I need a code example. I'd like to see how we can enumerate columns names in table. (It's essential for me to use esent.dll/esent.lib and C language)
I tried to use attached code (found a guide but it doesn't work as I expect).
JET_COLUMNLIST column_info;
JET_RETRIEVECOLUMN j_rc[4];
err = JetGetTableColumnInfo(sessionID, curr_table.tableID, NULL, &column_info, sizeof(JET_COLUMNLIST), JET_ColInfoList);
j_rc[0].columnid = column_info.columnidcolumnname;
j_rc[0].cbData = sizeof(char)*JET_cbNameMost;
j_rc[0].itagSequence = 1;
j_rc[0].grbit = 0;
char buf[JET_cbNameMost] = { 0 };
j_rc[0].pvData = buf;
printf("\nRetrieving columns information:\n");
printf("Row\tId\tType\tName:\n");
unsigned long columns_qnt = 0;
for (err = JetMove(sessionID, curr_table.tableID, JET_MoveFirst, 0);
JET_errSuccess == err;
err = JetMove(sessionID, curr_table.tableID, JET_MoveNext, 0))
{
err = JetRetrieveColumns(sessionID, curr_table.tableID, j_rc, 4);
columns_qnt++;
printf("%u\t%s\n", columns_qnt, buf);
memset(buf, 0, JET_cbNameMost);
}
Please show an example. If you know good guides for ESE C programming or just some resources with describing of how it works, please share it with me. (Despite I googled a lot, don't be shy to share obvious for you resourses)
Inside table "MSysObjects" (which exists in every ESE database as service table) are 2 interisting for us columns: "Type" and "Name".
Here we fill structure JET_RETRIEVECOLUMN to get this 2 columns by JetRetrieveColumns
We got them here. If type == 1 it means, that record we got is describing a table and if type == 2, then it's describing a column . (There are also other types) There is strict order, first you will get record with type 1 (table) then you will get records with type 2 that describes columns of that table (in that moment buf keeps column name), then you can get records with other types (except type == 1) that refers to that table. And finally you will get record with type 1, that means that next information we get is about another table.
Feel free to say that my english is awful and I wrote some junk, I'll try to explain in other way then:)