吾生也有涯,而知也无涯。这篇文章主要讲述Android开发工程师文集-1 小时学会SQLite相关的知识，希望能为你提供帮助。
前言大家好，给大家带来android开发工程师文集-1 小时学会SQLite的概述，希望你们喜欢
内容

• 什么是Sqlite：
  效率高，开源，小型，程序驱动，支持事务操作，无数据类型，可嵌入的关系型数据库
  独立的，跨平台的，代码量少，简单易用

创建表语句

create table student(_id Integer primary key, name varchar(10), age Integer not null);

删除表

drop table student;

插入数据

Insert into 表名(字段列表) values (值列表); insert into student(_id,age) values(1,17); insert into student values(1," vic" ,17);

修改数据

update student set name=" vic" ,age=17 where _id=1;

更新数据

Update 表名 set 字段=值 列表 更新的条件

删除数据

delete from 表名 [删除条件]; delete from student where _id=1;

查询语句

select 字段名 from 表名称 [查询条件]; select 列名称 from 表名称 where 条件; group by 分组的字段 having 筛选条件 order by 排序字段; select * from student; select _id from student; select * from student where _id=1; select * from student where _id=1 and age> 17; select * from student where age like " %1%" ; select * from student where age> 17 order by _id=1;

内容

• 创建数据库
• 实现数据库中的增删改查

要点【Android开发工程师文集-1 小时学会SQLite】SQLiteOpenHelper,onCreate(),onUpgrade(),onOpen()

< ?xml version=" 1.0" encoding=" utf-8" ?> < LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android" android:layout_width=" match_parent" android:layout_height=" match_parent" android:background=" @drawable/login_bg" android:orientation=" vertical" > < Button android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 创建" android:onClick=" create" android:background=" #000000" /> < /LinearLayout>

//MainActivity.java public class MainActivity extends AppCompatActivity { private mysqliteHelper helper; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); helper = DbManger.getIntance(this); } public void createdb(View view){ SQLiteDatabase db=helper.getWritableDatable(); } }

//创建一个类 //sqliteOpenHelper //提供了onCreate()和onUpgrade()与onOpen() public class MySqliteHelper extends SQLiteOpenHelper{ public MySqliteHelper(Context context, String name, SQLitebase.CursorFactory factory, int version){ super(context,name,factory,version); } public MySqliteHelper(Context context){ super(context,Constant.DATABASE_NAME,null,Constant.DATABASE_VERSION); } //数据库创建时回调 @Override public void onCreate(SQLiteDatabase db){ Log.i(" tag" ," --onCreate--" ); //String sql=" create table student(_id Integer primary key,name verchar(10),age Integer)" ; String sql = " create table " +Constant.TABLE_NAME+" (" +Constant._ID+" Integer primary key," +Constant.NAME+" varchar(10)," +Constant.AGE+" Integer)" ; db.execSQL(sql); //执行数据库语句 } //数据库更新 @Override public void onUpgrade(SQLiteDatabase db,int oldVersion, int newVersion){ Log.i(" tag" ," --onUpgrade--" ); } //数据库打开 @Override public void onOpen(SQLiteDatabase db){ super.onOpen(db); Log.i(" tag" ," --onOpen--" ); } }

//创建库表 public class Contant{ public static final String DATABASE_NAME=“info.db”; //数据库名称 public static final int DATABASE_VERSION=1; //数据库的版本号 public static final String TABLE_NAME=" student" ; //表名 //用这里表示 public static final String _ID=" _id" ; public static final String _NAME=" name" ; public static final String AGE=" age" ;

public class DbManger{ private static MySqliteHelper helper; public static MySqliteHelper getIntance(Context context){ if(helper == null){ helper=new MySqliteHelper(content); } return hepler; } }

< ?xml version=" 1.0" encoding=" utf-8" ?> < LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android" android:layout_width=" match_parent" android:layout_height=" match_parent" android:background=" @drawable/login_bg" android:orientation=" vertical" > < Button android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 创建" android:onClick=" create" android:background=" #000000" /> < Button android:id=" @+id/btn_insert" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < /LinearLayout>

//MainActivity.java public class MainActivity extends AppCompatActivity { private MySqliteHelper helper; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); helper = DbManger.getIntance(this); } public void createdb(View view){ SQLiteDatabase db=helper.getWritableDatable(); } public void click(View view){ switch(view.getId()){ case R.id.btn_insert: SQLiteDatabase db=helper.getWritableDatabase(); String sql=" insert into " +Constant.TABLE_NAME+" values(1,' vic' ,17)" ; DbManger.execSQL(db,sql); String sql2=" insert into " +Constant.TABLE_NAME+" values(2,' vic' ,23)" ; DbManger.execSQL(db,sql2); db.close(); break; } }

public class DbManger{ private static MySqliteHelper helper; public static MySqliteHelper getIntance(Context context){ if(helper == null){ helper=new MySqliteHelper(content); } return hepler; } public static void execSQL(SQLiteDatabase db,String sql){ if(db!=null){ if(sql!=null & & !" " .equals(sql)){ db.execSQL(sql); } } }

< ?xml version=" 1.0" encoding=" utf-8" ?> < LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android" android:layout_width=" match_parent" android:layout_height=" match_parent" android:background=" @drawable/login_bg" android:orientation=" vertical" > < Button android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 创建" android:onClick=" create" android:background=" #000000" /> < Button android:id=" @+id/btn_insert" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_update" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 修改数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < /LinearLayout>

//MainActivity.java public class MainActivity extends AppCompatActivity { private MySqliteHelper helper; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); helper = DbManger.getIntance(this); } public void createdb(View view){ SQLiteDatabase db=helper.getWritableDatable(); } public void click(View view){ switch(view.getId()){ case R.id.btn_insert: SQLiteDatabase db=helper.getWritableDatabase(); String sql=" insert into " +Constant.TABLE_NAME+" values(1,' vic' ,17)" ; DbManger.execSQL(db,sql); String sql2=" insert into " +Constant.TABLE_NAME+" values(2,' vic' ,23)" ; DbManger.execSQL(db,sql2); db.close(); break; case R.id.btn_update: db=helper.getWritableDatabase(); String updateSql=" update " +Constant.TABLE_NAME" +" set " +Contant.NAME+" =' vic2' where " +Contant._ID+" =1" ; DbManger.execSQL(db,updateSql); db.close(); break; } }

< ?xml version=" 1.0" encoding=" utf-8" ?> < LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android" android:layout_width=" match_parent" android:layout_height=" match_parent" android:background=" @drawable/login_bg" android:orientation=" vertical" > < Button android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 创建" android:onClick=" create" android:background=" #000000" /> < Button android:id=" @+id/btn_insert" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_update" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 修改数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_delete" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 删除数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < /LinearLayout>

//MainActivity.java public class MainActivity extends AppCompatActivity { private MySqliteHelper helper; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); helper = DbManger.getIntance(this); } public void createdb(View view){ SQLiteDatabase db=helper.getWritableDatable(); } public void click(View view){ switch(view.getId()){ case R.id.btn_insert: SQLiteDatabase db=helper.getWritableDatabase(); String sql=" insert into " +Constant.TABLE_NAME+" values(1,' vic' ,17)" ; DbManger.execSQL(db,sql); String sql2=" insert into " +Constant.TABLE_NAME+" values(2,' vic' ,23)" ; DbManger.execSQL(db,sql2); db.close(); break; case R.id.btn_update: db=helper.getWritableDatabase(); String updateSql=" update " +Constant.TABLE_NAME" +" set " +Contant.NAME+" =' vic2' where " +Contant._ID+" =1" ; DbManger.execSQL(db,updateSql); db.close(); break; case R.id.btn_delete: db=helper.getWritableDatabase(); String delSql=" delete from " +Constant.TABLE_NAME+" where " +Constant._ID+" =2" ; DbManger.execSQL(db,delSql); db.close(); break; } }

< ?xml version=" 1.0" encoding=" utf-8" ?> < LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android" android:layout_width=" match_parent" android:layout_height=" match_parent" android:background=" @drawable/login_bg" android:orientation=" vertical" > < Button android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 创建" android:onClick=" create" android:background=" #000000" /> < Button android:id=" @+id/btn_insert" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_update" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 修改数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_delete" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 删除数据" android:onClick=" click" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_insertApi" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" onclick" android:layout_marginTop=" 15dp" android:background=" #000000" /> < /LinearLayout>

//MainActivity.java public class MainActivity extends AppCompatActivity { private MySqliteHelper helper; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); helper = DbManger.getIntance(this); } public void createdb(View view){ SQLiteDatabase db=helper.getWritableDatable(); } public void onClick(View view){ switch(view.getId()){ case R.id.btn_insertApi: SQLiteDatabase db=helper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put(Constant._ID,3); values.put(Constant.NAME," vic" ); values.put(Constant.AGE,17); long result=db.insert(Constant.TABLE_NAME,null,values); if(result> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; } } public void click(View view){ switch(view.getId()){ case R.id.btn_insert: SQLiteDatabase db=helper.getWritableDatabase(); String sql=" insert into " +Constant.TABLE_NAME+" values(1,' vic' ,17)" ; DbManger.execSQL(db,sql); String sql2=" insert into " +Constant.TABLE_NAME+" values(2,' vic' ,23)" ; DbManger.execSQL(db,sql2); db.close(); break; case R.id.btn_update: db=helper.getWritableDatabase(); String updateSql=" update " +Constant.TABLE_NAME" +" set " +Contant.NAME+" =' vic2' where " +Contant._ID+" =1" ; DbManger.execSQL(db,updateSql); db.close(); break; case R.id.btn_delete: db=helper.getWritableDatabase(); String delSql=" delete from " +Constant.TABLE_NAME+" where " +Constant._ID+" =2" ; DbManger.execSQL(db,delSql); db.close(); break; } }

< Button android:id=" @+id/btn_insertApi" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 插入数据" android:onClick=" onclick" android:layout_marginTop=" 15dp" android:background=" #000000" /> < Button android:id=" @+id/btn_updateApi" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 更新数据" android:onClick=" onclick" android:layout_marginTop=" 15dp" android:background=" #000000" />

public void onClick(View view){ switch(view.getId()){ case R.id.btn_insertApi: SQLiteDatabase db=helper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put(Constant._ID,3); values.put(Constant.NAME," vic" ); values.put(Constant.AGE,17); long result=db.insert(Constant.TABLE_NAME,null,values); if(result> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; case R.id.btn_updateApi: //String table 修改的数据表的名称,ContentValues values,String whereClause 表示修改条件,String[] whereArgs db=helper.getWritableDatabase(); //db.update(String table,ContentValues values,String whereClause,String[] whereArgs); ContentValues cv=new ContentValues(); cv.put(Contant.NAME," vic3" ); int count=db.update(Constant.TABLE_NAME,cv,Contant.TABLE_NAME,cv,Constant._ID+" =?" ,new String[]{" 3" }); if(count> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; } }

< Button android:id=" @+id/btn_updateApi" android:layout_width=" wrap_content" android:layout_height=" wrap_content" android:text=" 更新数据" android:onClick=" onclick" android:layout_marginTop=" 15dp" android:background=" #000000" />

public void onClick(View view){ switch(view.getId()){ case R.id.btn_insertApi: SQLiteDatabase db=helper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put(Constant._ID,3); values.put(Constant.NAME," vic" ); values.put(Constant.AGE,17); long result=db.insert(Constant.TABLE_NAME,null,values); if(result> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; case R.id.btn_updateApi: //String table 修改的数据表的名称,ContentValues values,String whereClause 表示修改条件,String[] whereArgs db=helper.getWritableDatabase(); //db.update(String table,ContentValues values,String whereClause,String[] whereArgs); ContentValues cv=new ContentValues(); cv.put(Contant.NAME," vic3" ); int count=db.update(Constant.TABLE_NAME,cv,Contant.TABLE_NAME,cv,Constant._ID+" =?" ,new String[]{" 3" }); if(count> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; case R.id.btn_deleteApi: db=helper.getWritableDatabase(); //int count2=db.delete(String table,StringwhereClause,String[] whereArgs); int count2=db.delete(Constant.TABLE_NAME,Constant._ID+" =?" ,new String[]{" 1" }); if(count2> 0){ Toast.makeText(MainActivity.this," 插入数据成功!" ,Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this," 插入数据失败!" ,Toast.LENGTH_LONG).show(); } db.close(); break; }

public int delete(String table,String whereClause,String[] whereArgs){ acquireReference(); try{ SQLiteStatement statement = new SQLiteStatement(this," DELETE FROM " +table+(!TextUtils.isEmpty(whereClause) ? " WHERE " +whereClause : " " ), whereArgs; try{ return statement.executeUpdateDelete(); }finally{ statement.close(); } }finally{ releaseReference(); }

总结

• 本文讲了Android开发工程师文集-1 小时学会SQLite，如果您还有更好地理解，欢迎沟通
• 定位：分享 Android& Java知识点，有兴趣可以继续关注

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