Basic operation example of Android SQLite Database

Import android. app. activity; <br/> Import android. content. contentvalues; <br/> Import android. database. cursor; <br/> Import android. database. SQLite. sqlitedatabase; <br/> Import android. graphics. color; <br/> Import android. OS. bundle; <br/> Import android. view. keyevent; <br/> Import android. widget. linearlayout; <br/> Import android. widget. listadapter; <br/> Import android. widget. listview; <br/> Import android. Widget. simplecursoradapter; </P> <p> public class activity01 extends activity {<br/> Private Static int micount = 0; </P> <p>/* database object */<br/> private sqlitedatabase msqlitedatabase = NULL; </P> <p> private final static string database_name = "SQLite. DB "; </P> <p>/* Table name */<br/> private final static string table_name =" Table1 "; </P> <p>/* field in the table */<br/> private final static string table_id = "_ id"; </P> <p> private Final Static string table_num = "num"; </P> <p> private final static string table_data = "data "; </P> <p>/* SQL statement for creating a table */<br/> private final static string create_table = "CREATE TABLE" + table_name <br/> + "(" + table_id + "integer primary key, "+ table_num <br/> +" interger, "+ table_data +" text )"; </P> <p>/* linear Layout */<br/> linearlayout m_linearlayout = NULL; </P> <p>/* List View-display data in the database */<br/> listview m _ Listview = NULL; </P> <p> @ override <br/> Public void oncreate (bundle savedinstancestate) {<br/> super. oncreate (savedinstancestate); </P> <p>/* Create a linearlayout layout object */<br/> m_linearlayout = new linearlayout (this ); <br/>/* set the properties of the layout linearlayout */<br/> m_linearlayout.setorientation (linearlayout. vertical); <br/> m_linearlayout.setbackgroundcolor (Android. graphics. color. black); </P> <p>/* Create a listview object */<br/> M_L Istview = new listview (this); <br/> linearlayout. layoutparams Param = new linearlayout. layoutparams (<br/> linearlayout. layoutparams. fill_parent, <br/> linearlayout. layoutparams. wrap_content); <br/> m_listview.setbackgroundcolor (color. black); </P> <p>/* Add m_listview to m_linearlayout Layout */<br/> m_linearlayout.addview (m_listview, Param ); </P> <p>/* set to display m_linearlayout Layout */<br/> setcontentview (m_linearlayout); </ P> <p> // open an existing database <br/> msqlitedatabase = This. openorcreatedatabase (database_name, <br/> mode_private, null ); </P> <p> // obtain the database phones cursor <br/> try {<br/>/* Create a table in the database msqlitedatabase */<br/> msqlitedatabase.exe csql (create_table ); <br/>} catch (exception e) {<br/> updataadapter (); <br/>}</P> <p> Public Boolean onkeyup (INT keycode, keyevent event) {<br/> switch (keycode) {<br/> case keyevent. key Code_dpad_left: <br/> adddata (); <br/> break; <br/> case keyevent. keycode_dpad_right: <br/> deletedata (); <br/> break; <br/> case keyevent. keycode_1: <br/> updata (); <br/> break; <br/> case keyevent. keycode_2: <br/> deletetable (); <br/> break; <br/> case keyevent. keycode_3: <br/> deletedatabase (); <br/> break; <br/>}< br/> return true; <br/>}</P> <p>/* delete database */<br/> Public void deletedatabase () {<br/> This. delete Database (database_name); <br/> This. finish (); <br/>}</P> <p>/* delete a table */<br/> Public void deletetable () {<br/> msqlitedatabase.exe csql ("Drop table" + table_name); <br/> This. finish (); <br/>}</P> <p>/* update a data entry */<br/> Public void updata () {<br/> contentvalues CV = new contentvalues (); <br/> cv. put (table_num, micount); <br/> cv. put (table_data, "modified data" + micount); </P> <p>/* update data */<br/> msqlitedatabase. UPDA Te (table_name, CV, <br/> table_num + "=" + integer. tostring (micount-1), null); </P> <p> updataadapter (); <br/>}</P> <p>/* Add a data entry to the table */<br/> Public void adddata () {<br/> contentvalues CV = new contentvalues (); <br/> cv. put (table_num, micount); <br/> cv. put (table_data, "Test Database Data" + micount); <br/>/* insert data */<br/> msqlitedatabase. insert (table_name, null, CV); <br/> micount ++; <br/> updataadapter (); <br/>}</P> <P>/* delete a specified piece of data from the table */<br/> Public void deletedata () {<br/>/* delete data */<br/> msqlitedatabase.exe csql ("delete from" + table_name + "where _ id =" <br/> + integer. tostring (micount); </P> <p> micount --; <br/> If (micount <0) {<br/> micount = 0; <br/>}</P> <p> updataadapter (); <br/>}</P> <p>/* try to display more lines */<br/> Public void updataadapter () {<br/> // obtain the database phones cursor <br/> cursor cur = msqlitedatabase. query (table_n Ame, new string [] {table_id, <br/> table_num, table_data}, null, null); </P> <p> micount = cur. getcount (); <br/> If (cur! = NULL & cur. getcount ()> = 0) {<br/> // listadapter is a bridge between listview and background data <br/> listadapter adapter = new simplecursoradapter (this, <br/> // define the display template for each row in the list <br/> // indicates that each row contains two data items <br/> android. r. layout. simple_list_item_2, <br/> // database cursor object <br/> cur, <br/> // database cursor object <br/> New String [] {table_num, table_data },< br/> // views corresponding to name and number <br/> New int [] {android. r. id. text1, android. r. id. text2}); <br/>/* Add the adapter to m_listview */<br/> m_listview.setadapter (adapter ); <br/>}</P> <p>/* key event processing */<br/> Public Boolean onkeydown (INT keycode, keyevent event) {<br/> If (keycode = keyevent. keycode_back) {<br/>/* close the database (easy to forget) */<br/> msqlitedatabase. close (); <br/> This. finish (); <br/> return true; <br/>}< br/> return Super. onkeydown (keycode, event); <br/>}</P> <p>}

8

The above test data 8 was previously created ..