AndroidStudioSQLite数据库增删改查简单（代码参考）

一个建表
一个执行crud操作

建表代码

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;public class DatabaseHelper extends SQLiteOpenHelper {public DatabaseHelper(Context context){super(context,"Test.db",null,1);}//第一个参数是上下文&＃xff0c;第二个参数是数据库名称&＃xff0c;//第三个参数是CursorFactory对象&＃xff0c;一般设置为null&＃xff0c;第四个参数是数据库的版本public void onCreate(SQLiteDatabase db) {db.execSQL("CREATE TABLE information(_id INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),age INTEGER)");}//创建表 表名information 表结构 自增id&＃xff0c;字符串姓名&＃xff0c;int年龄public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {Log.d("myDeBug","数据库版本已更新");}//数据库版本发生变化时调用
}


执行crud代码

import androidx.appcompat.app.AppCompatActivity;import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;import java.util.ArrayList;
import java.util.List;public class DictActivity extends AppCompatActivity {private Button insertButton,updateButton,searchButton,deleteButton;private EditText name,age;private TextView show,showAge;final DatabaseHelper dbHelper&＃61;new DatabaseHelper(DictActivity.this);&＃64;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_dict);insertButton&＃61;findViewById(R.id.btn_insert);updateButton&＃61;findViewById(R.id.btn_update);searchButton&＃61;findViewById(R.id.btn_search);deleteButton&＃61;findViewById(R.id.btn_delete);name&＃61;findViewById(R.id.name);age&＃61;findViewById(R.id.age);show&＃61;findViewById(R.id.tv_show);showAge&＃61;findViewById(R.id.tv_showAge);SQLiteDatabase db&＃61;dbHelper.getReadableDatabase();myShow();insertButton.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {SQLiteDatabase db&＃61;dbHelper.getWritableDatabase();ContentValues values&＃61;new ContentValues();values.put("name",name.getText().toString());values.put("age",age.getText().toString());long id &＃61;db.insert("information",null,values);Log.d("myDeBug","insert");myShow();db.close();name.setText(null);age.setText(null);}});updateButton.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {SQLiteDatabase db&＃61;dbHelper.getWritableDatabase();ContentValues values&＃61;new ContentValues();values.put("age",age.getText().toString());db.update("information",values,"name&＃61;?",new String[]{name.getText().toString()});myShow();db.close();Log.d("myDebug","update");name.setText(null);age.setText(null);}});searchButton.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {SQLiteDatabase db&＃61;dbHelper.getWritableDatabase();String name1&＃61;name.getText().toString();show.setText(null);if(name1.equals("")){
// show.setText("姓名");
// showAge.setText("年龄");
// Cursor cursor &＃61; db.rawQuery("select * from information",null);
//
// while (cursor.moveToNext()) {
// String newName &＃61; cursor.getString(cursor.getColumnIndex("name"));
// int newAge &＃61; cursor.getInt(cursor.getColumnIndex("age"));
// show.setText(show.getText() &＃43; "\n" &＃43; newName);
// showAge.setText(showAge.getText()&＃43;"\n" &＃43; newAge);
// }myShow();db.close();}else {show.setText("姓名");showAge.setText("年龄");Cursor cursor &＃61; db.rawQuery("select * from information where name &＃61; ? ", new String[]{name1});while (cursor.moveToNext()) {String newName &＃61; cursor.getString(cursor.getColumnIndex("name"));int newAge &＃61; cursor.getInt(cursor.getColumnIndex("age"));
// show.setText(show.getText() &＃43; "\n" &＃43; newName &＃43; "\t" &＃43; newAge);show.setText(show.getText() &＃43; "\n" &＃43; newName);showAge.setText(showAge.getText()&＃43;"\n" &＃43; newAge);}cursor.close();db.close();name.setText(null);age.setText(null);}}});deleteButton.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {SQLiteDatabase db&＃61;dbHelper.getWritableDatabase();db.delete("information","name&＃61;?",new String[]{name.getText().toString()});myShow();db.close();Log.d("myDeBug","DeleteSuccess");name.setText(null);age.setText(null);}});}public void myShow(){SQLiteDatabase db&＃61;dbHelper.getReadableDatabase();show.setText("姓名");showAge.setText("年龄");Cursor cursor &＃61; db.rawQuery("select * from information",null);while (cursor.moveToNext()) {String newName &＃61; cursor.getString(cursor.getColumnIndex("name"));int newAge &＃61; cursor.getInt(cursor.getColumnIndex("age"));show.setText(show.getText() &＃43; "\n" &＃43; newName);showAge.setText(showAge.getText()&＃43;"\n" &＃43; newAge);}cursor.close();}

界面布局

<?xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<LinearLayout xmlns:android&＃61;"http://schemas.android.com/apk/res/android"android:layout_width&＃61;"match_parent"android:layout_height&＃61;"match_parent"android:orientation&＃61;"vertical"><LinearLayoutandroid:orientation&＃61;"horizontal"android:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"><TextViewandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:text&＃61;"姓名"android:textSize&＃61;"30sp"/><EditTextandroid:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"android:hint&＃61;"请输入姓名"android:textSize&＃61;"20sp"android:id&＃61;"&＃64;&＃43;id/name"/></LinearLayout><LinearLayoutandroid:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"><TextViewandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:text&＃61;"年龄"android:textSize&＃61;"30sp"/><EditTextandroid:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"android:hint&＃61;"请输入年龄"android:textSize&＃61;"20sp"android:id&＃61;"&＃64;&＃43;id/age"/></LinearLayout><LinearLayoutandroid:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"android:orientation&＃61;"horizontal"><Buttonandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:textSize&＃61;"20sp"android:text&＃61;"插入"android:id&＃61;"&＃64;&＃43;id/btn_insert"android:textAllCaps&＃61;"false"/><Buttonandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:textSize&＃61;"20sp"android:text&＃61;"更新"android:id&＃61;"&＃64;&＃43;id/btn_update"android:textAllCaps&＃61;"false"/><Buttonandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:textSize&＃61;"20sp"android:text&＃61;"查询"android:id&＃61;"&＃64;&＃43;id/btn_search"android:textAllCaps&＃61;"false"/><Buttonandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:textSize&＃61;"20sp"android:text&＃61;"删除"android:id&＃61;"&＃64;&＃43;id/btn_delete"android:textAllCaps&＃61;"false"/></LinearLayout><LinearLayoutandroid:layout_width&＃61;"match_parent"android:layout_height&＃61;"wrap_content"android:orientation&＃61;"horizontal"><TextViewandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:id&＃61;"&＃64;&＃43;id/tv_show"android:textSize&＃61;"20sp"android:gravity&＃61;"center_horizontal"/><TextViewandroid:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:layout_weight&＃61;"1"android:id&＃61;"&＃64;&＃43;id/tv_showAge"android:textSize&＃61;"20sp"android:gravity&＃61;"center_horizontal"/>
</LinearLayout></LinearLayout>