You have to use UPDATE instead of INSERT:

- [UPDATE Syntax][1]

**For Example:**

    UPDATE table1 SET col_a=&#39;k1&#39;, col_b=&#39;foo&#39; WHERE key_col=&#39;1&#39;;
    UPDATE table1 SET col_a=&#39;k2&#39;, col_b=&#39;bar&#39; WHERE key_col=&#39;2&#39;;

  [1]: http://dev.mysql.com/doc/refman/5.0/en/update.html

    UPDATE table1 SET col_a = &#39;newvalue&#39;

Add a `WHERE` condition if you want to only update some of the rows.

This is what I did for bulk update:

    UPDATE tableName SET isDeleted = 1 where columnName in (&#39;430903GW4j683537882&#39;,&#39;430903GW4j667075431&#39;,&#39;430903GW4j658444015&#39;)

if you want to fill all the column: 

    update &#39;column&#39; set &#39;info&#39; where keyID!=0;

If you want to update data you should use `UPDATE` command instead of `INSERT`

What are the best options for performing **Web Scraping of a not currently open tab from within a Google Chrome Extension** with JavaScript and whatever more technologies are available. **Other JavaScript-libraries are also accepted.**

**The important thing is to mask the scraping to behave like a normal web-request**. No indications of AJAX or XMLHttpRequest, like `X-Requested-With: XMLHttpRequest` or `Origin`.

The scraped content must be accessible from JavaScript for further manipulation and presentation within the extension, most probably as a string.

Are there any hooks in any WebKit/Chrome-specific API:s that can be used to make a normal web-request and get the results for manipulation?

    var pageContent = getPageContent(url); // TODO: Implement
    var items = $(pageContent).find(&#39;.item&#39;);
    // Display items with further selections

***Bonus-points to make this work from a local file on disk***, for initial debugging. But if that is the only point is stopping a solution, then disregard the bonus-points.

Web Scraping in a Google Chrome Extension (JavaScript + Chrome APIs)

I have many JavaScript objects in my application, something like:

    function Person(age) {
        this.age = age;
        this.isOld = function (){
            return this.age &gt; 60;
        }
    }
    // before serialize, ok
    var p1 = new Person(77);
    alert(&quot;Is old: &quot; + p1.isOld());
    
    // after, got error Object #&lt;Object&gt; has no method &#39;isOld&#39;
    var serialize = JSON.stringify(p1);
    var _p1 = JSON.parse(serialize);
    alert(&quot;Is old: &quot; + _p1.isOld());

See in [JS Fiddle][1].


My question is: is there a best practice/pattern/tip to recover my object in same type it was before serialization (instances of class Person, in this case)?

Requirements that I have:

 - Optimize disk usage: I have a big tree of objects in memory. So, I don&#39;t want to store functions.
 - Solution can use jQuery and another library to serialize/unserialize.

  [1]: http://jsfiddle.net/8FQzm/1/

Best way to serialize/unserialize objects in JavaScript?

I have a table `table1` with three columns and a bunch of rows:


    [key_col|col_a|col_b]

I want to update col_a with a set of values (i.e. leaving `col_b` unchanged), something like this:

    INSERT INTO table1 AS t1 (key_col, col_a) VALUES (&quot;k1&quot;, &quot;foo&quot;), (&quot;k2&quot;, &quot;bar&quot;);

&lt;br&gt;
But it doesn&#39;t work, how do I do this?


Update a column in MySQL

I have a table <code>table1</code> with three columns and a bunch of rows:
<pre><code class="hljs language-csharp">[key_col|col_a|col_b]
</code></pre>
I want to update col_a with a set of values (i.e. leaving <code>col_b</code> unchanged), something like this:
<pre><code class="hljs language-sql">INSERT INTO table1 AS t1 (key_col, col_a) VALUES ("k1", "foo"), ("k2", "bar");
</code></pre>
 
But it doesn't work, how do I do this?

I have a select query where I am trying to search strings for multiple patterns

    LIKE (&#39;%this%&#39; or &#39;%that%&#39; ) and something=else
Returns zero results

However 

    LIKE &#39;%this%&#39; and something=else
returns results
and 

    LIKE &#39;%that%&#39; and something=else
returns result

Is it possible to get all my results into one query?  If a string matches both, how will it handle that?

&#39;LIKE (&#39;%this%&#39; OR &#39;%that%&#39;) and something=else&#39; not working

I have two columns in a row: `min_value`, `max_value`. Is there a way to do a select like:

    SELECT RAND(`min_v`, `max_v`) `foo` [..]

I do realize that `RAND` does a different thing; the closest I came up (with help) is `(RAND() * (max-min))+min`, though it will produce a float number, which I&#39;d need then to ROUND() and this is just completely wrong.

Unless anyone can suggest an alternative (which would be very useful), I will go PHP way.

MySQL get a random value between two values

I want retrieve the id of a inserted row in the database, but I don&#39;t know how to do this.

I tried to return using the SQL clause `RETURNING id`, but not works.

How I can return the id after the insertion of a row?

Using Prepared Statement, how I return the id of the inserted row?

I have this stored procedure. How can I run this for example with intervals of 5 seconds? Like a routine for eliminate data with a time-stamp older than one day?

    DROP PROCEDURE IF EXISTS `delete_rows_links` 
    GO
    
    CREATE PROCEDURE delete_rows_links
    BEGIN 
    
        DELETE activation_link
        FROM activation_link_password_reset
        WHERE  TIMESTAMPDIFF(DAY, `time`, NOW()) &lt; 1 ; 
    
    END 
    
    GO


How to schedule a stored procedure in MySQL

i have a table like this:

    name    date         time
    tom | 2011-07-04 | 01:09:52
    tom | 2011-07-04 | 01:09:52
    mad | 2011-07-04 | 02:10:53
    mad | 2009-06-03 | 00:01:01

i want oldest name first: 

    SELECT * 
    ORDER BY date ASC, time ASC 
    GROUP BY name

(-&gt;doesn&#39;t work!)

now it should give me first mad(has earlier date) then tom

but with `GROUP BY name ORDER BY date ASC, time ASC` gives me the newer mad first because it groups before it sorts!

again: the problem is that i can&#39;t sort by date and time before i group because GROUP BY must be before ORDER BY!


ORDER BY date and time BEFORE GROUP BY name in mysql

I often find myself creating a [`Dictionary`][dict] with a non-trivial value class (e.g. [`List`][list]), and then always writing the same code pattern when filling in data.

For example:

&lt;!-- language: lang-csharp --&gt;

    var dict = new Dictionary&lt;string, List&lt;string&gt;&gt;();
    string key = &quot;foo&quot;;
    string aValueForKey = &quot;bar&quot;;

That is, I want to insert `&quot;bar&quot;` into the list that corresponds to key `&quot;foo&quot;`, where key `&quot;foo&quot;` might not be mapped to anything.

This is where I use the ever-repeating pattern:

&lt;!-- language: lang-csharp --&gt;

    List&lt;string&gt; keyValues;
    if (!dict.TryGetValue(key, out keyValues))
      dict.Add(key, keyValues = new List&lt;string&gt;());
    keyValues.Add(aValueForKey);

Is there a more elegant way of doing this?

Related questions that don&#39;t have answers to this question:

* [Is there an IDictionary implementation that returns null on missing key instead of throwing?][1]
* [Find-or-insert with only one lookup in c# dictionary][2]
* [Dictionary returning a default value if the key does not exist][3]

 [dict]: http://msdn.microsoft.com/en-us/library/xfhwa508.aspx
 [list]: http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx
 [1]: https://stackoverflow.com/q/538729/974531
 [2]: https://stackoverflow.com/q/6408916/974531
 [3]: https://stackoverflow.com/q/2601477/974531

.NET Dictionary: get or create new

A very frequently asked question here is how to do an upsert, which is what MySQL calls `INSERT ... ON DUPLICATE UPDATE` and the standard supports as part of the `MERGE` operation.

Given that PostgreSQL doesn&#39;t support it directly (before pg 9.5), how do you do this? Consider the following:

    CREATE TABLE testtable (
        id integer PRIMARY KEY,
        somedata text NOT NULL
    );
    
    INSERT INTO testtable (id, somedata) VALUES
    (1, &#39;fred&#39;),
    (2, &#39;bob&#39;);

Now imagine that you want to &quot;upsert&quot; the tuples `(2, &#39;Joe&#39;)`, `(3, &#39;Alan&#39;)`, so the new table contents would be:

    (1, &#39;fred&#39;),
    (2, &#39;Joe&#39;),    -- Changed value of existing tuple
    (3, &#39;Alan&#39;)    -- Added new tuple

That&#39;s what people are talking about when discussing an `upsert`. Crucially, any approach must be *safe in the presence of multiple transactions working on the same table* - either by using explicit locking, or otherwise defending against the resulting race conditions.

This topic is discussed extensively at https://stackoverflow.com/q/1109061/398670, but that&#39;s about alternatives to the MySQL syntax, and it&#39;s grown a fair bit of unrelated detail over time. I&#39;m working on definitive answers.

These techniques are also useful for &quot;insert if not exists, otherwise do nothing&quot;, i.e. &quot;insert ... on duplicate key ignore&quot;.

Content Type	Original Author	Original Content on Stackoverflow
Question	Muleskinner	View Question on Stackoverflow
Solution 1 - Mysql	Naveed	View Answer on Stackoverflow
Solution 2 - Mysql	Chris Snowden	View Answer on Stackoverflow
Solution 3 - Mysql	Abhay Shiro	View Answer on Stackoverflow
Solution 4 - Mysql	kairos	View Answer on Stackoverflow
Solution 5 - Mysql	piotrpo	View Answer on Stackoverflow

Update a column in MySQL

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

Solution 4 - Mysql

Solution 5 - Mysql

Best way to serialize/unserialize objects in JavaScript?

Web Scraping in a Google Chrome Extension (JavaScript + Chrome APIs)

Attributions