?
一个简单的入门 Android app 示例， 学生管理系统， ?单表查询， 实习增、删、改、查， 基于：SQLiteOpenHelper
?
部分代码：SQLiteOpenHelper.java
package com.lw.db;import java.util.ArrayList;import java.util.List;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.text.TextUtils;import com.lw.main.Student;public class DBHelper extends SQLiteOpenHelper { private static DBHelper myDBHelper = null; public DBHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } public static DBHelper getDBHelper(Context context) { if(myDBHelper == null) { myDBHelper = new DBHelper(context, DBConfig.DB_NAME, null, DBConfig.DB_VERSION); } return myDBHelper; } @Override public void onCreate(SQLiteDatabase db) { String sql = "create table " + DBConfig.TABLE_STUDENT + "(_id integer primary key autoincrement, serialNo VARCHAR2(20) not null, name VARCHAR2(50) not null, sex VARCHAR2(4), age VARCHAR2(4), className VARCHAR2(50) not null)"; db.execSQL(sql); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { String sql = "DROP TABLE IF EXISTS " + DBConfig.TABLE_STUDENT; db.execSQL(sql); onCreate(db); } /*** * insert 学生信息 * @param serialNo * @param name * @param sex * @param age * @param className * @return */ public long insertStudent(String serialNo, String name, String sex, String age, String className) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues cv = new ContentValues(); cv.put("serialNo", serialNo); cv.put("name", name); cv.put("sex", sex); cv.put("age", age); cv.put("className", className); long rowId=db.insert(DBConfig.TABLE_STUDENT, null, cv); System.out.println("-----rowId-------"+rowId); return rowId; } /*** * 删除表的(所有)数据 * @param tableName */ public void clearData(String tableName) { SQLiteDatabase db = this.getReadableDatabase(); String sql = "DELETE FROM " + tableName; db.execSQL(sql); } /*** * 删除单条记录 * @param _id */ public void deleteStudent(int _id) { SQLiteDatabase db = this.getReadableDatabase(); String sql = "DELETE FROM " + DBConfig.TABLE_STUDENT + " WHERE _id=" + _id; db.execSQL(sql); } /*** * 编辑 * @param _id */ public void updateStudent(Student stu) { SQLiteDatabase db = this.getReadableDatabase(); ContentValues cv = new ContentValues(); //cv.put("serialNo", stu.getSerialNo()); cv.put("name", stu.getName()); cv.put("sex", stu.getSex()); cv.put("age", stu.getAge()); cv.put("className", stu.getClassName()); int rowId=db.update(DBConfig.TABLE_STUDENT, cv, "_id =?", new String[]{ stu.get_id() + "" }); System.out.println("-----update RowId------"+rowId); } /*** * 查询全部学生信息 * @param stu * @return */ public List<Student> queryStudents(Student stu) { List<Student> list = new ArrayList<Student>(); SQLiteDatabase db = this.getReadableDatabase(); String sql = "select * from " + DBConfig.TABLE_STUDENT; if(stu != null) { sql += " where 1=1 "; if(TextUtils.isEmpty(stu.getSerialNo()) == false) { // TODO } if(TextUtils.isEmpty(stu.getName()) == false) { sql += " and name like '%" + stu.getName() + "%'"; } } sql += " order by serialNo "; Cursor cursor = db.rawQuery(sql, null); Student info = null; while(cursor.moveToNext()) { info = new Student(); info.set_id(cursor.getInt(cursor.getColumnIndexOrThrow("_id"))); info.setSerialNo(cursor.getString(cursor.getColumnIndexOrThrow("serialNo"))); info.setName(cursor.getString(cursor.getColumnIndexOrThrow("name"))); info.setSex(cursor.getString(cursor.getColumnIndexOrThrow("sex"))); info.setAge(cursor.getString(cursor.getColumnIndexOrThrow("age"))); info.setClassName(cursor.getString(cursor.getColumnIndexOrThrow("className"))); list.add(info); } return list; } }?
?
登录界面：
?
?
信息列表：
?
?
?
新增信息：
?
?