我正在尝试使用sqlite3在android中创建表 我的开放助手就是:
public class TaskOpenHelper extends BaseOpenHelper {
public static final String TABLE_NAME = "tasks";
public static final String COL_ID = "id";
public static final String COL_USER_ID = "user_id";
public static final String COL_TITLE = "title";
public static final String COL_DATE = "date";
public static final String COL_TIME = "time";
public static final String COL_IS_DONE = "is_done";
public static final String COL_IS_IPM = "is_ipm";
public static final String COL_DESC = "desc";
public static final String COL_REGISTER_TIME = "register_time";
public static final String CREATE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_NAME +
"(" +
COL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
COL_USER_ID + " INTEGER NOT NULL," +
COL_TITLE + " TEXT NOT NULL," +
COL_DATE + " TEXT ," +
COL_TIME + " TEXT ," +
COL_IS_DONE + " INTEGER ," +
COL_IS_IPM + " INTEGER ," +
COL_DESC + " TEXT," +
COL_REGISTER_TIME + " TEXT," +
"FOREIGN KEY " + COL_USER_ID + " REFERENCES " + UserOpenHelper.TABLE_NAME + "(" + UserOpenHelper.COL_ID + ")" +
");";
public TaskOpenHelper(Context context) {
super(context, DATABASE_NAME, null, VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL(CREATE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(sqLiteDatabase);
}
但是当我在尝试创建表时运行app时,这个错误得到了确认:
Caused by: android.database.sqlite.SQLiteException: near "user_id": syntax error (code 1): , while compiling: CREATE TABLE IF NOT EXISTS tasks(id INTEGER PRIMARY KEY AUTOINCREMENT,user_id INTEGER NOT NULL,title TEXT NOT NULL,date TEXT ,time TEXT ,is_done INTEGER ,is_ipm INTEGER ,desc TEXT,register_time TEXT,FOREIGN KEY user_id REFERENCES user(Id));
这个open helper在数据源类中用于执行db
中的查询答案 0 :(得分:2)
您需要在user_id
子句的括号中加上FOREIGN KEY
:
FOREIGN KEY (user_id) REFERENCES user(Id)
整个陈述应该看起来像
CREATE TABLE IF NOT EXISTS tasks(id INTEGER PRIMARY KEY AUTOINCREMENT,
user_id INTEGER NOT NULL,
title TEXT NOT NULL,
date TEXT,
time TEXT,
is_done INTEGER,
is_ipm INTEGER,
desc TEXT,
register_time TEXT,
FOREIGN KEY user_id REFERENCES user(Id));
此外,您必须更改desc
列的名称,因为这是SQLite中的reserved word。