Use [`ContentValues.putNull(java.lang.String)`][1]:

&lt;!-- language-all: lang-java --&gt;

    ContentValues args = new ContentValues();
    args.putNull(KEY_RISK_AMOUNT);


  [1]: http://developer.android.com/reference/android/content/ContentValues.html#putNull%28java.lang.String%29

How can I split a string by a delimiter, but not if it is escaped? For example, I have a string:

    1|2\|2|3\\|4\\\|4

The delimiter is `|` and an escaped delimiter is `\|`. Furthermore I want to ignore escaped backslashes, so in `\\|` the `|` would still be a delimiter.

So with the above string the result should be:

    [0] =&gt; 1
    [1] =&gt; 2\|2
    [2] =&gt; 3\\
    [3] =&gt; 4\\\|4

Split string by delimiter, but not if it is escaped

I have a question. Is it possible to call generic method using reflection in .NET?
I tried the following code 

    var service = new ServiceClass();
    Type serviceType = service.GetType();
    MethodInfo method = serviceType.GetMethod(&quot;Method1&quot;, new Type[]{});
    method.MakeGenericMethod(typeof(SomeClass));
    var result = method.Invoke(service, null);

But it throws the following exception &quot;Late bound operations cannot be performed on types or methods for which ContainsGenericParameters is true.&quot;

Calling generic method using reflection in .NET

For example, I want to do the following on a database update.

Is there a constant I can use instead of `null`, which won&#39;t compile if I use it like:

&lt;!-- language-all: lang-java --&gt;

    ContentValues args = new ContentValues();
    args.put(KEY_RISK_AMOUNT, null); // what constant do I use instead of null?



How do I update an android sqlite database column value to null using ContentValues?

For example, I want to do the following on a database update.
Is there a constant I can use instead of <code>null</code>, which won't compile if I use it like:

<pre><code class="hljs language-ini">ContentValues args = new ContentValues();
args.put(KEY_RISK_AMOUNT, null); // what constant do I use instead of null?
</code></pre>

I am developing an application that has SQLite database to store personal information that must be protected. What are some ways of protecting these personal data? An APK can easily be de-compiled completely, so how can we secure an APK? Additionally, how can a database of a mobile application be protected?


How to make apk Secure. Protecting from Decompile

    URL url = new URL(&quot;http://download.thinkbroadband.com/20MB.zip&quot;);
    
    URLConnection connection = url.openConnection();
    File fileThatExists = new File(path); 
    OutputStream output = new FileOutputStream(path, true);
    connection.setRequestProperty(&quot;Range&quot;, &quot;bytes=&quot; + fileThatExists.length() + &quot;-&quot;);
    
    connection.connect();
    
    int lenghtOfFile = connection.getContentLength();
    
    InputStream input = new BufferedInputStream(url.openStream());
    byte data[] = new byte[1024];
    
    long total = 0;
    
    while ((count = input.read(data)) != -1) {
        total += count;
    
        output.write(data, 0 , count);
    }

in this code I try to resume download. Target file is 20MB. But when I stop download on 10mb, then contunue, I get file with filesize 30MB. It seems that it continue writing to file, but cant partly download from server. Wget -c works great with this file. How can I resume file download?

Resume http file download in java

I have the following menu layout in my Android app:


    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;menu xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
        &lt;item android:id=&quot;@+id/item1&quot; 
              android:titleCondensed=&quot;Options&quot;
	          android:title=&quot;Highlight Options&quot; 
              android:icon=&quot;@android:drawable/ic_menu_preferences&quot; /&gt;

       &lt;item android:id=&quot;@+id/item2&quot; 
             android:titleCondensed=&quot;Persist&quot;
	         android:title=&quot;Persist&quot; 
             android:icon=&quot;@android:drawable/ic_menu_preferences&quot; 
             android:checkable=&quot;true&quot; /&gt;
    &lt;/menu&gt;

My problem is that the second menu item doesn&#39;t appear to be &quot;checkable&quot; when I run my app in the Android emulator. There should be a green tick about the item, right? To indicate that its checkable. 

Am I doing something wrong? 




Android Checkable Menu Item

I have a variable in my code say it is &quot;status&quot;. 

I want to display some text in the application depending on this variable value. This has to be done with a specific time delay.

It&#39;s like,

* Check status variable value

* Display some text

* Wait for 10 seconds

* Check status variable value

* Display some text

* Wait for 15 seconds

and so on. The time delay may vary and it is set once the text is displayed.

I have tried `Thread.sleep(time delay)` and it failed. Any better way to get this done?

Repeat a task with a time delay?

I&#39;m trying to build a simple Android application using NDK.
Here are the contents of my Android.mk

    LOCAL_PATH := $(call my-dir)  
      
    include $(CLEAR_VARS)  
      
    LOCAL_LDLIBS := -llog  
      
    LOCAL_MODULE    := myNDK
    LOCAL_SRC_FILES := native.c
      
    include $(BUILD_SHARED_LIBRARY)

And when I&#39;m running ndk-build I get:

&gt; make: *** No rule to make target
&gt; `&#39;/native.c&#39;, needed by
&gt; `&#39;/Users/ivan/Documents/workspace/TestNDK/obj/local/armeabi/objs/myNDK/native.o&#39;.
&gt; Stop.

So the problem is obviously that make is searching the source files in the root directory and if I copy native.c to my root folder everything works perfectly.

The question is: what should I specify in my Android.mk to set the LOCAL_PATH to my working jni folder.

Android NDK: No rule to make target

Using postgres 8.4,  My goal is to update existing table:

    CREATE TABLE public.dummy
    (
      address_id SERIAL,
      addr1 character(40),
      addr2 character(40),
      city character(25),
      state character(2),
      zip character(5),
      customer boolean,
      supplier boolean,
      partner boolean
      
    )
    WITH (
      OIDS=FALSE
    );

Initially i tested my query using insert statement:

    insert into address customer,supplier,partner
    SELECT  
    	case when cust.addr1 is not null then TRUE else FALSE end customer, 
    	case when suppl.addr1 is not null then TRUE else FALSE end supplier,
    	case when partn.addr1 is not null then TRUE else FALSE end partner
    from (
    	SELECT *
    		from address) pa
    	left outer join cust_original cust
    		on (pa.addr1=cust.addr1 and pa.addr2=cust.addr2 and pa.city=cust.city 
    			and pa.state=cust.state and substring(cust.zip,1,5) = pa.zip  )
    	left outer join supp_original suppl 
    		on (pa.addr1=suppl.addr1 and pa.addr2=suppl.addr2 and pa.city=suppl.city 
    			    and pa.state=suppl.state and pa.zip = substring(suppl.zip,1,5))
    	left outer join partner_original partn
    		on (pa.addr1=partn.addr1 and pa.addr2=partn.addr2 and pa.city=partn.city
    			      and pa.state=partn.state and pa.zip = substring(partn.zip,1,5) )
    where pa.address_id = address_id

being Newbie I&#39;m failing converting to update statement ie., updating existing rows with values returned by select statement.
Any help is highly appreciated.

updating table rows in postgres using subquery

I have very simple question but i did&#39;t get any simple code to exit from SP using Mysql.
Can anyone share with me how to do that?

    CREATE PROCEDURE SP_Reporting(IN tablename VARCHAR(20))
    BEGIN
         IF tablename IS NULL THEN
              #Exit this stored procedure here
         END IF;
    
         #proceed the code
    END;

Mysql - How to quit/exit from stored procedure

I&#39;m using Postgres and cannot manage to get the last record of my table:

     my_query = client.query(&quot;SELECT timestamp,value,card from my_table&quot;);

How can I do that knowning that timestamp is a unique identifier of the record ?

Get last record of a table in Postgres

Is there any possibility to use an &quot;after update&quot; trigger only in the case the data has been REALLY changed.
I know of &quot;NEW and OLD&quot;. But when using them I&#39;m only able to compare columns.
For example &quot;NEW.count &lt;&gt; OLD.count&quot;.

But I want something like: run trigger if &quot;NEW &lt;&gt; OLD&quot;

An Example:

    create table foo (a INT, b INT);
    create table bar (a INT, b INT);

    INSERT INTO foo VALUES(1,1);
    INSERT INTO foo VALUES(2,2);
    INSERT INTO foo VALUES(3,3);

    CREATE TRIGGER ins_sum
        AFTER UPDATE ON foo
        FOR EACH ROW
        INSERT INTO bar VALUES(NEW.a, NEW.b);

    UPDATE foo SET b = 3 WHERE a=3;
    Query OK, 0 rows affected (0.00 sec)
    Rows matched: 1  Changed: 0  Warnings: 0


    select * from bar;
    +------+------+
    | a    | b    |
    +------+------+
    |    3 |    3 |
    +------+------+

The point is, there was an update, but **nothing has changed**.
But the trigger ran anyway. IMHO there should be a way it doesn&#39;t.

I know that I could have used 

&gt; IF NOW.b &lt;&gt; OLD.b

for this example.

BUT imagine a large table with changing columns.
You have to compare every column and if the database changes you have to adjust the trigger.
AND it doesn&#39;t &quot;feel&quot; good to compare every column of the row hardcoded :)

**Addition**

As you can see on the line 

&gt; Rows matched: 1  Changed: 0  Warnings: 0

MySQL knows that the line didn&#39;t change. But it doesn&#39;t share this knowledge with the trigger.
A trigger like &quot;AFTER REAL UPDATE&quot; or something like this would be cool.


MySQL Trigger after update only if row has changed

Is it possible to copy data from column A to column B for all records in a table in SQL?


How can I copy data from one column to another in the same table?

is there any easy way to change the database from mysql to mongoDB ?

or better any one suggest me good tutorial do it 

converting database from mysql to mongoDb

What is the good mechanism to store information among SQLite database and Shared Preferences?

Why use shared preferences? Why use sqlite? I tried to find the difference between them, and which is the better mechanism for data storing, but I am unable to find the appropriate answer on Google. Please help me with example and explanations.



Pros and Cons of SQLite and Shared Preferences

What&#39;s the best separator/delimiter character(s) for a plaintext db file?

I considered using `|`, `,`, `&lt;TAB&gt;`, `;`, etc. But they all seem to be possible to break when the nearby entries have special enough characters. 

So, the experienced database users, what delimiter character(s) do you suggest to use?

What&#39;s the best separator/delimiter character(s) for a plaintext db file?

We are at the beginning of a new project, and we are really wondering if we should use stored procedures in MySQL or not.

We would use the stored procedures only to insert and update business model entities. There are several tables which represent a model entity, and we would abstract it in those stored procedures insert/update.

On the other hand, we can call insert and update from the Model layer but not in MySQL but in PHP.

In your experience, **Which is the best option? advantages and disadvantages of both approaches. Which is the fastest one in terms of high performance?**

PS: It is is a web project with mostly read and high performance is the most important requisite.



MySQL stored procedures use them or not to use them

How to retrieve inserted id after inserting row in SQLite using Python? I have table like this:

    id INT AUTOINCREMENT PRIMARY KEY,
    username VARCHAR(50),
    password VARCHAR(50)

I insert a new row with example data `username=&quot;test&quot;` and `password=&quot;test&quot;`. How do I retrieve the generated id in a transaction safe way? This is for a website solution, where two people may be inserting data at the same time. I know I can get the last read row, but I don&#39;t think that is transaction safe. Can somebody give me some advice?

How to retrieve inserted id after inserting row in SQLite using Python?

I&#39;m completely new to [Python&#39;s sqlite3 module][1] (and SQL in general for that matter), and this just completely stumps me. The abundant lack of descriptions of [`cursor` objects][2] (rather, their necessity) also seems odd. 

This snippet of code is the preferred way of doing things:

    import sqlite3
    conn = sqlite3.connect(&quot;db.sqlite&quot;)
    c = conn.cursor()
    c.execute(&#39;&#39;&#39;insert into table &quot;users&quot; values (&quot;Jack Bauer&quot;, &quot;555-555-5555&quot;)&#39;&#39;&#39;)
    conn.commit()
    c.close()

This one isn&#39;t, even though it works just as well and without the (seemingly pointless) `cursor`:

    import sqlite3
    conn = sqlite3.connect(&quot;db.sqlite&quot;)
    conn.execute(&#39;&#39;&#39;insert into table &quot;users&quot; values (&quot;Jack Bauer&quot;, &quot;555-555-5555&quot;)&#39;&#39;&#39;)
    conn.commit()

Can anyone tell me why I need a `cursor`?
&lt;br /&gt;It just seems like pointless overhead. For every method in my script that accesses a database, I&#39;m supposed to create and destroy a `cursor`?
&lt;br /&gt;Why not just use the `connection` object?


  [1]: https://docs.python.org/3.6/library/sqlite3.html
  [2]: https://docs.python.org/3.6/library/sqlite3.html#cursor-objects

Why do you need to create a cursor when querying a sqlite database?

How do I get the row count of a query in Android using SQLite? It seems my following method does not work.

    public int getFragmentCountByMixId(int mixId) {
        int count = 0;
        SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
		
        Cursor cursor = db.rawQuery(
            &quot;select count(*) from downloadedFragement where mixId=?&quot;,
            new String[]{String.valueOf(mixId)});
        while(cursor.moveToFirst()){
            count = cursor.getInt(0);
        }
        return count;
    }    



Content Type	Original Author	Original Content on Stackoverflow
Question	steve	View Question on Stackoverflow
Solution 1 - Android	skolima	View Answer on Stackoverflow

How do I update an android sqlite database column value to null using ContentValues?

Android Problem Overview

Android Solutions

Solution 1 - Android

Calling generic method using reflection in .NET

Split string by delimiter, but not if it is escaped

Attributions