SQLite更新查询 - Android

Question

我无法在我的Android应用程序中破解一个简单的SQLite更新查询...这是查询：

int fav = 1;
Cursor c = sqliteDB.rawQuery("UPDATE "+ MyConstants.TABLE_NAME + " SET "+MyConstants.TABLE_NAME+"."+MyConstants.ISFAV+ " = "+fav+ " WHERE " +MyConstants.TABLE_NAME+"."+MyConstants.WORD_NAME+ " = \""+word_name+"\"", null);

以下是异常信息：

07-06 23:41:48.723: E/AndroidRuntime(1102): FATAL EXCEPTION: main
07-06 23:41:48.723: E/AndroidRuntime(1102): android.database.sqlite.SQLiteException: near ".": syntax error (code 1): , while compiling: UPDATE words SET words.isfavor = 1 WHERE words.word = "hello"
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1013)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:624)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
07-06 23:41:48.723: E/AndroidRuntime(1102):     at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)

- Naveen

Answer 1

您一直在不当地使用表名。应该更像这样：

int fav = 1;
Cursor c = sqliteDB.rawQuery("UPDATE "+ MyConstants.TABLE_NAME + " SET "+ MyConstants.ISFAV + " = "+fav+ " WHERE " + MyConstants.WORD_NAME + " = \""+word_name+"\"", null);

这样会给你一个更接近下面的查询结果：

UPDATE words SET isfavor = 1 WHERE word = "hello"

- HalR

Answer 2

1. UPDATE语句总是只有一个表，因此在列名前加上表名是没有意义的，也是不允许的。
2. 在SQL中，字符串需要用'括起来。 "则用于标识符，如列名；如果您尝试处理单词word，则查询将崩溃。
3. 为避免字符串格式化问题，应使用参数：

    sqliteDB.rawQuery("UPDATE ... WHERE word = ?",
                      new String[] { word_name });

- CL.