Question

我使用Android的SQLite存储选项来存储一些书的参考。表已创建，但在执行Insert语句时会出错。

这是查询字符串：

writeableDatabase.execSQL("INSERT INTO " + BookSave.TABLE_NAME +
                                " VALUES( " + book.getTitle().toString() +
                                "," + book.getAuthor().toString() + ","
                                + book.getPathOfCover().toString() + " );");

这是logcat：

near "Devices": syntax error
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime: FATAL EXCEPTION: Thread-2698
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime: Process: dreamnyc.myapplication, PID: 23973
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime: android.database.sqlite.SQLiteException: near "Devices": syntax error (code 1): , while compiling: INSERT INTO book VALUES( Electronic Devices & Circuits,Jacob Millman & Christos C. Halkias,/storage/emulated/0/Android/data/dreamnyc.myapplication/files/MillmanHalkias-ElectronicDevicesCircuits/OEBPS/images/leaf-image0000.jpg );
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:891)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:502)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1674)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1605)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at dreamnyc.myapplication.MainActivity$2.run(MainActivity.java:189)
02-27 19:21:04.555 23973-24058/dreamnyc.myapplication E/AndroidRuntime:     at java.lang.Thread.run(Thread.java:818)

Answer 1

问题是，如果值类型为varchar：

，则需要围绕值引用

writeableDatabase.execSQL("INSERT INTO " + BookSave.TABLE_NAME +
                                " VALUES( '" + book.getTitle().toString() +"'," 
                                +"'"+ book.getAuthor().toString() + "',"
                                +"'"+ book.getPathOfCover().toString() + "');");

真正的问题是你应该使用参数化查询来避免这些类型的错误，但也要防止sql注入。

例如：

ContentValues values = new ContentValues();
values.put(KEY_TITLE, book.getTitle().toString());
values.put(KEY_AUTHOR, book.getAuthor().toString());
values.put(KEY_PATH_COVER, book.getPathOfCover().toString());
writeableDatabase.insert(TABLE_NAME, null, values);

KEY_是列名称作为字符串

SQLite中的语法错误（插入语句）

1 个答案: