Add, delete, change, and check the SQLite database using the methods recommended by the API in Android

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 {//Gets the database object to manipulate private personsqliteopenhelper helper;/** * Completion of helper initialization in the construction method * * @param context */public persondaoforandroid (context context) {helper = new Personsqliteopenhelper ( context);} /** * Add Data * * @param name name * @param number Phone * @return returns the row ID of the newly inserted row, or-1 indicates an error */public long Add (string name, String n umber) {//Gets the connection object of the database Sqlitedatabase db = Helper.getwritabledatabase ();//The following is the API recommended notation contentvalues values = new Contentvalues (); Values.put ("name", name), Values.put ("number", number),///Target data table//returns the row ID of the newly inserted row, or-1 indicates an error occurred long id = Db.insert ("person", null, values);//Close database connection Db.close (); return ID;}    /** * Query data by user name * * @param name *        Query condition * @return Query result */public person Findbyname (String name) {//Get database connection Sqlitedatabase db = Helper.getreadabledatab ASE ();//Target data table name | Specifies the returned data field if NULL is set to return all data fields | Conditional statement, excluding where keyword | The argument list for the condition | Grouped statement |having QUERY statement | ordered statement, If you do not set the default cursor cursor = db.query ("person", NULL, "Name=?", new string[] {name}, NULL, NULL, NULL);//Declare result object person pers On = null;//to determine if there is a result return if (Cursor.movetonext ()) {/////Cursor.getcolumnindex ("id") of the field data of a single row of data in the data set; Gets the subscript for the specified field// Cursor.getint (index), or GetString (index); Is the data that gets the specified subscript index to int type; int id = cursor.getint (cursor.getcolumnindex ("id")) ; String named = cursor.getstring (Cursor.getcolumnindex ("name")); String number = cursor.getstring (Cursor.getcolumnindex ("number"));//Instantiate query result data Object person = new person (ID, named, number);} Close the database connection, release the Resource Db.close ();//Return the data result object return person; /** * Update a data according to name * * @param name * with new conditions * @param newnumber * NEW data * @return rows affected rows */public I NT Update (string name, String newnumber) {Sqlitedatabase db = Helper.getwritaBledatabase (); Contentvalues values = new Contentvalues () values.put ("number", newnumber);//Target data table | The data to be updated | Update CONDITION statement | Update condition argument list int rows = Db.update ("person", Values, "Name=", new string[] {name});d b.close (); return rows;}  /** * Delete Data according to the specified name * * @param name * Delete condition * @return rows affected rows */public int Delete (String name) {Sqlitedatabase db = Helper.getwritabledatabase ();//target database table name | Conditional statement | condition parameter int rows = db.delete ("Person", "Name=?", new string[] {name});d b . Close (); return rows;} /** * Query All operations * * @return The result set of the query */public list<person> findAll () {Sqlitedatabase db = Helper.getreadabledatabase (); cursor cursor = db.query ("person", NULL, NULL, NULL, NULL, NULL, NULL);//Declare result set//Initialize result set list<person> persons = new A Rraylist<person> ();//Determine if there is a result return while (Cursor.movetonext ()) {//Declare result object person man = null;//take out data from a single row of data in the dataset/ /Cursor.getcolumnindex ("id"), gets the subscript//Cursor.getint (index) of the specified field, or GetString (index); Is the data that gets the specified subscript index to int type; int id = Cursor.getint (Cursor.getcolumnindex ("id")); String named = cursor.getstring (Cursor.getcolumnindex ("name")); String number = cursor.getstring (Cursor.getcolumnindex ("number"));//instantiation of query result data Object person = new person (ID, named, number) ;//Add Data Persons.add (person) to the result set;} Close the connection, release the Resource Db.close ();//Put back the result set return persons;}}

other code see another blog Android implementation of the SQLite database to increase, delete, change, check the operation