基础
import sqlite3# 连接到数据库
conn = sqlite3.connect('mydatabase.db')
cursor = conn.cursor()# 执行查询
cursor.execute("SELECT * FROM users")
rows = cursor.fetchall()for row in rows:print(row)# 关闭连接
conn.close()创建一个继承自 SQLiteOpenHelper 的类，这个类用于管理数据库的创建和版本更新
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;public class MyDatabaseHelper extends SQLiteOpenHelper {// 定义数据库名private static final String DATABASE_NAME = "my_database.db";// 定义数据库版本private static final int DATABASE_VERSION = 1;// 定义要创建的表名public static final String TABLE_NAME = "my_table";// 定义表中的 id 列名public static final String COLUMN_ID = "id";// 定义表中的 name 列名public static final String COLUMN_NAME = "name";// 创建表的 SQL 语句private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + " (" +COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +COLUMN_NAME + " TEXT NOT NULL);";// 构造函数，接收上下文对象public MyDatabaseHelper(Context context) {super(context, DATABASE_NAME, null, DATABASE_VERSION);}// 当数据库首次创建时调用，用于创建表@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL(CREATE_TABLE);}// 当数据库版本更新时调用，可用于升级表结构@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {// 删除旧表db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);// 重新创建表onCreate(db);}
} 查询数据
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity {private MyDatabaseHelper dbHelper;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView{"name":"GodelPlugin","parameters":{"input":"\"setContentView(R.layout.activity_main);\""}}<|FunctionExecuteEnd|><|FunctionExecuteResult|>setContentView(R.layout.activity_main);<|FunctionExecuteResultEnd|>// 创建数据库帮助类的实例dbHelper = new MyDatabaseHelper(this);// 插入一些示例数据insertData("Alice");insertData("Bob");// 查询数据queryData();}// 插入数据的方法private void insertData(String name) {// 获取可写的数据库实例SQLiteDatabase db = dbHelper.getWritableDatabase();// 插入数据的 SQL 语句String insertQuery = "INSERT INTO " + MyDatabaseHelper.TABLE_NAME + " (" + MyDatabaseHelper.COLUMN_NAME + ") VALUES ('" + name + "');";// 执行插入操作db.execSQL(insertQuery);// 关闭数据库db.close();}// 查询数据的方法private void queryData() {// 获取可读的数据库实例SQLiteDatabase db = dbHelper.getReadableDatabase();// 查询语句，这里查询表中的所有数据String selectQuery = "SELECT * FROM " + MyDatabaseHelper.TABLE_NAME;// 执行查询操作，返回一个 Cursor 对象Cursor cursor = db.rawQuery(selectQuery, null);if (cursor.moveToFirst()) {do {// 获取 id 列的值int id = cursor.getInt(cursor.getColumnIndex(MyDatabaseHelper.COLUMN_ID));// 获取 name 列的值String name = cursor.getString(cursor.getColumnIndex(MyDatabaseHelper.COLUMN_NAME));// 显示查询结果Toast.makeText(this, "ID: " + id + ", Name: " + name, Toast.LENGTH_SHORT).show();} while (cursor.moveToNext());}// 关闭游标cursor.close();// 关闭数据库db.close();}
} 搜索在sqlite查出数据
xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:padding="16dp"><EditTextandroid:id="@+id/search_edit_text"android:layout_width="match_parent"android:layout_height="wrap_content"android:hint="输入搜索关键词" /><Buttonandroid:id="@+id/search_button"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="搜索" /><TextViewandroid:id="@+id/result_text_view"android:layout_width="match_parent"android:layout_height="wrap_content"android:paddingTop="16dp" />
</LinearLayout> java
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity {private MyDatabaseHelper dbHelper;private EditText searchEditText;private TextView resultTextView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView{"name":"GodelPlugin","parameters":{"input":"\"setContentView(R.layout.activity_main);\""}}<|FunctionExecuteEnd|><|FunctionExecuteResult|>setContentView(R.layout.activity_main);<|FunctionExecuteResultEnd|>// 创建数据库帮助类的实例dbHelper = new MyDatabaseHelper(this);// 初始化输入框、按钮和结果显示文本视图searchEditText = findViewById(R.id.search_edit_text);Button searchButton = findViewById(R.id.search_button);resultTextView = findViewById(R.id.result_text_view);// 设置按钮点击事件监听器searchButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {// 获取输入框中的关键词String keyword = searchEditText.getText().toString();// 执行搜索操作searchData(keyword);}});// 插入一些示例数据insertData("Alice");insertData("Bob");}// 插入数据的方法private void insertData(String name) {// 获取可写的数据库实例SQLiteDatabase db = dbHelper.getWritableDatabase();// 插入数据的 SQL 语句String insertQuery = "INSERT INTO " + MyDatabaseHelper.TABLE_NAME + " (" + MyDatabaseHelper.COLUMN_NAME + ") VALUES ('" + name + "');";// 执行插入操作db.execSQL(insertQuery);// 关闭数据库db.close();}// 搜索数据的方法private void searchData(String keyword) {// 获取可读的数据库实例SQLiteDatabase db = dbHelper.getReadableDatabase();// 搜索语句，根据关键词搜索 name 列String selectQuery = "SELECT * FROM " + MyDatabaseHelper.TABLE_NAME + " WHERE " + MyDatabaseHelper.COLUMN_NAME + " LIKE '%" + keyword + "%'";// 执行搜索操作，返回一个 Cursor 对象Cursor cursor = db.rawQuery(selectQuery, null);StringBuilder result = new StringBuilder();if (cursor.moveToFirst()) {do {// 获取 id 列的值int id = cursor.getInt(cursor.getColumnIndex(MyDatabaseHelper.COLUMN_ID));// 获取 name 列的值String name = cursor.getString(cursor.getColumnIndex(MyDatabaseHelper.COLUMN_NAME));// 将结果添加到 StringBuilder 中result.append("ID: ").append(id).append(", Name: ").append(name).append("\n");} while (cursor.moveToNext());}// 关闭游标cursor.close();// 关闭数据库db.close();// 将搜索结果显示在文本视图中if (result.length() > 0) {resultTextView.setText(result.toString());} else {resultTextView.setText("未找到相关结果");}}
} 
