【问题标题】:How to use insert() method about sqlite Database in android如何在android中使用关于sqlite数据库的insert()方法
【发布时间】:2023-03-22 01:02:01
【问题描述】:

这是我的代码 (MainActivity.java.OnCreate):

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //creating a database
    SQLiteDatabase sqLiteDatabase=this.openOrCreateDatabase("DB_NAME",MODE_PRIVATE,null);
    //creating a table with one column named 'column' inside of it.
    sqLiteDatabase.execSQL("CREATE TABLE IF NOT EXISTS tb_name('column'VARCHAR)");
    //creating an OnClickListener for a simple button(I havent included the activity_main.xml but I dont think that it is necessary)
    Button button=(Button)findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ContentValues contentValues=new ContentValues();
            contentValues.put("column","this item is inserted");
            sqLiteDatabase.insert("table",null,contentValues);
            long valueOfInsertion = sqLiteDatabase.insert("table",null,contentValues);
            Log.i("button","value of insertion: "+ valueOfInsertion);





        }
    });
}```

但我不断从 logcat 获得值 -1(查看我的代码的第 18 行以获取更多信息)和异常:

2021-01-16 22:33:58.162 9051-9051/com.rahgozar.d2 E/SQLiteDatabase: Error inserting column=this item is inserted
    android.database.sqlite.SQLiteException: near "table": syntax error (code 1 SQLITE_ERROR): , while compiling: INSERT INTO table(column) VALUES (?)
        at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
        at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1045)
        at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:652)
        at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:590)
        at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:61)
        at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:33)
        at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1699)
        at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1570)
        at com.rahgozar.d2.MainActivity$1.onClick(MainActivity.java:30)
        at android.view.View.performClick(View.java:7448)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
        at android.view.View.performClickInternal(View.java:7425)
        at android.view.View.access$3600(View.java:810)
        at android.view.View$PerformClick.run(View.java:28305)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

重要提示:只有当我单击按钮时才会发生异常(调用 OnClickListener);

【问题讨论】:

    标签: java android sqlite android-sqlite


    【解决方案1】:

    表的名称是 tb_name 而不是 table
    此外,将column 之类的关键字用于列名等标识符也不是一个好习惯。
    最后,SQLite 中没有 VARCHAR 数据类型。您可以使用TEXT

    所以,对于表的创建,你可以这样做:

    sqLiteDatabase.execSQL("CREATE TABLE IF NOT EXISTS tb_name(columnName TEXT)");
    

    columnName 更改为有意义的名称(不需要单引号)。

    并插入新行:

    ContentValues contentValues = new ContentValues();
    contentValues.put("columnName", "this item is inserted");
    sqLiteDatabase.insert("tb_name", null, contentValues);
    

    完成这些更改后,您可能需要从设备上卸载应用并重新运行。

    【讨论】:

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