Dbopenhelper:
Package com.example.db_demo01. DB;
import Android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import Android.database.sqlite.SQLiteOpenHelper;
Public class Dbopenhelper extends sqliteopenhelper {
Private Static String Name = "Mydb.db"; Database name
Private Static int version = 1; Version number
Public Dbopenhelper (Context context) {
Super (Context, name, null, version);
}
@Override
Public void onCreate (sqlitedatabase db) {
String sql = "CREATE table person (ID integer primary key autoincrement, name varchar (+), address varchar (64))";
Db.execsql (SQL); Create a table
}
@Override
Public void Onupgrade (sqlitedatabase arg0, int arg1, int arg2) {
Update the version number at the same time when you update the table structure
}
}
Closure of the DB operation:
Package com.example.db_demo01. DB;
import java.util.ArrayList;
import Java.util.HashMap;
import java.util.List;
import Java.util.Map;
import Android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
Public class DB {
Private Dbopenhelper helper = null;
Public DB (Context context) {
Helper = New dbopenhelper (context);
}
Public Boolean Execsql (String sql) {
boolean flag = false;
Sqlitedatabase database = null;
Try {
Database = Helper.getwritabledatabase ();
Database.execsql (SQL);
Flag = true;
} catch (Exception e) {
E.printstacktrace ();
}finally{
if (Database! = null) {
Database.close ();
}
}
return flag;
}
Insert
Public Boolean Insert (String sql) {
return Execsql (SQL);
}
Delete
Public Boolean Delete (String sql) {
return Execsql (SQL);
}
Update
Public Boolean Update (String sql) {
return Execsql (SQL);
}
Inquire
Public List<map<string, string>> Query (String sql) {
Sqlitedatabase database = null;
list<map<string, string>> list = new arraylist<map<string, string>> ();
Try {
Database = Helper.getwritabledatabase ();
cursor cursor = database.rawquery (SQL, null);
int colums = Cursor.getcolumncount ();
while (Cursor.movetonext ()) {
map<string, string> map = new hashmap<string, string> ();
for (int i=0; i<colums; i++) {
String cols_name = Cursor.getcolumnname (i);
String Cols_value = cursor.getstring (Cursor.getcolumnindex (cols_name));
if (Cols_value = = null) {
Cols_value = "";
}
Map.put (Cols_name, Cols_value);
}
List.add (map);
}
} catch (Exception e) {
E.printstacktrace ();
}finally{
if (Database! = null) {
Database.close ();
}
}
return list;
}
}
Unit Test class:
Package com.example.db_demo01.test;
import java.util.ArrayList;
import java.util.List;
import Java.util.Map;
import android.test.AndroidTestCase;
Import com.example.db_demo01. Db. DB;
Import com.example.db_demo01. Db. Dbopenhelper;
Public class MyTest extends androidtestcase {
Public MyTest () {}
Public void Createdb () {
Dbopenhelper helper = new dbopenhelper (GetContext ());
Helper.getwritabledatabase ();
}
Public void Insert () {
DB db = new db (GetContext ());
String sql = "INSERT into person (name, address) VALUES (' Deng ', ' zhbit ')";
Db. Insert (SQL);
}
Public void Delete () {
DB db = new db (GetContext ());
String sql = "Delete from the person where name = ' Deng '";
System. out. println (db. Delete (SQL));
}
Public void Update () {
DB db = new db (GetContext ());
String sql = "Update person set name = ' Deng 2 ' where name = ' Deng '";
System. out. println (db. Delete (SQL));
}
Public void query () {
DB db = new db (getcontext());
String sql = "SELECT * from person";
list<map<string, string>> list = new arraylist<map<string, string>> ();
List = db. Query (SQL);
System. out. println (List.tostring ());
}
}
Android SQLite DB Package