默认值设置为SQLite中柱 [英] setting a default value to a column in SQLite

问题描述

我有一个SQLite表，并希望与目前的默认值设置。我该怎么办呢？

I am having an SQLite table and wish to set it with a default value for time being. how can I do that?

下面是我的DatabaseHelper类code：

Below is my DatabaseHelper class code:

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHelper extends SQLiteOpenHelper {

    private static final String DATABASE_NAME="iFall.db";
    public static final String TIME="time";
    //public static final String STATUS="status";
    //public static final String MINES="loadmines";
    //public static final String OPENTILE="openTile";

    public DatabaseHelper(Context context)
    {
        super(context,DATABASE_NAME,null,1);
    }
    @Override
    public void onCreate(SQLiteDatabase arg0) {
        // TODO Auto-generated method stub
        //CREATE TABLE minesweeper(_id INTEGER PRIMARY KEY AUTOINCREMENT,userId TEXT
        arg0.execSQL("CREATE TABLE finalP(_id INTEGER PRIMARY KEY AUTOINCREMENT,time TEXT);");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS finalP");
        onCreate(db);
    }

}

我要指定一个默认值说50列时间。

I want to assign a default value say 50 to the column time.

推荐答案

我相信你可以做到这一点：

I believe you can do this:

arg0.execSQL("CREATE TABLE finalP(_id INTEGER PRIMARY KEY AUTOINCREMENT,time TEXT DEFAULT \'50\');");

和它应该很好地工作。

查看源码文档列约束。 <一href="http://www.sqlite.org/syntaxdiagrams.html#column-constraint">http://www.sqlite.org/syntaxdiagrams.html#column-constraint

See the sqlite docs for column constraints. http://www.sqlite.org/syntaxdiagrams.html#column-constraint

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