问题
I'm filling an arraylist with some cities, but one of them ("Reggio nell'Emilia") have an apostrophe in its name and when i select it in the app it crashes. Here is the code:
SQLiteDatabase db_read = db.getReadableDatabase();
city = new ArrayList<Object>();
Cursor result;
for (int i =0 ; i<region.size(); i++) {
result = db_read.rawQuery("select distinct city from merchants where region='"+region.get(i)+"' order by city ASC",null);
ArrayList<String> cities = new ArrayList<String>();
while (result.moveToNext()) {
String city = result.getString(0);
cities.add(city);
}
city.add(cities);
}
Here is the error in LogCat:
07-26 14:25:4 0.11 0: I/Timeline(155 06): Timeline: Activity_launch_request id:com.example.myapp time:1 0873122
07-26 14:25:4 0.225: E/SQLiteLog(155 06): (1) near "Emilia": syntax error
07-26 14:25:4 0.225: D/AndroidRuntime(155 06): Shutting down VM
07-26 14:25:4 0.225: W/dalvikvm(155 06): threadid=1: thread exiting with uncaught exception (group= 0x41f17ce 0)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): FATAL EXCEPTION: main
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): Process: com.example.myapp, PID: 155 06
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myapp/com.example.myapp.ListMerchant}: android.database.sqlite.SQLiteException: near "Emilia": syntax error (code 1): , while compiling: Select _id,title,phone,comune from merchants where city='Reggio nell'Emilia'
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2217)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2266)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread.access$8 0 0(ActivityThread.java:145)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:12 06)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.os.Handler.dispatchMessage(Handler.java:1 02)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.os.Looper.loop(Looper.java:136)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread.main(ActivityThread.java:5141)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at java.lang.reflect.Method.invokeNative(Native Method)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at java.lang.reflect.Method.invoke(Method.java:515)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:611)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at dalvik.system.NativeStart.main(Native Method)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): Caused by: android.database.sqlite.SQLiteException: near "Emilia": syntax error (code 1): , while compiling: Select _id,title,phone,comune from merchants where city='Reggio nell'Emilia'
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:5 0 0)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at com.example.myapp.ListMerchant.createListFromCity(ListMerchant.java:63)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at com.example.myapp.ListMerchant.onCreate(ListMerchant.java:43)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.Activity.performCreate(Activity.java:5231)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1 087)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2171)
07-26 14:25:4 0.24 0: E/AndroidRuntime(155 06): ... 11 more
I tried to use this hint:
String city = result.getString(0);
city = city.replace("'", "''");
and it fixes the error, but i get name with double apostrophe:
Do you know a better solution? Thank you in advance.
回答1:
Using parameters eliminates such formatting problems:
result = db_read.rawQuery("select ... where region = ? ...",
new String[] { region.get(i) });
回答2:
You should make use of SqliteQueryBuilder to make a safe query:
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
// Set the table
queryBuilder.setTables('Table_Name');
SQLiteDatabase db = database.getWritableDatabase();
Cursor cursor = queryBuilder.query(db, projection, selection,
selectionArgs, null, null, sortOrder);
Good luck.
Edited:
Also there is a util method in 'DatabaseUtils` class in andorid the help you to scape unwanted characters:
value = DatabaseUtils.sqlEscapeString(value);
回答3:
I finally solved the problem using the hint (that one described in my question) in another part of the code (it was used as extra in another activity).
来源：https://stackoverflow.com/questions/25365651/how-to-handle-word-with-apostrophe