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A c-treeDB table handle or object can be attached and detached to an already open data file. Applications may need to open a table using c-tree ISAM and low level functions and then attach the table to a c-treeDB table handle to take advantage of full c-treeDB functionality.
CTTable::Attach() attaches a c-tree Plus ISAM datno object to a c-treeDB table handle. This function is useful if you have opened a data or index file using one of c- tree’s ISAM open functions and need to attach it to a table handle to use some of the advanced c-treeDB features such as alter table or the record handler.
AttachXtd() attaches a c-tree Plus ISAM datno object to a c-treeDB table handle. This function is useful if you have opened a data and index file using one of c-tree’s ISAM open functions and need to attach it to a table handle to use some of the advanced c-treeDB features such as alter table or the record handler. This extended version allows the user to specify the DODA and IFIL for the table, enabling tables without DODA and/or IFIL to be attached to c-treeDB.
Detach() detaches a c-treeDB table handle from a c-tree data and index files. The table is not closed but the c-treeDB table handle resources are released and the handle re-initialized.
Example
/* DODA */
static DATOBJ doda[] =
{
{"f1", (pTEXT)0, CT_INT4, 4},
{"f2", (pTEXT)4, CT_FSTRING, 10}
};
/* IFIL */
static ISEG iseg = {0, 4, 12};
static IIDX iidx = {4, 0, 0, 0, 0, 1, &iseg, "i311x1", NULL, NULL, NULL};
static IFIL ifil = {"test310", -1, 14, 0, 0, 1, 0, 0, &iidx, "f1", "f2", 0};
CTHANDLE hSession = ctdbAllocSession(CTSESSION_CTREE);
CTHANDLE hTable = ctdbAllocTable(hSession);
CTHANDLE hRecord = ctdbAllocRecord(hTable);
NINT datno, count = 0;
/* logon to c-tree */
ctdbLogon(hSession, SERVER, USER, PASSWD);
/* open the file using c-tree ISAM */
datno = (NINT)OPNRFILX((COUNT) -1, "test309.dat", (COUNT)0, NULL);
/* attach to table */
ctdbAttachTableXtd(hTable, datno, doda, &ifil);
/* read the records */
if (ctdbFirstRecord(hRecord) == CTDBRET_OK)
do
{
count++;
}
while (ctdbNextRecord(hRecord) == CTDBRET_OK);
/* cleanup */
ctdbDetachtable(hTable);
ctdbFreeRecord(hRecord);
ctdbFreeTable(hTable);
ctdbLogout(hSession);
ctdbFreeSession(hSession);
CTDBRET ctdbDetachTable(CTHANDLE Handle);
void CTTable::Detach();
