SQLite以其体积小，功能比完善而得到众多android开发者的青睐，今天，主要来讨论数据库的一般操作。
//创建或打开数据库的方法 public static void createOrOpenDatabase() { try { sld=SQLiteDatabase.openDatabase ( "/data/data/com.bn.lc/mydb", //数据库所在路径 null, //CursorFactory SQLiteDatabase.OPEN_READWRITE|SQLiteDatabase.CREATE_IF_NECESSARY //读写、若不存在则创建 ); //收入 String sql01="create table if not exists Income" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "idate char(10)," + "isource Varchar(20)," + "imoney Integer," + "imemo Varchar(50)" + ")"; //收入类别 String sql02="create table if not exists Scy" + //收入类别 "("+ "icategory Varchar(10) PRIMARY KEY ," + "says varchar(50)" + ")"; //花费 String sql03="create table if not exists Spend" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "idate char(10)," + "isource Varchar(20)," + "imoney Integer," + "imemo Varchar(50)" + ")"; //支出 String sql04="create table if not exists Zcy" + //支出类别 "(" + "icategory Varchar(10) PRIMARY KEY," + "says Varchar(50)" + ")"; //个人信息 String sql05="create table if not exists PersonDate" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "isex char(1)," + "idate varchar(10)," + "iage varchar(2)," + "iblood varchar(5)," + "iprovince varchar(5)," + "icity varchar(5)," + "iemail varchar(15)," + "ioldpwd varchar(6)" + ")"; sld.execSQL(sql01); sld.execSQL(sql02); sld.execSQL(sql03); sld.execSQL(sql04); sld.execSQL(sql05); } catch(Exception e) { e.printStackTrace(); } }
以上是建立、创建数据库。
下面讲解插入操作：
//类别维护插入方法 public static void insertCategory(String str,String str0,String str1) { try { String sql="insert into "+str0+" values('"+str+"','"+str1+"');"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } }
查询方法：
//类别维护查询的方法 public static List<String> queryCategory(String str) { List<String> addcategory=new ArrayList<String>(); try { String sql="select * from "+str+";"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { addcategory.add(cur.getString(0)); addcategory.add(cur.getString(1)); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return addcategory; }
删除信息的方法：
//类别的删除信息 public static void deleteValuesFromTable(String tablename,String colname,String getstr) { try { String sql="delete from "+tablename+" where "+colname+"='"+getstr+"';"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } }
日常信息插入：
//日常收入插入记录的方法 public static void insert(String tableName) { int money=Integer.parseInt(Lc_Activity.Imoney01); try { String sql="insert into '"+tableName+"' values(null,'"+Lc_Activity.Idate01+"'," + "'"+Lc_Activity.Isource+"','"+money+"','"+Lc_Activity.Imemo+"')"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } }
关闭数据库的方法：、
//关闭数据库的方法 public static void closeDatabase() { try { sld.close(); } catch(Exception e) { e.printStackTrace(); } }
最后，我建立了一个工具类，以后如果用到可以直接使用：
package com.bn.lc; import java.util.ArrayList; import java.util.List; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; public class DBUtil { public static SQLiteDatabase sld; public static Lc_Activity activity; //创建或打开数据库的方法 public static void createOrOpenDatabase() { try { sld=SQLiteDatabase.openDatabase ( "/data/data/com.bn.lc/mydb", //数据库所在路径 null, //CursorFactory SQLiteDatabase.OPEN_READWRITE|SQLiteDatabase.CREATE_IF_NECESSARY //读写、若不存在则创建 ); //收入 String sql01="create table if not exists Income" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "idate char(10)," + "isource Varchar(20)," + "imoney Integer," + "imemo Varchar(50)" + ")"; //收入类别 String sql02="create table if not exists Scy" + //收入类别 "("+ "icategory Varchar(10) PRIMARY KEY ," + "says varchar(50)" + ")"; //花费 String sql03="create table if not exists Spend" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "idate char(10)," + "isource Varchar(20)," + "imoney Integer," + "imemo Varchar(50)" + ")"; //支出 String sql04="create table if not exists Zcy" + //支出类别 "(" + "icategory Varchar(10) PRIMARY KEY," + "says Varchar(50)" + ")"; //个人信息 String sql05="create table if not exists PersonDate" + "(" + "id INTEGER PRIMARY KEY AUTOINCREMENT," + "isex char(1)," + "idate varchar(10)," + "iage varchar(2)," + "iblood varchar(5)," + "iprovince varchar(5)," + "icity varchar(5)," + "iemail varchar(15)," + "ioldpwd varchar(6)" + ")"; sld.execSQL(sql01); sld.execSQL(sql02); sld.execSQL(sql03); sld.execSQL(sql04); sld.execSQL(sql05); } catch(Exception e) { e.printStackTrace(); } } //类别维护插入方法 public static void insertCategory(String str,String str0,String str1) { try { String sql="insert into "+str0+" values('"+str+"','"+str1+"');"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //类别维护查询的方法 public static List<String> queryCategory(String str) { List<String> addcategory=new ArrayList<String>(); try { String sql="select * from "+str+";"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { addcategory.add(cur.getString(0)); addcategory.add(cur.getString(1)); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return addcategory; } //类别的删除信息 public static void deleteValuesFromTable(String tablename,String colname,String getstr) { try { String sql="delete from "+tablename+" where "+colname+"='"+getstr+"';"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //日常收入插入记录的方法 public static void insert(String tableName) { int money=Integer.parseInt(Lc_Activity.Imoney01); try { String sql="insert into '"+tableName+"' values(null,'"+Lc_Activity.Idate01+"'," + "'"+Lc_Activity.Isource+"','"+money+"','"+Lc_Activity.Imemo+"')"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //收入 支出查询 public static List<String> queryIncome(String tableName, int state) { List<String> IncomeSpeedSelect=new ArrayList<String>(); try { if(state==1) { //checkBox1 checkBox2 checkBox3都被选中的情况 String sql1="select * from '"+tableName+"' where " + "idate between '"+Lc_Activity.Idate01+"' AND '"+Lc_Activity.Idate02+"' " + "and imoney between '"+Integer.parseInt(Lc_Activity.Imoney01)+"' " + "and '"+Integer.parseInt(Lc_Activity.Imoney02)+"' " + "and isource='"+Lc_Activity.Isource+"';"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==2) {//checkBox1 checkBox2 都被选中的情况 String sql1="select * from '"+tableName+"' where " + "idate between '"+Lc_Activity.Idate01+"' AND '"+Lc_Activity.Idate02+"' " + "and imoney between '"+Integer.parseInt(Lc_Activity.Imoney01)+"' " + "and '"+Integer.parseInt(Lc_Activity.Imoney02)+"' ;"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==3) {//checkBox1 checkBox3都被选中的情况 String sql1="select * from '"+tableName+"' where " + "idate between '"+Lc_Activity.Idate01+"' AND '"+Lc_Activity.Idate02+"' " + "and isource='"+Lc_Activity.Isource+"';"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==4) {// checkBox2 checkBox3都被选中的情况 String sql1="select * from '"+tableName+"' " + "where imoney between '"+Integer.parseInt(Lc_Activity.Imoney01)+"' " + "and '"+Integer.parseInt(Lc_Activity.Imoney02)+"' " + "and isource='"+Lc_Activity.Isource+"';"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==5) {// checkBox1 都被选中的情况 String sql1="select * from '"+tableName+"' where " + "idate between '"+Lc_Activity.Idate01+"' AND '"+Lc_Activity.Idate02+"' ;"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==6) {// checkBox2 都被选中的情况 String sql1="select * from '"+tableName+"' where " + "imoney between '"+Integer.parseInt(Lc_Activity.Imoney01)+"'" + " and '"+Integer.parseInt(Lc_Activity.Imoney02)+"' ;"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } if(state==7) {// checkBox3 都被选中的情况 String sql1="select * from '"+tableName+"' where isource='"+Lc_Activity.Isource+"' ;"; Cursor cur=sld.rawQuery(sql1, new String[]{}); while(cur.moveToNext()) { IncomeSpeedSelect.add(cur.getString(1)); IncomeSpeedSelect.add(cur.getString(2)); IncomeSpeedSelect.add(cur.getString(3)); IncomeSpeedSelect.add(cur.getString(4)); } cur.close(); } } catch(Exception e) { e.printStackTrace(); } return IncomeSpeedSelect; } //收入支出查询 只有表名 public static List<String> queryTable(String tableName) { List<String> slist=new ArrayList<String>(); try { String sql="select * from "+tableName+";"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { slist.add(cur.getString(1)); slist.add(cur.getString(2)); slist.add(cur.getString(3)); slist.add(cur.getString(4)); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return slist; } //收入或支出的类别的查询 public static List<String> getIsource(String tableName) { List<String> alist=new ArrayList<String>(); try { String sql="select isource from "+tableName; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { alist.add(cur.getString(0)); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return alist; } //获得对应表的同类的总和 public static List<String> getSum(String tableName,int state) { List<String> sumSelect=new ArrayList<String>(); if(state==1) { try { String sql="select sum(imoney) from "+tableName+" " + "where idate between '"+Lc_Activity.Idate01+"' AND '"+Lc_Activity.Idate02+"' ;"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { sumSelect.add(cur.getString(0)); } } catch(Exception e) { e.printStackTrace(); } return sumSelect; } if(state==2) { try { String sql="select sum(imoney) from "+tableName+" where isource= '"+Lc_Activity.Isource+"';"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { sumSelect.add(cur.getString(0)); } } catch(Exception e) { e.printStackTrace(); } return sumSelect; } if(state==3) { try { String sql="select sum(imoney) from '"+tableName+"' " + "where (isource= '"+Lc_Activity.Isource+"') " + "and idate between '"+Lc_Activity.Idate01+"' and '"+Lc_Activity.Idate02+"' ;"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { sumSelect.add(cur.getString(0)); } } catch(Exception e) { e.printStackTrace(); } return sumSelect; } return sumSelect; } //查询个人信息 public static String getPassword() { String result=null; try { String sql="select Ioldpwd from PersonDate;"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { result=cur.getString(0); System.out.println(result); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return result; } //插入个人信息 public static void InsertPersonDate() { try { String sql="insert into PersonDate values(1,'"+Lc_Activity.sexDate+"'," + "'"+Lc_Activity.Idate01+"','"+Lc_Activity.Iage+"','"+Lc_Activity.bloodDate+"'," + "'"+Lc_Activity.priovinceDate+"','"+Lc_Activity.cityDate+"','"+Lc_Activity.Iemail+"'," + "'"+Lc_Activity.Ioldpwd+"');"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //更改个人信息 public static void UpdatePersonDate() { try { String sql="update PersonDate set isex='"+Lc_Activity.sexDate+"'," + "idate='"+Lc_Activity.Idate01+"',iage='"+Lc_Activity.Iage+"'," + "iblood='"+Lc_Activity.bloodDate+"'," + "iprovince='"+Lc_Activity.priovinceDate+"',icity='"+Lc_Activity.cityDate+"'," + "iemail='"+Lc_Activity.Iemail+"',ioldpwd='"+Lc_Activity.Inewpwd+"' where id=1;"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //查询表中的数据 public static List<String> getAllInformation(String time,String source,String money,String tableName) { List<String> slist=new ArrayList<String>(); try { String sql="select * from "+tableName+" where idate='"+time+ "' and isource='"+source+"' and imoney='"+money+"';"; Cursor cur=sld.rawQuery(sql, new String[]{}); while(cur.moveToNext()) { slist.add(cur.getString(0)); slist.add(cur.getString(1)); slist.add(cur.getString(2)); slist.add(cur.getString(3)); slist.add(cur.getString(4)); } cur.close(); } catch(Exception e) { e.printStackTrace(); } return slist; } //删除表中的某一条记录 (收入 支出查询详细信息的删除功能) public static void deleteFromTable(int id,String str) { try { String sql="delete from "+str+" where id="+id+";"; sld.execSQL(sql); } catch(Exception e) { e.printStackTrace(); } } //关闭数据库的方法 public static void closeDatabase() { try { sld.close(); } catch(Exception e) { e.printStackTrace(); } } }