本文共 4640 字，大约阅读时间需要 15 分钟。
1. 创建一个SQLiteOpenHelper继承类
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | public class MySQLiteHelper extends SQLiteOpenHelper { //重写构造方法,可以改为(Context context, int version)只要这两参数 public MySQLiteHelper(Context context, String name, CursorFactory factory, int version) { super (context, "test.db" , null , version); } //创建表 @Override public void onCreate(SQLiteDatabase db) { db.execSQL( "CREATE TABLE person(personid INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),phone VARCHAR(20))" ); db.execSQL( "CREATE TABLE student(personid INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),phone VARCHAR(20))" ); } //升级表（当Database的Version低于当前new里的Version，直接执行下面方法） @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { int v = newVersion - oldVersion; switch (v) { case 3 : db.execSQL( "ALTER TABLE person ADD salary3 VARCHAR(20)" ); case 2 : db.execSQL( "ALTER TABLE person ADD salary2 VARCHAR(20)" ); case 1 : db.execSQL( "ALTER TABLE person ADD salary1 VARCHAR(20)" ); default : break ; } } } |
2.使用SQLite增删改查
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 | /** * CREATE TABLE person ( personid INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(20), phone VARCHAR(20) ) DROP TABLE person //删除表 INSERT INTO person(name,phone) VALUES ("rongqin","1598088588") //插入 SELECT * FROM person WHERE name="Andfeel" UPDATE person SET name="Andfeel" WHERE personid=2 //改 ALTER TABLE person ADD salary //增加列 DELETE FROM person WHERE name="Andfeel" //删除 * */ public class MainActivity extends Activity implements OnClickListener { private TextView textView; private MySQLiteHelper mDBHelper; private MySQLiteHelper bHelper; @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.btn__create_table).setOnClickListener( this ); findViewById(R.id.btn_delete_table).setOnClickListener( this ); findViewById(R.id.btn_alter_table).setOnClickListener( this ); findViewById(R.id.btn_insert).setOnClickListener( this ); findViewById(R.id.btn_delete).setOnClickListener( this ); findViewById(R.id.btn_update).setOnClickListener( this ); findViewById(R.id.btn_select).setOnClickListener( this ); textView = (TextView) findViewById(R.id.textView1); //创建数据库 mDBHelper = new MySQLiteHelper( this , "one.db" , null , 3 ); bHelper = new MySQLiteHelper( this , "two.db" , null , 4 ); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true ; } @Override public void onClick(View v) { switch (v.getId()) { case R.id.btn__create_table: btnCreateTable(); break ; case R.id.btn_delete_table: btnDeleteTable(); break ; case R.id.btn_alter_table: btnAlterTable(); break ; case R.id.btn_insert: btnInsert(); break ; case R.id.btn_delete: btnDelete(); break ; case R.id.btn_update: btnUpdate(); break ; case R.id.btn_select: btnSelect(); break ; default : break ; } } private void btnSelect() //查 { SQLiteDatabase db = mDBHelper.getWritableDatabase(); SQLiteDatabase db1 = bHelper.getWritableDatabase(); Cursor cursor = db.rawQuery( "SELECT * FROM person WHERE name = ?" , new String[]{ "rongqin" }); // cursor.moveToFirst(); while (cursor.moveToNext()) { int columnIndex = cursor.getColumnIndex( "name" ); String name = cursor.getString(columnIndex); int columnIndex2 = cursor.getColumnIndex( "phone" ); String phone = cursor.getString(columnIndex2); textView.setText(name + ":" + phone); } } private void btnUpdate() //改 { SQLiteDatabase db = mDBHelper.getWritableDatabase(); db.execSQL( "UPDATE person SET phone='0592xxxxxx' WHERE personid=5" ); } private void btnDelete() //删 { SQLiteDatabase db = mDBHelper.getWritableDatabase(); db.execSQL( "DELETE FROM person WHERE name='Andfeel'" ); } private void btnInsert() //增 { SQLiteDatabase db = mDBHelper.getWritableDatabase(); db.execSQL( "INSERT INTO person(name,phone) VALUES ('rongqin',1598088588)" ); } private void btnAlterTable() //扩展表 { } private void btnDeleteTable() //删除表 { } private void btnCreateTable() //创建表 { } } |
注：
1.通过以下方法可以修改数据库存储路径
SQLiteDatabase.openOrCreateDatabase(file, factory)；
context.openOrCreateDatabase(name, mode, factory)；