C Examples: DbiDoRestructure

Example 1: Change first field type to fldINT16 and save table as NEW_CUST PX table to dBASE table.

This example uses the following input:
fDbiDoRestructure1(hDb, hCur, "CUSTOMER.DB");

DBIResult fDbiDoRestructure1(hDBIDb hDb, hDBICur hXCur, char *TblName)

{

DBIResult rslt;

CRTblDesc TblDesc;

CURProps CurProps;

pFLDDesc fldDesc;

pCROpType OpType;

rslt = Chk(DbiGetCursorProps(hXCur, &CurProps));

fldDesc = (pFLDDesc)malloc(CurProps.iFields * sizeof(FLDDesc));

rslt = Chk(DbiGetFieldDescs(hXCur, fldDesc));

fldDesc[0].iFldType = fldINT16;

memset((void *) &TblDesc, 0, sizeof(CRTblDesc));

lstrcpy(TblDesc.szTblName, TblName);

lstrcpy(TblDesc.szTblType, szDBASE);

TblDesc.pfldDesc = fldDesc;

OpType = (pCROpType)malloc((CurProps.iFields + 1) * sizeof(CROpType));

memset(OpType, crNOOP, (CurProps.iFields + 1) * sizeof(CROpType));

OpType[CurProps.iFields] = crMODIFY;

TblDesc.pecrFldOp = OpType;

rslt = Chk(DbiDoRestructure(hDb, 1, &TblDesc, "NEW_CUST", NULL,

NULL, FALSE));

return rslt;

}

Example 2: Pack a Paradox table.

This example uses the following input:
fDbiDoRestructure2(hDb, "CUSTOMER");

DBIResult fDbiDoRestructure2(hDBIDb hDb, char *TblName)

{

DBIResult rslt;

CRTblDesc TblDesc;

memset((void *) &TblDesc, 0, sizeof(CRTblDesc));

lstrcpy(TblDesc.szTblName, TblName);

lstrcpy(TblDesc.szTblType, szPARADOX);

TblDesc.bPack = TRUE;

rslt = Chk(DbiDoRestructure(hDb, 1, &TblDesc, NULL, NULL,

NULL, FALSE));

if(rslt == DBIERR_NONE)

ShowMessage("Successful Pack");

return rslt;

}

Example 3: Add validity checks and referential integrity to a table.

This example uses the following input:
fDbiDoRestructure3(hDb, "CUSTOMER");

DBIResult fDbiDoRestructure3(hDBIDb hDb, char *TblName)

{

DBIResult rslt;

CRTblDesc TblDesc;

RINTDesc pRintDesc[] = {{1, "Order No", rintDEPENDENT, "orders.db",

rintCASCADE, rintRESTRICT, 1, {2}, {1}}};

VCHKDesc pVchkDesc[] = {{1, TRUE, TRUE, FALSE, FALSE, 1000.00,

NULL, NULL, NULL, lkupNONE, NULL},

// Setting the first field required with minimum value 1000.00

{2, TRUE, TRUE, FALSE, FALSE, NULL, NULL,

NULL, NULL, lkupNONE, NULL}};

// Setting second field required.

memset((void *) &TblDesc, 0, sizeof(CRTblDesc));

lstrcpy(TblDesc.szTblName, TblName);

lstrcpy(TblDesc.szTblType, szPARADOX);

TblDesc.pvchkDesc = pVchkDesc;

TblDesc.printDesc = pRintDesc;

rslt = Chk(DbiDoRestructure(hDb, 1, &TblDesc, NULL, NULL,

NULL, FALSE));

return rslt;

}

Example 4: Add a default value to an existing field in a Paradox table.

This example uses the following input:
fDbiDoRestructure4(hDb, "STOCK", 2, &DefValue);

DBIResult fDbiDoRestructure4(hDBIDb hTmpDb, pCHAR TblName, UINT16 Field, pVOID Value)

{

DBIResult rslt;

CRTblDesc TblDesc;

VCHKDesc VCHK;

CROpType Operation = crADD;

memset(&VCHK, 0, sizeof(VCHK));

VCHK.iFldNum = Field;

VCHK.bHasDefVal = TRUE;

memcpy(&VCHK.aDefVal, Value, sizeof(Value));

memset(&TblDesc, 0, sizeof(TblDesc));

strcpy(TblDesc.szTblName, TblName);

strcpy(TblDesc.szTblType, szPARADOX);

TblDesc.iValChkCount = 1;

TblDesc.pecrValChkOp = &Operation;

TblDesc.pvchkDesc = &VCHK;

rslt = Chk(DbiDoRestructure(hTmpDb, 1, &TblDesc, NULL, NULL, NULL, FALSE));

return rslt;

}

Example 5: Add a new field to a Paradox or dBASE table

This example uses the following input:
fDbiDoRestructure5(hDb, "STOCK.DB", NewFld, "Stock Add.DB");

Note:

A field descriptor must be setup prior to calling this function. You must fill in szName, iFLdType, iSubType (optional), iUnits1 (optional), iUnits2 (optional).

DBIResult fDbiDoRestructure5(hDBIDb hTmpDb, pCHAR TblName, FLDDesc FldDesc, pCHAR NewTblName)

{

DBIResult rslt;

CRTblDesc TblDesc;

pCROpType AddOp;

UINT16 i;

pFLDDesc pFldDesc;

hDBICur hCur;

CURProps Props;

// Get an existing cursor on the source table.

rslt = Chk(DbiGetCursorForTable(hTmpDb, TblName, NULL, &hCur));

if (rslt != DBIERR_NONE)

return rslt;

// Get the amount of fields in the source table.

rslt = Chk(DbiGetCursorProps(hCur, &Props));

if (rslt != DBIERR_NONE)

return rslt;

// Get the existing field descriptor.

pFldDesc = (pFLDDesc)malloc((Props.iFields + 1) * sizeof(FLDDesc));

rslt = Chk(DbiGetFieldDescs(hCur, pFldDesc));

if (rslt != DBIERR_NONE)

{

free(pFldDesc); return rslt;

}

// Close the source table so the restructure can occur.

rslt = Chk(DbiCloseCursor(&hCur));

if (rslt != DBIERR_NONE)

{

free(pFldDesc); return rslt;

}

// Move the new field descriptor to the end of the source field descriptor.

memcpy(&pFldDesc[Props.iFields], &FldDesc, sizeof(FLDDesc));

// Put a crADD at the same position ad the new field descriptor

AddOp = (pCROpType)malloc((Props.iFields + 1) * sizeof(CROpType));

memset(AddOp, crNOOP, (Props.iFields + 1) * sizeof(CROpType));

AddOp[Props.iFields] = crADD;

memset(&TblDesc, 0, sizeof(TblDesc));

strcpy(TblDesc.szTblName, TblName);

TblDesc.iFldCount = (UINT16)(Props.iFields + 1);

TblDesc.pecrFldOp = AddOp;

TblDesc.pfldDesc = pFldDesc;

// Resync the field numbers in order.

for (i = 0; i < Props.iFields; i++)

pFldDesc[i].iFldNum = (UINT16)(i + 1);

rslt = Chk(DbiDoRestructure(hTmpDb, 1, &TblDesc, NewTblName, NULL, NULL, FALSE));

free(AddOp);

free(pFldDesc);

return rslt;

}

Example 6: Remove a validity descriptor on the specified field.

This example uses the following input:
fDbiDoRestructure6(hDb, "STOCK", 3);

DBIResult fDbiDoRestructure6(hDBIDb hTmpDb, pCHAR TblName, UINT16 Field)

{

DBIResult rslt;

CRTblDesc TblDesc;

CROpType Operation = crDROP;

VCHKDesc VCHK;

memset(&VCHK, 0, sizeof(VCHK));

VCHK.iFldNum = Field;

memset(&TblDesc, 0, sizeof(TblDesc));

strcpy(TblDesc.szTblName, TblName);

strcpy(TblDesc.szTblType, szPARADOX);

TblDesc.iValChkCount = 1;

TblDesc.pecrValChkOp = &Operation;

TblDesc.pvchkDesc = &VCHK;

rslt = Chk(DbiDoRestructure(hTmpDb, 1, &TblDesc, NULL, NULL, NULL, FALSE));

return rslt;

}