如何在android的sqlite的外键？ [英] how to create foreign key in sqlite android?

问题描述

我是新手机器人。如何创建的表的外键？下面是我的code，创造表这是playerTable和attackTable。请帮助！

I'm newbie android. How to create foreign key in the table? below is my code that create table which are playerTable and attackTable. Please help!

public void onCreate(SQLiteDatabase db) {
    // Create a database table
            String createPlayerTable = "CREATE TABLE " + TABLE_NAME
                    + " (_id INTEGER PRIMARY KEY      autoincrement," + PlayerName + " TEXT not null, "
                    + PlayerAge + " TEXT not null, "+PlayerBorn+" TEXT not null, "+PlayerWeight+" TEXT not null, "+PlayerHeight+" TEXT not null);";
            db.execSQL(createPlayerTable);

            String createAttackTable = "CREATE TABLE " + TABLE_ATTACK
                    + " (_ID INTEGER PRIMARY KEY autoincrement," + playerAttack + " TEXT not null, "
                    + playerPassing + " TEXT not null);";
            db.execSQL(createAttackTable);              

除此之外，自动增量可以从其他数字开始，如1000？我的意思是自动增量启动从1，2，3，4，等等......我想从1000，10001，1002号开始...这可能吗？

Besides that, can autoincrement start from other number such as 1000? I mean autoincrement start from 1, 2, 3, 4, and so on... i want the number start from 1000, 10001, 1002... is that possible?

推荐答案

您可以将列定义后添加外键，使用关键字FOREIGN KEY：

You can add the foreign key after the column definition, with keyword FOREIGN KEY:

例如创建一个外键表TABLE_ATTACK列playerPassing，指出playerPassing被引用表TABLE_NAME和它的列_id，你把类似下面的code后，TEXT非空：
+外键（+ playerPassing +）参考+ TABLE_NAME +（_id）

For example to create a foreign key to column playerPassing of table TABLE_ATTACK that says that playerPassing is referencing table TABLE_NAME and it's column _id, you put something like the following code after "TEXT not null" : +"FOREIGN KEY("+ playerPassing +") REFERENCES "+ TABLE_NAME + "(_id)"

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