安卓SQLite常見錯誤

標籤：

利用閑時寫了一個簡單的Sql語句操作SQLite資料庫，在用SimpleCursorAdapter時出了一個異常好久都沒解決

Process: com.example.chunchuner.usesqltest405, PID: 31206
java.lang.IllegalArgumentException: column ‘_id‘ does not exist

 

通過一系列尋找資料才發現

//使用SimpleCursorAdapter封裝Cursor時候Cursor要求底層資料庫的主鍵列的列名必須為_id
//否則會出現java.lang.IllegalArgumentException異常

代碼如下：

package com.example.nanchen.usesqltest405;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteException;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.CursorAdapter;import android.widget.EditText;import android.widget.ListView;import android.widget.SimpleCursorAdapter;public class MainActivity extends AppCompatActivity {    private Button insert;    private EditText textView_title,textView_content;    private SQLiteDatabase db;    private ListView listView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //建立或者開啟資料庫（此處需要使用絕對路徑）        db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()+"/my.db3",null);        insert = (Button) findViewById(R.id.insert);        listView = (ListView) findViewById(R.id.listView);        textView_title = (EditText) findViewById(R.id.title_text);        textView_content = (EditText) findViewById(R.id.content);        insert.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String title = textView_title.getText().toString();                String content = textView_content.getText().toString();                try {                    insertData(db, title, content);                }catch (SQLiteException e){                    //執行建立資料庫表                    db.execSQL("create table news_inf(_id integer primary key autoincrement, " +                            "news_title varchar2,news_content varchar2)");                    insertData(db, title, content);                }                Cursor cursor = db.rawQuery("select * from news_inf", null);                inflateList(cursor);            }        });    }    private void insertData(SQLiteDatabase db,String title,String content){        db.execSQL("insert into news_inf values(null,?,?)", new String[]{title, content});    }    private void inflateList(Cursor cursor){        //填充SimpleCursorAdapter        //使用SimpleCursorAdapter封裝Cursor時候Cursor要求底層資料庫的主鍵列的列名必須為_id        //否則會出現java.lang.IllegalArgumentException異常        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,                android.R.layout.simple_list_item_1,cursor,                new String[]{"news_title","news_content"},                new int[]{R.id.title_text,R.id.content},                CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);        //顯示資料        listView.setAdapter(adapter);    }    @Override    protected void onDestroy() {        super.onDestroy();        //退出程式時關閉SQLiteDataBase        if (db != null && db.isOpen()){            db.close();        }    }}

　　

安卓SQLite常見錯誤