SetTableSchema
SetTableSchema changes the schema of a table.unsigned __int64 SetTableSchema ( unsigned int tableID, const CODBPP::Schema *schema = NULL, const unsigned int *fieldMapping = NULL );
Parameters
| tableID | the table ID defining the table's handle. |
| schema | pointer to a valid schema. |
| fieldMapping | An array of int values allowing this method to map field from there old schema
to the new - eg. fieldMapping[0] = 2, will move the value in the first field of
the old table into the third field of the new table. Sub fields are appended to
the end so that <fields><sub fields 1><sub fields 2> and so no.
|
Return Values
If the method succeeds, the return value is zero else see error codes for more details.Remarks
- If fieldMapping parameter is missing, than SetTableSchema will map the first fixed field to the first fixed field, the second fixed field to the second and so on, plus the first variable field to the first variable field and so on.
- SetTableSchema is not part of the transaction.
- When schema equals NULL SetTableSchema attempts a rebuild and/or upgrade for the table file to its current standard and this will also open the table.
Example Use
- C++
#include "ODBPP.h"
#define TABLE_ONE 1
int wmain(int argc, wchar_t* argv[])
{
unsigned __int64 error;
int length;
const char16_t *message;
CODBPP database;
CODBPP::Schema *schema;
if((error = database.OpenDatabase(u"YourDatabase")) == NO_ERROR
&& (error = database.BeginTransaction(CODBPP::EXCLUSIVE)) == NO_ERROR
&& (error = database.OpenTable(TABLE_ONE)) == NO_ERROR
&& (error = database.GetTableSchema(TABLE_ONE,NULL,&length)) == NO_ERROR){
schema = (CODBPP::Schema*) new BYTE[length];
if((error = database.GetTableSchema(TABLE_ONE,schema)) == NO_ERROR){
//removes the last index if there is one
if(schema.indexCount > 0){
schema.indexCount--;
error = database.SetTableSchema(TABLE_ONE,schema);
}
}
delete [] (LPBYTE)schema;
}
if(error && database.GetErrorMessage(&message) == NO_ERROR)
MessageBox(message);
database.EndTransaction();
return NO_ERROR;
}Also See
GetTableSchemaListen All
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