Question

我在我的应用中隔离了某些代码行，并找出了创建错误的代码行。创建错误的代码行在我的Main类中：

 Cursor c=handler.returnData(name);

此方法导致我的SQLite数据库的查询方法。我的SQLite数据库类的代码（我的returnData a.k.a.我的查询方法在底部）：

 public class DataHandler {
public static final String PRIORITY="priority";
public static final String LEASTHOURS="leastHours";
public static final String LEASTMINUTES="leastMinutes";
public static final String EXACTHOURS="exactHours";
public static final String EXACTMINUTES="exactMinutes";
public static final String SETHOURS="setHours";
public static final String SETMINUTES="setMinutes";
public static final String SETAMPM="setAmPm";
public static final String ACTIVITYNAME="activityName";
public static final String TABLE_NAME="mytable";
public static final String DATA_BASE_NAME="mydatabase";
public static final int DATABASE_VERSION=1;
public static final String TABLE_CREATE="create table mytable(priority INTEGER not null,"
        + "leastHours INTEGER not null,leastMinutes INTEGER not null,exactHours INTEGER not null"
        + ",exactMinutes INTEGER not null,setHours INTEGER not null,setMinutes INTEGER not null"
        + ",setAmPm text not null,activityName text not null);";

DataBaseHelper dbhelper;
Context ctx;
SQLiteDatabase db;
public DataHandler(Context ctx)
{
    this.ctx=ctx;
    dbhelper=new DataBaseHelper(ctx);
}

private static class DataBaseHelper extends SQLiteOpenHelper
{

    public DataBaseHelper(Context ctx){

        super(ctx,DATA_BASE_NAME,null,DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        try{
        db.execSQL(TABLE_CREATE);
        }
        catch(RuntimeException e)
        {
            e.printStackTrace();
        }

    }


    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        db.execSQL("DROP TABLE IF EXISTS mytable");
        onCreate(db);
    }

}

public DataHandler open()
{
    db=dbhelper.getWritableDatabase();
    return this;
}

public void close()
{
    dbhelper.close();
}

public long insertData(int priority, int leastHours,int leastMinutes,int exactHours,
        int exactMinutes,int setHours ,int setMinutes,String setAmPm,String activityName)
{
    ContentValues content=new ContentValues();
    content.put(PRIORITY, priority);
    content.put(LEASTHOURS, leastHours);
    content.put(LEASTMINUTES, leastMinutes);
    content.put(EXACTHOURS, exactHours);
    content.put(EXACTMINUTES, exactMinutes);
    content.put(SETHOURS, setHours);
    content.put(SETMINUTES, setMinutes);
    content.put(SETAMPM, setAmPm);
    content.put(ACTIVITYNAME, activityName);
    return db.insertOrThrow(TABLE_NAME, null, content);
}

public Cursor returnData(String title)
{
    return db.query(TABLE_NAME, new String[]{PRIORITY,LEASTHOURS,LEASTMINUTES,
            EXACTHOURS,EXACTMINUTES,SETHOURS,SETMINUTES,SETAMPM,ACTIVITYNAME},
            "activityName LIKE"+'%'+title+'%', null, null, null,null);
}


 }

日志猫：

 07-28 09:15:07.589: I/Adreno200-EGLSUB(29220): <ConfigWindowMatch:2136>: Format RGBA_8888.
 07-28 09:15:07.609: E/(29220): <s3dReadConfigFile:75>: Can't open file for reading
 07-28 09:15:07.609: E/(29220): <s3dReadConfigFile:75>: Can't open file for reading
 07-28 09:15:10.722: D/AbsListView(29220): Get MotionRecognitionManager
 07-28 09:15:10.843: I/Adreno200-EGLSUB(29220): <ConfigWindowMatch:2136>: Format RGBA_8888.
 07-28 09:15:10.993: E/SpannableStringBuilder(29220): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
 07-28 09:15:11.003: E/SpannableStringBuilder(29220): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
 07-28 09:15:11.744: E/SensorManager(29220): thread start
 07-28 09:15:11.754: D/SensorManager(29220): registerListener :: handle = 1  name= BMA250 Acceleration Sensor delay= 200000 Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,)--ef+8
 07-28 09:15:11.794: E/SpannableStringBuilder(29220): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
 07-28 09:15:11.794: E/SpannableStringBuilder(29220): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
 07-28 09:15:19.742: E/SQLiteLog(29220): (1) near "%": syntax error
 07-28 09:15:19.742: W/dalvikvm(29220): threadid=1: thread exiting with uncaught exception (group=0x41bf4438)
 07-28 09:15:19.762: E/AndroidRuntime(29220): FATAL EXCEPTION: main
 07-28 09:15:19.762: E/AndroidRuntime(29220): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.daymanager/com.example.daymanager.ActivityInfo}: android.database.sqlite.SQLiteException: near "%": syntax error (code 1): , while compiling: SELECT priority, leastHours, leastMinutes, exactHours, exactMinutes, setHours, setMinutes, setAmPm, activityName FROM mytable WHERE title like%car wash%
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread.access$700(ActivityThread.java:143)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.os.Handler.dispatchMessage(Handler.java:99)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.os.Looper.loop(Looper.java:137)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread.main(ActivityThread.java:4953)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at java.lang.reflect.Method.invokeNative(Native Method)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at java.lang.reflect.Method.invoke(Method.java:511)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at dalvik.system.NativeStart.main(Native Method)
 07-28 09:15:19.762: E/AndroidRuntime(29220): Caused by: android.database.sqlite.SQLiteException: near "%": syntax error (code 1): , while compiling: SELECT priority, leastHours, leastMinutes, exactHours, exactMinutes, setHours, setMinutes, setAmPm, activityName FROM mytable WHERE title like%car wash%
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1013)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:624)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at com.example.daymanager.DataHandler.returnData(DataHandler.java:99)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at com.example.daymanager.ActivityInfo.onCreate(ActivityInfo.java:57)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.Activity.performCreate(Activity.java:5160)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
 07-28 09:15:19.762: E/AndroidRuntime(29220):   ... 11 more

这是我第一次创建数据库，所以我不确定是什么问题。

Answer 1

Java中的

'%'只是一个带引号的字符文字，它会按原样附加到字符串，不带单引号。要在SQL字符串中放置引号，请将单引号放在双引号字符串文字中。在LIKE关键字之后添加一些空格。

更改

"activityName LIKE"+'%'+title+'%', null

到

"activityName LIKE '%"+title+"%'", null

或者更好的是，为了避免SQL注入，请使用

之类的参数

"activityName LIKE '%' || ? || '%'", new String[] { title }

其中||是SQL中的字符串连接运算符。

Answer 2

like关键字和参数%..%

之间需要一个空格

像这样改变你的方法，

public Cursor returnData(String title)
{
return db.query(TABLE_NAME, new String[]{PRIORITY,LEASTHOURS,LEASTMINUTES,
            EXACTHOURS,EXACTMINUTES,SETHOURS,SETMINUTES,SETAMPM,ACTIVITYNAME},
            "activityName LIKE '?'", new String[]{"%"+title+"%"}", null, null, null,null);
}

为什么我的SQLite查询方法返回错误？

2 个答案: