Esent.JetGetIndexInfo(m_sesid, m_dbid, tableName, indexName, out indexList, JET_IdxInfo.List);
var columnsByName = new Dictionary <string, int>();
int i = 0;
foreach (ColSpec column in tableDef)
{
columnsByName.Add(column.Name, i++);
}
Esent.JetMove(m_sesid, indexList.tableid, JET_Move.First, MoveGrbit.None);
i = 0;
do
{
var row = new List <object>();
foreach (ColSpec column in tableDef)
{
row.Add(column.Retriever(m_sesid, indexList.tableid, column.ColumnId));
}
yield return(new DBRow(columnsByName, row, i++));
}while (Esent.TryMoveNext(m_sesid, indexList.tableid));
Esent.JetCloseTable(m_sesid, indexList.tableid);
}
/// <summary>
/// Create an array of IndexSegment objects from the data in the current JET_INDEXLIST entry.
/// </summary>
/// <param name="sesid">The session to use.</param>
/// <param name="indexlist">The indexlist to take the data from.</param>
/// <returns>An array of IndexSegment objects containing the information for the current index.</returns>
private static IndexSegment[] GetIndexSegmentsFromIndexlist(JET_SESID sesid, JET_INDEXLIST indexlist)
{
var numSegments = (int)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidcColumn);
Debug.Assert(numSegments > 0, "Index has zero index segments");
var segments = new IndexSegment[numSegments];
for (int i = 0; i < numSegments; ++i)
{
string columnName = Api.RetrieveColumnAsString(
sesid,
indexlist.tableid,
indexlist.columnidcolumnname,
NativeMethods.Encoding,
RetrieveColumnGrbit.None);
columnName = StringCache.TryToIntern(columnName);
var coltyp = (JET_coltyp)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidcoltyp);
var grbit =
(IndexKeyGrbit)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidgrbitColumn);
bool isAscending = IndexKeyGrbit.Ascending == grbit;
var cp = (JET_CP)Api.RetrieveColumnAsInt16(sesid, indexlist.tableid, indexlist.columnidCp);
bool isASCII = JET_CP.ASCII == cp;
segments[i] = new IndexSegment(columnName, coltyp, isAscending, isASCII);
if (i < numSegments - 1)
{
Api.JetMove(sesid, indexlist.tableid, JET_Move.Next, MoveGrbit.None);
}
}
return(segments);
}
public IEnumerable <List <object> > GetRows(string tableName, string indexName = null, int startRow = 0, int rowCount = -1)
{
if (!m_tableDefs.ContainsKey(tableName))
{
LoadTableDef(tableName);
}
using (var table = new Table(m_sesid, m_dbid, tableName, OpenTableGrbit.ReadOnly)) {
var colspec = new List <KeyValuePair <string, Type> >();
try {
Esent.JetSetCurrentIndex2(m_sesid, table, indexName, SetCurrentIndexGrbit.MoveFirst);
if (startRow != 0)
{
Esent.JetMove(m_sesid, table, startRow, MoveGrbit.None);
}
}
catch (EsentNoCurrentRecordException) {
// Return an empty set.
yield break;
}
int rowNumber = 0;
do
{
var values = new List <object>();
object value = null;
foreach (var column in m_tableDefs[tableName])
{
try {
value = column.Retriever(m_sesid, table, column.ColumnId);
}
catch (Microsoft.Isam.Esent.Interop.EsentNoCurrentRecordException) {
// If we get this on row 0, it means there are no rows.
if (rowNumber == 0)
{
yield break;
}
else
{
throw;
}
}
values.Add(value);
}
yield return(values);
rowNumber++;
if (rowNumber == rowCount)
{
yield break;
}
}while (Esent.TryMoveNext(m_sesid, table));
}
} // GetRows
/// <summary>
/// Create an array of IndexSegment objects from the data in the current JET_INDEXLIST entry.
/// </summary>
/// <param name="sesid">The session to use.</param>
/// <param name="indexlist">The indexlist to take the data from.</param>
/// <returns>An array of IndexSegment objects containing the information for the current index.</returns>
private static IndexSegment[] GetIndexSegmentsFromIndexlist(JET_SESID sesid, JET_INDEXLIST indexlist)
{
var numSegments = (int)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidcColumn);
Debug.Assert(numSegments > 0, "Index has zero index segments");
// If we use the wide API (Vista+), then the temp table will be in UTF-16.
Encoding encodingOfTextColumns = EsentVersion.SupportsVistaFeatures ? Encoding.Unicode : LibraryHelpers.EncodingASCII;
var segments = new IndexSegment[numSegments];
for (int i = 0; i < numSegments; ++i)
{
string columnName = Api.RetrieveColumnAsString(
sesid,
indexlist.tableid,
indexlist.columnidcolumnname,
encodingOfTextColumns,
RetrieveColumnGrbit.None);
columnName = StringCache.TryToIntern(columnName);
var coltyp = (JET_coltyp)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidcoltyp);
var grbit =
(IndexKeyGrbit)Api.RetrieveColumnAsInt32(sesid, indexlist.tableid, indexlist.columnidgrbitColumn);
bool isAscending = IndexKeyGrbit.Ascending == grbit;
var cp = (JET_CP)Api.RetrieveColumnAsInt16(sesid, indexlist.tableid, indexlist.columnidCp);
bool isASCII = JET_CP.ASCII == cp;
segments[i] = new IndexSegment(columnName, coltyp, isAscending, isASCII);
if (i < numSegments - 1)
{
Api.JetMove(sesid, indexlist.tableid, JET_Move.Next, MoveGrbit.None);
}
}
return(segments);
}
