SQL about time operations in Android

SQL has the type of time, Date,time,datetime, convenient for the maintenance of records, the following demo shows how to add time by default in each record

SOURCE http://www.codes51.com/code/detail_1460.html

1. First the Databasehelper class, where a table is built to hold a book, including the title, author.

Package Com.chaoyue.sqldemo;import Android.content.contentvalues;import Android.content.context;import Android.database.cursor;import Android.database.sqlite.sqlitedatabase;import Android.database.sqlite.sqliteopenhelper;public class Databasehelper extends Sqliteopenhelper {private final static string database_name = "Books.db";p rivate final static int database_version = 1;public final static String table_name = "b  Ooks_table ";p ublic final static string book_id =" book_id ";p ublic final static string book_name =" Book_name ";p ublic final static String Book_author = "Book_author";p ublic databasehelper (Context context) {//TODO auto-generated constructor stub Super (context, database_name, NULL, database_version);} Create Table@overridepublic void OnCreate (Sqlitedatabase db) {String sql = "Create TABLE" + table_name + "(" + book_id+ " INTEGER primary Key AutoIncrement, "+ book_name+" text, "+ Book_author +" text, oderdate DATETIME DEFAULT current_time STAMP); "; Db.execsql (SQL);} @OverridepuBlic void Onupgrade (sqlitedatabase db, int oldversion, int newversion) {String sql = "DROP TABLE IF EXISTS" + table_name; Db.execsql (SQL); onCreate (db);} Public Cursor Select () {Sqlitedatabase db = This.getreadabledatabase (); cursor cursor = DB.QUERY (table_name, NULL, NULL, NULL, NULL, NULL, NULL); return cursor; Add operation public Long Insert (string bookname, string author) {Sqlitedatabase db = This.getwritabledatabase ();/* Contentvalue s */contentvalues cv = new Contentvalues () cv.put (Book_name, bookname); Cv.put (Book_author, AUTHOR); Long row = Db.insert ( TABLE_NAME, NULL, CV); return row;} Delete operation public void delete (int id) {Sqliedatabase db = This.getwritabledatabase (); String where = book_id + "=?"; String[] Wherevalue = {integer.tostring (id)};d b.delete (table_name, where, wherevalue);} Modify Operation public void update (int id, string bookname, string author) {Sqlitedatabase db = This.getwritabledatabase (); String where = book_id + "=?"; String[] Wherevalue = {integer.tostring (id)}; Contentvalues CV =New Contentvalues (); Cv.put (Book_name, bookname); Cv.put (Book_author, AUTHOR);d b.update (TABLE_NAME, CV, where, Wherevalue);} Public Sqlitedatabase Getdb () {Sqlitedatabase db = This.getreadabledatabase (); return db;}}

Simple application in 2.mainactivity class

It classic Laugh quote: system programmer: 1, scalp often numbness, in the sight of a blue screen is more obvious, in the screen is not visible when the time is particularly obvious; 2, when the elevator is always worried about the crash, and the wall to find the reset key; 3, the nail is very long, Because according to F7 to F12 relatively labor-saving, 4, as long as there is something in the hand, and kept pressing, thought is alt-f, s;5, the chassis never on the lid, in order to determine whether the hard disk is turning; 6, often inexplicably tracking others, hands kept pressing F10;7, all the interfaces are plugged in the hard disk, Therefore, 26 letters are not enough, 8, a free to say "next life does not do programmers", 9, always think 9th is a number, 10, not afraid of the virus, but very afraid of their own procedures;

Package Com.chaoyue.sqldemo;import Android.app.activity;import Android.database.cursor;import android.os.Bundle; Import Android.util.log;public class Mainactivity extends Activity {@Overrideprotected void OnCreate (Bundle Savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.activity_main);D Atabasehelper Databasehelper = new Databasehelper (this);d atabasehelper.getdb (). Delete (databasehelper.table_name, NULL, NULL); Databasehelper.insert ("A", "AA");d Atabasehelper.insert ("b", "BB");d Atabasehelper.insert ("C", "CC"); Databasehelper.insert ("D", "DD");d Atabasehelper.insert ("E", "ee");d Atabasehelper.insert ("F", "FF"); cursor cursor = Databasehelper.select (); while (Cursor.movetonext ()) {String name = cursor.getstring ( Cursor.getcolumnindex ("Book_name")); String author = cursor.getstring (Cursor.getcolumnindex ("Book_author")); String oderdate = cursor.getstring (Cursor.getcolumnindex ("oderdate")); LOG.D ("", "Chaoyue name=" + name + "author=" + author+ "oderdate=" +oderdate);} CuRsor.close ();}} 

3. For more operation and type of time refer to official documentation http://www.sqlite.org/lang_datefunc.html

SQL about time operations in Android