AUTOINCREMENT不工作 [英] AUTOINCREMENT not working

问题描述

我要创建1 predefine行中有一个表。 所以，我加入中的onCreate（）行;

I want to create a table with 1 predefine row in it. So, I am adding the row in onCreate();

以下是我的code：

private static final String CREATE_CATEGORY_TABLE = "CREATE TABLE CATEGORYTABLE (_id INTEGER PRIMARY KEY AUTOINCREMENT, category_name VARCHAR(255));";

private static final String DROP_CATEGORY_TABLE = "DROP TABLE IF EXISTS CATEGORYTABLE";

private static final String INSERT_PREDEFINED_CATEGORY = "INSERT INTO CATEGORYTABLE VALUES('Category 1');";

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        try {
            db.execSQL(DROP_CATEGORY_TABLE);
            onCreate(db);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        try {
            db.execSQL(CREATE_CATEGORY_TABLE);
            db.execSQL(INSERT_PREDEFINED_CATEGORY); <-- error on this line 
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

错误消息：

sqlite returned: error code = 1, msg = table CATEGORYTABLE has 2 columns but 1 values were supplied

Failure 1 (table CATEGORYTABLE has 2 columns but 1 values were supplied) on 0x287cb8 when preparing 'INSERT INTO CATEGORYTABLE VALUES('Home');'.

这是要在表格中插入pdefined行中的$ P $的正确方法？ 请帮帮忙！

Is this the correct way to insert a predefined row in a table? Please help!

推荐答案

该表有两列，所以你要么需要提供2个值，或指定要插入的列名。更改

The table has 2 columns so you will either need to provide 2 values, or specify the column names you want to insert to. Change

INSERT INTO CATEGORYTABLE VALUES('Category 1')

到

INSERT INTO CATEGORYTABLE VALUES(NULL, 'Category 1')

或

INSERT INTO CATEGORYTABLE(category_name) VALUES('Category 1')

有关它的价值，这也是一个不好的做法，以赶在的onCreate异常（）或 onUpgrade（） 。如果有一个问题，回调应该不会正常返回。

For what it's worth, it's also a bad practice to catch exceptions in onCreate() or onUpgrade(). If there's a problem, the callback should not return normally.

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