core33Example_main.c
Basic tutorial in C where a database with a unique key is created, a row is inserted and then a row is retrieved and displayed. This example needs a compiled schema, core33Example.sdl.
/*
* UNIQUE KEY
* ----------
*
* This document describes the process to create a simple database
* containing a unique key, insert records, and read data through the
* key.
*
* For a full description of RDM keys, see Database Design in the
* Users Guide.
*
* This example contains a single record type with a single field
* which is designated as a unique key. This means that every record
* of type info that is successfully inserted into the database will
* have a unique value. If an insertion is attempted with a key field
* value that already exists in the database, the insertion is
* rejected and an error code is returned from the d_fillnew function.
*/
#include "rdm.h"
#include "rdmapi.h"
#include "rdmtfsapi.h"
#include "core33Example_structs.h"
#include "core33Example_cat.h"
#include "rdmstartupapi.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
static const char szData[][34] = {
"John", "James", "Duncan",
"Bill", "John", /* Inserting this should fail, referential integrity rules
violated. */
"Paul", "David"};
int32_t main_core33ExampleTutorial (int32_t argc, const char *const *argv)
{
RDM_RETCODE rc;
uint32_t ii;
INFO sInfo;
RDM_TFS tfs;
RDM_TABLE_ID tables[] = {TABLE_INFO};
RDM_UNREF (argc);
RDM_UNREF (argv);
/* Allocate a TFS Handle */
rc = rdm_rdmAllocTFS (&tfs);
{
rc = rdm_tfsInitialize (tfs);
if (rc == sOKAY)
{
RDM_DB db;
/* Allocate a database hande */
rc = rdm_tfsAllocDatabase (tfs, &db);
if (rc == sOKAY)
{
/* Override default DURABLE setting to CONSISTENT */
}
if (rc == sOKAY)
{
rc = rdm_dbSetCatalog (db, core33Example_cat);
if (rc == sOKAY)
{
/* Open the database. */
if (rc != sOKAY)
{
printf ("Can't open the core33Example database.");
}
}
if (rc == sOKAY)
{
/* Start an update transaction and lock the table */
rc = rdm_dbStartUpdate (
db, tables, RDM_LEN (tables), NULL, 0, NULL);
}
if (rc == sOKAY)
{
/* Remove all of the rows from the database */
rc = rdm_dbDeleteAllRowsFromDatabase (db);
if (rc == sOKAY)
{
/* Commit a transaction */
rc = rdm_dbEnd (db);
}
else
{
/* Abort the transaction */
rdm_dbEndRollback (db);
}
}
if (rc == sOKAY)
{
/* Start an update transaction and lock the table */
rc = rdm_dbStartUpdate (
db, tables, RDM_LEN (tables), NULL, 0, NULL);
}
if (rc == sOKAY)
{
/* Add rows to the info table */
{
strcpy (sInfo.mychar, szData[ii]);
sInfo._mychar_has_value = RDM_COL_HAS_VALUE;
rc = rdm_dbInsertRow (
db, TABLE_INFO, &sInfo, sizeof (sInfo), NULL);
{
printf (
"%s is a duplicate record.\n", sInfo.mychar);
rc = sOKAY; /* This was expected, re-set error code.
*/
}
}
}
if (rc == sOKAY)
{
/* Start a read transaction and lock the table */
}
if (rc == sOKAY)
{
RDM_CURSOR cursor = NULL;
INFO_MYCHAR_KEY keyVal = {"", RDM_COL_HAS_VALUE};
/* Get a key cursor positioned to the first row with the
* request key value */
strcpy (keyVal.mychar, szData[3]);
rc = rdm_dbGetRowsByKeyAtKey (
db, KEY_INFO_MYCHAR, &keyVal, sizeof (keyVal), &cursor);
if (rc == sOKAY)
{
rc = rdm_cursorReadRow (
cursor, &sInfo, sizeof (sInfo), NULL);
if (rc == sOKAY)
{
printf (
"Row found doing a key lookup: %s\n",
sInfo.mychar);
}
/* Do a closest key match lookup, and return the rest in
* key order. */
if (rc == sOKAY)
{
INFO_MYCHAR_KEY keyVal = {"Jim", RDM_COL_HAS_VALUE};
rc = rdm_cursorMoveToKey (
cursor, KEY_INFO_MYCHAR, &keyVal,
sizeof (keyVal));
/* If we didn't get en exact match move to the next
* close key value */
{
rc = rdm_cursorMoveToNext (cursor);
}
while (rc == sOKAY)
{
rc = rdm_cursorReadRow (
cursor, &sInfo, sizeof (sInfo), NULL);
if (rc == sOKAY)
{
printf (
"Row found doing a key scan lookup: "
"%s\n",
sInfo.mychar);
rc = rdm_cursorMoveToNext (cursor);
}
}
/* We expect to break out of the loop with a
* sENDOFCURSOR return code */
{
rc = sOKAY;
}
}
/* Free the cursor allocated by rdm_dbGetRowsByKeyAtKey
*/
rdm_cursorFree (cursor);
}
rdm_dbEnd (db);
}
rdm_dbFree (db);
}
}
rdm_tfsFree (tfs);
}
if (rc != sOKAY)
{
printf (
"There was an error in this Tutorial (%s - %s)\n",
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
RDM_STARTUP_EXAMPLE (core33ExampleTutorial)
const char * rdm_retcodeGetName(RDM_RETCODE retcode)
Get the mnemonic name for an error or status code.
Header for the native RDM Runtime API.
Header for the RDM Core API.
RDM_RETCODE rdm_dbDeleteAllRowsFromDatabase(RDM_DB db)
Remove all rows from a database.
RDM_RETCODE rdm_dbStartRead(RDM_DB db, const RDM_TABLE_ID *tableIds, uint32_t numTableIds, RDM_TRANS *pTrans)
Get read locks.
RDM_RETCODE rdm_cursorReadRow(RDM_CURSOR cursor, void *colValues, size_t bytesIn, size_t *bytesOut)
Read all columns from a row.
RDM_RETCODE rdm_dbSetCatalog(RDM_DB db, const char *catalog)
Associate a catalog with an allocated database.
RDM_RETCODE rdm_dbOpen(RDM_DB db, const char *dbNameSpec, RDM_OPEN_MODE mode)
Open an existing RDM database using the specified database handle.
RDM_RETCODE rdm_dbGetRowsByKeyAtKey(RDM_DB db, RDM_KEY_ID keyId, const void *keyValue, size_t len, RDM_CURSOR *pCursor)
Associate an RDM_CURSOR with a row set that is ordered by key value and is initially positioned at th...
RDM_RETCODE rdm_tfsAllocDatabase(RDM_TFS tfs, RDM_DB *pDb)
Allocate memory for a new RDM db.
Header for the Transactional File Server (TFS) API.
const char * rdm_retcodeGetDescription(RDM_RETCODE retcode)
Invoke RDM error handler.
RDM_RETCODE rdm_dbEndRollback(RDM_DB db)
End and rollback a transactional operation.
RDM_RETCODE rdm_dbInsertRow(RDM_DB db, RDM_TABLE_ID tableId, const void *colValues, size_t bytesIn, RDM_CURSOR *pCursor)
Insert a new row into a table at the specified rowId.
RDM_RETCODE rdm_dbStartUpdate(RDM_DB db, const RDM_TABLE_ID *writeTableIds, uint32_t numWriteTableIds, const RDM_TABLE_ID *readTableIds, uint32_t numReadTableIds, RDM_TRANS *pTrans)
Get write locks.
Internal RDM Startup API used by startup macros.