看了很多关于android使用sqlite数据库的文章，很多都是介绍了数据库的建立和表的建立，而表通常都是只建立一张，而实际情况我们用到的表可能不止一张，那这种情况下我们又该怎么办呢，好了，下面我教大家如何在sqlite数据库中建立多张表。
首先是如何建立数据库和表：
建立一个类继承SQLiteOpenHelper，即：
public class ReaderOpenHelper extends SQLiteOpenHelper
然后添加构造方法：
public ReaderOpenHelper(Context context) {
super(context, "people.db", null, 1);
}
people.db是数据库名字，1是数据库版本。
然后在该类实现以下两个方法：
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub db.execSQL("create table readers(renumber integer primary key,rename text,retype text,reage text,rephone text,usename integer,password integer,createtime text)"); db.execSQL("create table books(booknumber integer primary key,bookname text,booktype text,bookeditor text,intime text,incounts integer)"); }
db.execSQL的作用是执行SQL语句，create table readers是创建一个叫readers的表，括号里就是各个字段名和值类型。
这里创建了两张表。另一张叫books
继续实现：
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub db.execSQL("drop if table exists readers"); db.execSQL("drop if table exists books"); onCreate(db); }
执行Sql语句"drop if table exists 表名"
这样你的sqlite数据库和两张表就创建完成了。
接下来再建一个数据库manager类，如：
public class ReaderManager
添加一个构造方法
public ReaderManager(Context conetxt) {
this.context = context;
readerOpenHelper = new ReaderOpenHelper(conetxt); }
然后添加表的操作方法：
package com.zhou.db;
import java.util.ArrayList;
import java.util.List; import com.zhou.utils.Books; import com.zhou.utils.Reader; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.util.Log; public class ReaderManager { ReaderOpenHelper readerOpenHelper; Context context; public ReaderManager(Context conetxt) { this.context = context; readerOpenHelper = new ReaderOpenHelper(conetxt); } // 增加读者 public void addSQL(Reader reader) { SQLiteDatabase db = null; try { db = readerOpenHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("renumber", reader.getReNumber()); values.put("rename", reader.getName()); values.put("retype", reader.getSex()); values.put("reage", reader.getAge()); values.put("rephone", reader.getPhoneNumber()); values.put("createtime", reader.getCreateTime()); values.put("usename", reader.getUseName()); values.put("password", reader.getPassword()); db.insert("readers", null, values); } catch (Exception e) { // TODO: handle exception } finally { db.close(); } } // 增加图书 public void bookAddSQL(Books book) { SQLiteDatabase db = null; try { db = readerOpenHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("booknumber", book.getBookNumber()); values.put("bookname", book.getBookName()); values.put("booktype", book.getBookType()); values.put("bookeditor", book.getBookEditer()); values.put("intime", book.getInTime()); values.put("incounts", book.getCount()); db.insert("books", null, values); } catch (Exception e) { // TODO: handle exception } finally { db.close(); } } // 读者查询 public List<Reader> selectSQL() { List<Reader> list = new ArrayList<Reader>(); SQLiteDatabase db = null; // 获取一个光标对象 Cursor cursor = null; try { db = readerOpenHelper.getReadableDatabase(); cursor = db.query("readers", null, null, null, null, null, null); Reader reader = null; while (cursor.moveToNext()) { reader = new Reader(); reader.setReNumber(cursor.getInt(cursor .getColumnIndex("renumber"))); reader.setName(cursor.getString(cursor.getColumnIndex("rename"))); reader.setSex(cursor.getString(cursor.getColumnIndex("retype"))); reader.setAge(cursor.getString(cursor.getColumnIndex("reage"))); reader.setPhoneNumber(cursor.getString(cursor .getColumnIndex("rephone"))); reader.setCreateTime(cursor.getString(cursor .getColumnIndex("createtime"))); reader.setUseName(cursor.getInt(cursor .getColumnIndex("usename"))); reader.setPassword(cursor.getInt(cursor .getColumnIndex("password"))); list.add(reader); } } catch (Exception e) { // TODO: handle exception } finally { cursor.close(); db.close(); } return list; } // 图书查询 public List<Books> bookSelectSQL() { List<Books> list = new ArrayList<Books>(); SQLiteDatabase db = null; // 获取一个光标对象 Cursor cursor = null; try { db = readerOpenHelper.getReadableDatabase(); cursor = db.query("books", null, null, null, null, null, null); Books book = null; while (cursor.moveToNext()) { book = new Books(); book.setBookNumber(cursor.getInt(cursor .getColumnIndex("booknumber"))); book.setBookName(cursor.getString(cursor .getColumnIndex("bookname"))); book.setBookType(cursor.getString(cursor .getColumnIndex("booktype"))); book.setBookEditer(cursor.getString(cursor .getColumnIndex("bookeditor"))); book.setInTime(cursor.getString(cursor.getColumnIndex("intime"))); book.setCount(cursor.getInt(cursor.getColumnIndex("incounts"))); Log.d("TAGG", cursor.getString(cursor.getColumnIndex("intime"))); list.add(book); } } catch (Exception e) { // TODO: handle exception } finally { cursor.close(); db.close(); } return list; } // 读者删除 public void deleteSQL(final long id) { SQLiteDatabase db = null; try { db = readerOpenHelper.getWritableDatabase(); db.delete("readers", "renumber=" + id, null); } catch (Exception e) { } finally { db.close(); } } // 读者更新 public void updateData(int id, String name, String sex, String age, String phoneNumber, int password) { SQLiteDatabase db = null; try { db = readerOpenHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("rename", name); values.put("retype", sex); values.put("reage", age); values.put("rephone", phoneNumber); values.put("password", password); db.update("readers", values, "renumber=" + id, null); } catch (Exception e) { // TODO: handle exception } finally { db.close(); } } // public long getCount() { // // Cursor cursor = null; // long count = 0; // SQLiteDatabase db = null; // try { // db = readerOpenHelper.getWritableDatabase(); // cursor = db.query("readers", null, null, null, null, null, null); // // if (null != cursor) { // count = cursor.getCount(); // cursor.close(); // } // } catch (Exception e) { // } finally { // db.close(); //