我正在开发应用程序，其中来自Web API的数据存储在数据库中。 我的DBHelper类：
public class DBHelper extends SQLiteOpenHelper {
public static final String DB_NAME = "LocalVenues.db";
public static final int DB_VERSION = 1;
public static final String COLUMN_ID = "_id";
public static final String TABLE_VENUES = "venues";
public static final String COLUMN_VENUE_NAME = "name";
public static final String COLUMN_RATING = "rating";
public static final String COLUMN_RATING_COLOR = "rating_color";
public static final String COLUMN_LOCATION_ID = "location_id";
public static final String COLUMN_PHOTO_ID = "photo_id";
public static final String COLUMN_PHONE = "phone";
//tips
public static final String TABLE_TIPS = "tips";
public static final String COLUMN_VENUE_ID = "venue_id";
public static final String COLUMN_TIP_TEXT = "text";
public static final String COLUMN_AUTHOR_ID = "user_id";
//locations
public static final String TABLE_LOCATIONS = "locations";
public static final String COLUMN_ADDRESS = "address";
public static final String COLUMN_LAT = "lat";
public static final String COLUMN_LNG = "lng";
//authors
public static final String TABLE_USERS = "users";
public static final String COLUMN_FIRST_NAME = "first_name";
public static final String COLUMN_LAST_NAME = "last_name";
//photos
public static final String TABLE_PHOTOS = "photos";
public static final String COLUMN_PREFIX = "prefix";
public static final String COLUMN_SUFFIX = "suffix";
private static DBHelper dbHelperInstance;
private DBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
public static synchronized DBHelper getInstance(Context context) {
if (dbHelperInstance == null) {
return dbHelperInstance = new DBHelper(context.getApplicationContext());
} else {
return dbHelperInstance;
}
}
@Override
public void onConfigure(SQLiteDatabase db) {
super.onConfigure(db);
db.setForeignKeyConstraintsEnabled(true);
}
@Override
public void onCreate(SQLiteDatabase db) {
String STM_CREATE_TABLE = "CREATE TABLE ";
String STM_PRIMARY_KEY = "PRIMARY KEY ";
String STM_FOREIGN_KEY = " FOREIGN KEY ";
String STM_REFERENCES = " REFERENCES ";
String STM_TEXT = " TEXT ";
String STM_AUTOINCREMENT = " AUTOINCREMENT, ";
String STM_TEXT_PRIMARY_KEY = STM_TEXT + STM_PRIMARY_KEY;
String STM_NOT_NULL = " NOT NULL, ";
String STM_REAL = " REAL ";
String STM_INTEGER = " INTEGER ";
String CREATE_TABLE_VENUES = STM_CREATE_TABLE + TABLE_VENUES + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_VENUE_NAME + STM_TEXT + STM_NOT_NULL +
COLUMN_RATING + STM_REAL + STM_NOT_NULL +
COLUMN_RATING_COLOR + STM_TEXT + STM_NOT_NULL +
COLUMN_LOCATION_ID + STM_INTEGER + STM_NOT_NULL +
COLUMN_PHOTO_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_PHONE + STM_TEXT + ", " +
STM_FOREIGN_KEY + "(" + COLUMN_LOCATION_ID + ")" + STM_REFERENCES + TABLE_LOCATIONS + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_PHOTO_ID + ")" + STM_REFERENCES + TABLE_PHOTOS + "(" + COLUMN_ID + ") "
+ ");";
String CREATE_TABLE_LOCATIONS = STM_CREATE_TABLE + TABLE_LOCATIONS + " ( " +
COLUMN_ID + STM_INTEGER + STM_PRIMARY_KEY + STM_AUTOINCREMENT +
COLUMN_ADDRESS + STM_TEXT + STM_NOT_NULL +
COLUMN_LAT + STM_REAL + STM_NOT_NULL +
COLUMN_LNG + STM_REAL + STM_NOT_NULL
+ ");";
String CREATE_TABLE_TIPS = STM_CREATE_TABLE + TABLE_TIPS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_VENUE_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_AUTHOR_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_TIP_TEXT + STM_TEXT + STM_NOT_NULL +
STM_FOREIGN_KEY + "(" + COLUMN_VENUE_ID + ")" + STM_REFERENCES + TABLE_VENUES + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_AUTHOR_ID + ")" + STM_REFERENCES + TABLE_USERS + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_PHOTO_ID + ")" + STM_REFERENCES + TABLE_PHOTOS + "(" + COLUMN_ID + ") "
+ ");";
String CREATE_TABLE_PHOTOS = STM_CREATE_TABLE + TABLE_PHOTOS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_PREFIX + STM_TEXT + STM_NOT_NULL +
COLUMN_SUFFIX + STM_TEXT + STM_NOT_NULL
+ ");";
String CREATE_TABLE_USERS = STM_CREATE_TABLE + TABLE_USERS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_FIRST_NAME + STM_TEXT + STM_NOT_NULL +
COLUMN_LAST_NAME + STM_TEXT + STM_NOT_NULL +
STM_FOREIGN_KEY + " ( " + COLUMN_PHOTO_ID + " ) " + STM_REFERENCES + TABLE_PHOTOS + " (" + COLUMN_ID + " ) "
+ ");";
db.execSQL(CREATE_TABLE_VENUES);
db.execSQL(CREATE_TABLE_LOCATIONS);
db.execSQL(CREATE_TABLE_TIPS);
db.execSQL(CREATE_TABLE_PHOTOS);
db.execSQL(CREATE_TABLE_USERS);
}
//The simplest implementation of onUpgrade() method
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String STM_DROP_TABLE_IF_EXISTS = "DROP TABLE IF EXISTS ";
if (oldVersion != newVersion) {
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_VENUES);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_LOCATIONS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_PHOTOS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_TIPS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_USERS);
}
}
}
我收到错误：E/SQLiteLog: (1) near ")": syntax error
因此，我有另一个子问题：有没有办法让像这样的SQLite错误提供更多信息？
答案 0 :(得分：2)
问题是这个
String STM_NOT_NULL = " NOT NULL, ";
在运行代码时，logcat输出是
CREATE TABLE locations ( _id INTEGER PRIMARY KEY AUTOINCREMENT, address TEXT NOT NULL, lat REAL NOT NULL, lng REAL NOT NULL, );
在lng REAL NOT NULL中有一个额外的逗号，）
你应该摆脱那个
进一步运行代码
Caused by: android.database.sqlite.SQLiteException: unknown column "photo_id" in foreign key definition (code 1): , while compiling: CREATE TABLE tips ( _id TEXT PRIMARY KEY , venue_id TEXT NOT NULL, user_id TEXT NOT NULL, text TEXT NOT NULL, FOREIGN KEY (venue_id) REFERENCES venues(_id), FOREIGN KEY (user_id) REFERENCES users(_id), FOREIGN KEY (photo_id) REFERENCES photos(_id) );
创建表时，查询中缺少一些列。
我不确定你的桌面结构如何。
所以我建议您通过查看logcat仔细查看您的查询。您还没有发布足够的详细信息，当您的应用崩溃时，您应该在logcat中看到这些详细信息。
以下不会崩溃。如果没有完整的崩溃日志，很难发布答案。
public class DbHelper extends SQLiteOpenHelper {
public static final String DB_NAME = "LocalVenues.db";
public static final int DB_VERSION = 1;
public static final String COLUMN_ID = "_id";
public static final String TABLE_VENUES = "venues";
public static final String COLUMN_VENUE_NAME = "name";
public static final String COLUMN_RATING = "rating";
public static final String COLUMN_RATING_COLOR = "rating_color";
public static final String COLUMN_LOCATION_ID = "location_id";
public static final String COLUMN_PHOTO_ID = "photo_id";
public static final String COLUMN_PHONE = "phone";
//tips
public static final String TABLE_TIPS = "tips";
public static final String COLUMN_VENUE_ID = "venue_id";
public static final String COLUMN_TIP_TEXT = "text";
public static final String COLUMN_AUTHOR_ID = "user_id";
//locations
public static final String TABLE_LOCATIONS = "locations";
public static final String COLUMN_ADDRESS = "address";
public static final String COLUMN_LAT = "lat";
public static final String COLUMN_LNG = "lng";
//authors
public static final String TABLE_USERS = "users";
public static final String COLUMN_FIRST_NAME = "first_name";
public static final String COLUMN_LAST_NAME = "last_name";
//photos
public static final String TABLE_PHOTOS = "photos";
public static final String COLUMN_PREFIX = "prefix";
public static final String COLUMN_SUFFIX = "suffix";
private static DbHelper dbHelperInstance;
public DbHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
public static synchronized DbHelper getInstance(Context context) {
if (dbHelperInstance == null) {
return dbHelperInstance = new DbHelper(context.getApplicationContext());
} else {
return dbHelperInstance;
}
}
@Override
public void onConfigure(SQLiteDatabase db) {
super.onConfigure(db);
db.setForeignKeyConstraintsEnabled(true);
}
@Override
public void onCreate(SQLiteDatabase db) {
String STM_CREATE_TABLE = "CREATE TABLE ";
String STM_PRIMARY_KEY = "PRIMARY KEY ";
String STM_FOREIGN_KEY = " FOREIGN KEY ";
String STM_REFERENCES = " REFERENCES ";
String STM_TEXT = " TEXT ";
String STM_AUTOINCREMENT = " AUTOINCREMENT, ";
String STM_TEXT_PRIMARY_KEY = STM_TEXT + STM_PRIMARY_KEY;
String STM_NOT_NULL = " NOT NULL, ";
String STM_REAL = " REAL ";
String STM_INTEGER = " INTEGER ";
String CREATE_TABLE_VENUES = STM_CREATE_TABLE + TABLE_VENUES + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_VENUE_NAME + STM_TEXT + STM_NOT_NULL +
COLUMN_RATING + STM_REAL + STM_NOT_NULL +
COLUMN_RATING_COLOR + STM_TEXT + STM_NOT_NULL +
COLUMN_LOCATION_ID + STM_INTEGER + STM_NOT_NULL +
COLUMN_PHOTO_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_PHONE + STM_TEXT + ", " +
STM_FOREIGN_KEY + "(" + COLUMN_LOCATION_ID + ")" + STM_REFERENCES + TABLE_LOCATIONS + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_PHOTO_ID + ")" + STM_REFERENCES + TABLE_PHOTOS + "(" + COLUMN_ID + ") "
+ ");";
String CREATE_TABLE_LOCATIONS = STM_CREATE_TABLE + TABLE_LOCATIONS + " ( " +
COLUMN_ID + STM_INTEGER + STM_PRIMARY_KEY + STM_AUTOINCREMENT +
COLUMN_ADDRESS + STM_TEXT + STM_NOT_NULL +
COLUMN_LAT + STM_REAL + STM_NOT_NULL +
COLUMN_LNG + STM_REAL + "NOT NULL"
+ ");";
String CREATE_TABLE_PHOTOS = STM_CREATE_TABLE + TABLE_PHOTOS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_PREFIX + STM_TEXT + STM_NOT_NULL +
COLUMN_SUFFIX + STM_TEXT + "NOT NUll"
+ ");";
String CREATE_TABLE_USERS = STM_CREATE_TABLE + TABLE_USERS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_PHOTO_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_FIRST_NAME + STM_TEXT + STM_NOT_NULL +
COLUMN_LAST_NAME + STM_TEXT + STM_NOT_NULL +
STM_FOREIGN_KEY + " ( " + COLUMN_PHOTO_ID + " ) " + STM_REFERENCES + TABLE_PHOTOS + " (" + COLUMN_ID + " ) "
+ ");";
String CREATE_TABLE_TIPS = STM_CREATE_TABLE + TABLE_TIPS + " ( " +
COLUMN_ID + STM_TEXT_PRIMARY_KEY + ", " +
COLUMN_PHOTO_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_VENUE_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_AUTHOR_ID + STM_TEXT + STM_NOT_NULL +
COLUMN_TIP_TEXT + STM_TEXT + STM_NOT_NULL +
STM_FOREIGN_KEY + "(" + COLUMN_VENUE_ID + ")" + STM_REFERENCES + TABLE_VENUES + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_AUTHOR_ID + ")" + STM_REFERENCES + TABLE_USERS + "(" + COLUMN_ID + "), " +
STM_FOREIGN_KEY + "(" + COLUMN_PHOTO_ID + ")" + STM_REFERENCES + TABLE_PHOTOS + "(" + COLUMN_ID + ") "
+ ");";
db.execSQL(CREATE_TABLE_VENUES);
db.execSQL(CREATE_TABLE_LOCATIONS);
db.execSQL(CREATE_TABLE_PHOTOS);
db.execSQL(CREATE_TABLE_USERS);
db.execSQL(CREATE_TABLE_TIPS);
}
//The simplest implementation of onUpgrade() method
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String STM_DROP_TABLE_IF_EXISTS = "DROP TABLE IF EXISTS ";
if (oldVersion != newVersion) {
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_VENUES);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_LOCATIONS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_PHOTOS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_TIPS);
db.execSQL(STM_DROP_TABLE_IF_EXISTS + TABLE_USERS);
}
}
}
答案 1 :(得分：1)
一个突出的问题是你正在使用的CREATE_TABLE_LOCATIONS字符串STM_NOT_NULL在关闭括号之前有一个逗号。这导致, lng REAL NOT NULL,); SQL语法 - 并且无效。这可能是你遇到的问题之一。您应该将所有最终字符串打印到LogCat（或在调试时查看它们）以确保格式正确。