数据库中限制重复插入

 /**<pre name="code" class="java">

* 如果有本道题信息就更新，没有就插入 * @param info */ public void InsertOrReplace(CorrectsInfo info){ SQLiteDatabase db = openHelper.getWritableDatabase(); db.execSQL(" insert or replace into Corrects(userId, hwBatchId,studentId,techRemark,flag,imagePath,imageRPath,hwId,longTime,studentHwId,isSubmit,love) values(?,?,?,?,?,?,?,?,?,?,?,?)", new Object[]{info.getUserId(), info.getHwBatchId(),info.getStudentId(), info.getTechRemark(), info.getFlag(),info.getImagePath(),info.getImageRPath(), info.getHwId(),info.getLongTime(),info.getStudentBatchId(),info.getIsSubmit(),info.getLove()}); }

db.execSQL("CREATE TABLE IF NOT EXISTS Corrects(_id integer primary key autoincrement, userId varchar, hwBatchId varchar, studentId varchar, " +
                "techRemark varchar,flag varchar,imagePath varchar," +
                "imageRPath varchar,hwId varchar,longTime varchar <span style="color:#006600;">unique</span>,studentHwId varchar,isSubmit varchar,love varchar)");//唯一字段+unique