Question

I’m developing an android app of a library ,divide books into categories containing books,
implemented categories as sqlite tables and books as records ,i need to make _id of a book unique
through whole library ,
i tried this
category 1 _id 1 to 1000
category 2 _id 1001 to 2000
category 3 _id 2001 to 3000
but this limits each category to 1000 item
any solutions???

Answer 1

This is a sample from the DB Adapter I have implemented in my app. It uses the UNIQUE constraint to make sure duplicates are not allowed. Perhaps it could help.

String newTypesTableQueryString = "create table " +
TABLE_ONE +
" (" +
TABLE_TYP_ID + " integer primary key autoincrement," +
TABLE_TYP_TYPE + " text," +
"UNIQUE " +
" (" +
TABLE_TYP_TYPE +
" )" +
");";
// execute the query string to the database.
db.execSQL(newTypesTableQueryString);