Learning SQLite in Android

Added, deleted, and queried data. Bind the spinner control and the listview control to click the delete list option.

 

Package COM. example. splite; 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 android. database. SQLite. sqlitedatabase. cursorfactory; import android. database. SQLite. sqliteopenhelper; import android. util. log; public class dbhelpe extends sqliteopenhelper {Private Static final int database_version = 1; Private Static final string database_name = "test"; Private Static final string table_labels = "labels "; private Static final string key_id = "ID"; Private Static final string key_name = "name"; sqlitedatabase dB; Public dbhelpe (context) {super (context, database_name, null, database_version); // todo auto-generated constructor stub} @ override public void oncreate (sqlitedatabase dB) {// todo auto-generated method stub string SQL = "CREATE TABLE" + table_labels + "(" + key_id + "integer primary key," + key_name + "text )"; db.exe csql (SQL) ;}@ override public void onupgrade (sqlitedatabase dB, int oldversion, int newversion) {// todo auto-generated method stub db.exe csql ("Drop table if exists" + table_labels); oncreate (db) ;}// add public void insertlabel (string label) {DB = This. getwritabledatabase (); contentvalues values = new contentvalues (); values. put (key_name, label); dB. insert (table_labels, null, values); dB. close (); // closing database connection} // search for public list <string> getalllabels () {list <string> labels = new arraylist <string> (); string selectquery = "select * from" + table_labels; sqlitedatabase DB = This. getreadabledatabase (); cursor = dB. rawquery (selectquery, null); If (cursor. movetofirst () {do {labels. add (cursor. getstring (1);} while (cursor. movetonext ();} cursor. close (); Return labels;} // Delete public void Delete (string name) {If (DB = NULL) dB = This. getreadabledatabase (); string SQL = "delete from labels where name = '" + name + "'"; db.exe csql (SQL );}}

There is a method in the main class, that is, when you click the add data button, the text input box of the system is automatically hidden to implement code

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);                imm.hideSoftInputFromWindow(edittext.getWindowToken(), 0);

 

Package COM. example. splite; import Java. util. list; import android. OS. bundle; import android. app. activity; import android. content. context; import android. database. cursor; import android. util. log; import android. view. menu; import android. view. view; import android. view. view. onclicklistener; import android. view. inputmethod. inputmethodmanager; import android. widget. adapterview; import android. widget. adapterview. oni Temclicklistener; import android. widget. arrayadapter; import android. widget. button; import android. widget. edittext; import android. widget. listview; import android. widget. scrollview; import android. widget. spinner; import android. widget. toast; public class mainactivity extends activity implements onitemclicklistener {spinner; edittext; button; scrollview SCR; listview list; cursor m Cursor; @ override protected void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. activity_main); List = (listview) findviewbyid (R. id. listview); button = (button) findviewbyid (R. id. btn_add); edittext = (edittext) findviewbyid (R. id. input_label); spinner = (spinner) findviewbyid (R. id. spinner); list. setonitemclicklistener (this); button. setonclicklistener (n EW onclicklistener () {public void onclick (view v) {// todo auto-generated method stub string data = edittext. gettext (). tostring (). trim (); If (data. trim (). length ()> 0) {dbhelpe DB = new dbhelpe (getapplicationcontext (); dB. getwritabledatabase (); int A = 0; A = dB. getalllabels (). size (); dB. insertlabel (data); log. D ("DDD", DB. getalllabels (). size () + ""); If (dB. getalllabels (). size ()> A) {toast. maketext (geta Pplicationcontext (), "inserted successfully", toast. length_short ). show ();} else {toast. maketext (getapplicationcontext (), "insertion failed", toast. length_short ). show ();} log. D ("AA", A + ""); edittext. settext (""); inputmethodmanager Imm = (inputmethodmanager) getsystemservice (context. input_method_service); Imm. hidesoftinputfromwindow (edittext. getwindowtoken (), 0); loaddata ();} else {toast. maketext (getapplicationcontext (), "Enter Input data ", toast. length_short ). show () ;}}); loaddata () ;}public void loaddata () {dbhelpe DB = new dbhelpe (getapplicationcontext (); List <string> DATA = dB. getalllabels (); arrayadapter <string> adapter = new arrayadapter <string> (this, android. r. layout. simple_spinner_item, data); adapter. setdropdownviewresource (Android. r. layout. simple_spinner_dropdown_item); spinner. setadapter (adapter); arrayadapter <s Tring> listadapter = new arrayadapter <string> (this, android. r. layout. simple_list_item_1, data); list. setadapter (listadapter) ;}@ override public Boolean oncreateoptionsmenu (menu) {// inflate the menu; this adds items to the action bar if it is present. getmenuinflater (). inflate (R. menu. activity_main, menu); Return true ;}@ override public void onitemclick (adapterview <?> Arg0, view arg1, int arg2, long arg3) {// todo auto-generated method stub dbhelpe DB = new dbhelpe (getapplicationcontext (); dB. getreadabledatabase (); string data = arg0.getitematposition (arg2 ). tostring (); log. D ("Sss", data); dB. delete (data); loaddata ();}}