Use the API recommended method in Android to add, delete, modify, and query SQLite Databases

Package com. examp. use_SQLite.dao; import java. util. arrayList; import java. util. list; import android. content. contentValues; import android. content. context; import android. database. cursor; import android. database. sqlite. SQLiteDatabase; import com. examp. use_SQLite.PersonSQLiteOpenHelper; import com. examp. use_SQLite.domain.Person; public class PersonDaoForAndroid {// obtain the database object to be operated private PersonSQLiteOpenHelper he Lper;/*** initialize helper in the constructor *** @ param context */public PersonDaoForAndroid (Context context) {helper = new PersonSQLiteOpenHelper (context );} /***** add data ** @ param name * @ param number * @ return returns the row ID of the newly inserted row, or-1 indicates an error */public long add (String name, String number) {// obtain the database connection object SQLiteDatabase db = helper. getWritableDatabase (); // The following is the API recommendation method ContentValues values = new ContentValues (); values. put ("Name", name); values. put ("number", number); // target data table // return the row ID of the newly inserted row, or-1 indicates that an error occurs long id = db. insert ("person", null, values); // close the database connection in time. close (); return id;}/*** query data by user name ** @ param name * query condition * @ return query result */public Person findByName (String name) {// obtain the database connection SQLiteDatabase db = helper. getReadableDatabase (); // target data table name | specify the returned data field. If null is set, all data fields are returned. | Condition Statement, excluding the where keyword | condition parameter list | grouping statement | having query statement | sort Language If not set, the default Cursor cursor = db. query ("person", null, "name =? ", New String [] {name}, null); // declare the result object Person person = null; // determine whether results are returned if (cursor. moveToNext () {// retrieve the data of the fields of a single row of data in the dataset // cursor. getColumnIndex ("id"); returns the subscript of the specified field // cursor. getInt (index); or getString (index); is used to obtain the data index of the specified underlying object as the int type; int id = cursor. getInt (cursor. getColumnIndex ("id"); String named = cursor. getString (cursor. getColumnIndex ("name"); String number = cursor. getString (cursor. getColum NIndex ("number"); // instantiate the query result data object person = new Person (id, named, number);} // close the database connection and release the resource database. close (); // return data result object return person ;} /*** update a piece of data based on name ** @ param name * and new condition * @ param newnumber * New Data * @ return rows affected rows */public int update (String name, string newnumber) {SQLiteDatabase db = helper. getWritableDatabase (); ContentValues values = new ContentValues (); values. put ("number", newnumber); // target data table | New data | update Condition Statement | update condition parameter list int rows = db. update ("person", values, "name =? ", New String [] {name}); db. close (); return rows ;} /*** delete data based on the specified name ** @ param name * Deletion condition * @ return rows affected rows */public int delete (String name) {SQLiteDatabase db = helper. getWritableDatabase (); // target database table name | Condition Statement | condition parameter int rows = db. delete ("person", "name =? ", New String [] {name}); db. close (); return rows;}/*** query all operations ** @ return query result set */public List
 
  
FindAll () {SQLiteDatabase db = helper. getReadableDatabase (); Cursor cursor = db. query ("person", null, null); // declare the result set // initialize the result set List
  
   
Persons = new ArrayList
   
    
(); // Determine whether results are returned while (cursor. moveToNext () {// declare the result object Person person = null; // retrieve the data of individual data fields in the dataset. // cursor. getColumnIndex ("id"); returns the subscript of the specified field // cursor. getInt (index); or getString (index); is used to obtain the data index of the specified underlying object as the int type; int id = cursor. getInt (cursor. getColumnIndex ("id"); String named = cursor. getString (cursor. getColumnIndex ("name"); String number = cursor. getString (cursor. getColumnIndex ("number"); // instantiate the query result data object person = new Person (id, named, number); // Add data persons to the result set. add (person) ;}// close the connection and release the resource database. close (); // return the result set return persons ;}}
   
  
 

For other code, see the Android blog to add, delete, modify, and query SQLite databases.