No there isn&#39;t, check the [manual about the IN function](https://dev.mysql.com/doc/refman/8.0/en/comparison-operators.html#operator_in):

&gt; The number of values in the `IN` list is only limited by the [max_allowed_packet](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_max_allowed_packet) value.

As far as I know in mysql, there is no limit for items in the `IN` statement.

In oracle altough, there is a limit of 1000 items in the `IN` statement.

But more the items in `IN`, your query performance will slow down unless that column is indexed.

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/tNCXz.png

1073741824 This is the limit given in Mysql docs

For example (not sure if most representative example though):

    N &lt;- 1e6
    d1 &lt;- data.frame(x=sample(N,N), y1=rnorm(N))
    d2 &lt;- data.frame(x=sample(N,N), y2=rnorm(N))

This is what I&#39;ve got so far:

    d &lt;- merge(d1,d2)
    # 7.6 sec
    
    library(plyr)
    d &lt;- join(d1,d2)
    # 2.9 sec
    
    library(data.table)
    dt1 &lt;- data.table(d1, key=&quot;x&quot;)
    dt2 &lt;- data.table(d2, key=&quot;x&quot;)
    d &lt;- data.frame( dt1[dt2,list(x,y1,y2=dt2$y2)] )
    # 4.9 sec
    
    library(sqldf)
    sqldf()
    sqldf(&quot;create index ix1 on d1(x)&quot;)
    sqldf(&quot;create index ix2 on d2(x)&quot;)
    d &lt;- sqldf(&quot;select * from d1 inner join d2 on d1.x=d2.x&quot;)
    sqldf()
    # 17.4 sec

What&#39;s the fastest way to merge/join data.frames in R?

I have a textfile, containing something like:

    12,34 EUR 
     5,67 EUR
     ...

There is one whitespace before &#39;EUR&#39; and I ignore 0,XX EUR.

I tried: 

`grep &#39;[1-9][0-9]*,[0-9]\{2\}\sEUR&#39; =&gt; didn&#39;t match !`

`grep &#39;[1-9][0-9]*,[0-9]\{2\} EUR&#39; =&gt; worked !`

`grep &#39;[1-9][0-9]*,[0-9]\{2\}\s*EUR&#39; =&gt; worked !`

`grep &#39;[1-9][0-9]*,[0-9]\{2\}\s[E]UR&#39;  =&gt; worked !`

Can somebody explain me pls, why I can&#39;t use `\s` but `\s*` and `\s[E]` matched?

OS: Ubuntu 10.04, grep v2.5



grep regex whitespace behavior

Hey, I have to use IN condition in my MySQL statement with a large set of ids.

Example

    SELECT * FROM users WHERE id IN (1,2,3,4...100000)

Is there a limit if items the IN statement can have?

MySQL IN condition limit

Hey, I have to use IN condition in my MySQL statement with a large set of ids.
Example
<pre><code class="hljs language-sql">SELECT * FROM users WHERE id IN (1,2,3,4...100000)
</code></pre>
Is there a limit if items the IN statement can have?

In relation to [my other question][1] today I am wondering how to use [MySQL&#39;s `SLEEP(duration)`](http://dev.mysql.com/doc/refman/5.6/en/miscellaneous-functions.html#function_sleep) correctly.

From what I gathered reading MySQL Dev forums and very vague description in MySQL Docs I can&#39;t use it this way:

    SELECT ...
    SLEEP(1); /* wait for a second before another SELECT */
    SELECT ...

So what is it good for then?


  [1]: https://stackoverflow.com/questions/4284162/calling-stored-procedure-sequentially-from-sql-file-and-php-fails-differently

How and when to use SLEEP() correctly in MySQL?

I&#39;m looking for the best way to check and see if any results were returned in a query. I feel like I write this part of code a lot and sometimes I get errors, and sometimes I don&#39;t.

For example, I run this query to check if a username exists before inserting a new one into the database.

    $result = mysql_query(&quot;SELECT * FROM ...&quot;);

Then I want to check and see if any results were returned. Here is one way I do it:

    if (!$result) { PERFORM ACTION }

If the first way doesn&#39;t work, then sometimes this will:

    if (mysql_num_rows($result)==0) { PERFORM ACTION }

Then I even saw that I could do it this way the other day:

    list($total) = mysql_fetch_row($result);
    if ($total==0) { PERFORM ACTION }


What is the best way to do this?

Best way to check if mysql_query returned any results?

I have a logging table that will contain millions of writes for statistical reasons. All the columns are int foreign keys. I am also going to add a timestamp column for each row. Given that DATETIME takes 8bits - I will be using `int(10) unsigned` to cut the storage space (and index on that column) in half. 

However, I&#39;m wondering when this column would no longer work. At 3:14:07AM on 19th January 2038 the value 9,999,999,999 will be a problem for UNIX timestamps - but an unsigned int in MySQL only holds up to 4,294,967,295 and the timestamp 4294967295 is showing an invalid number in my PHP application.

**So what does this mean? Is the end of the storing int timestamps in MySQL going to be sometime in 2021 since it can&#39;t make it all the way to 9999999999?**

**Answer:** 

 1. 2147483647 is 2038 (not 9999999999) so there is no problem. 
 2. `unsigned` isn&#39;t needed since 2147483647 fits fine in a signed MySQL int.

How should unix timestamps be stored in int columns?

What is the location of mysql client `.my.cnf` using XAMPP in Windows?

**Clarification**: This file does not exist by default, so when you create it, where should you place it, in order for the command line client to read it automatically?

What is the location of mysql client &quot;.my.cnf&quot; in XAMPP for Windows?

I need to export a mysql table, but it has like 5gb of entries, so I only want the structure. I am trying to do it from a simple php doing a sql query, how can I do that?

How to dump mysql table structure without data with a SQL query?

How can I use a condition inside a switch statement for JavaScript?
In the example below, a case should match when the variable `liCount` is `&lt;= 5` and `&gt; 0`; however, my code does not work:

```
switch (liCount) {
  case 0:
    setLayoutState(&quot;start&quot;);
    var api = $(&quot;#UploadList&quot;).data(&quot;jsp&quot;);
    api.reinitialise();
    break;
  case liCount &lt;= 5 &amp;&amp; liCount &gt; 0:
    setLayoutState(&quot;upload1Row&quot;);
    var api = $(&quot;#UploadList&quot;).data(&quot;jsp&quot;);
    api.reinitialise();
    break;
  case liCount &lt;= 10 &amp;&amp; liCount &gt; 5:
    setLayoutState(&quot;upload2Rows&quot;);
    var api = $(&quot;#UploadList&quot;).data(&quot;jsp&quot;);
    api.reinitialise();
    break;
  case liCount &gt; 10:
    var api = $(&quot;#UploadList&quot;).data(&quot;jsp&quot;);
    api.reinitialise();
    break;
  default:
    break;
}
```

Appreciate any advice!

JavaScript: using a condition in switch case

I&#39;m trying to compile this in my mind.. i have a table with firstname and lastname fields
and i have a string like &quot;Bob Jones&quot; or &quot;Bob Michael Jones&quot; and several others.

the thing is, i have for example
Bob in firstname, and
Michael Jones in lastname

so i&#39;m trying to 

    SELECT neededfield, CONCAT(firstname, &#39; &#39;, lastname) as firstlast 
      FROM users 
     WHERE firstlast = &quot;Bob Michael Jones&quot;

but it says unknown column &quot;firstlast&quot;.. can anyone help please ?


MySQL select with CONCAT condition

I want to write an if/else statement that tests if the value of a text input does NOT equal either one of two different values. Like this (excuse my pseudo-English code):

&lt;pre&gt;
var test = $(&quot;#test&quot;).val();
if (test does not equal A or B){
    do stuff;
}
else {
    do other stuff;
}
&lt;/pre&gt;

How do I write the condition for the if statement on line 2?

How do I test if a variable does not equal either of two values?

Postgres is the database

Can I use a NULL value for a IN clause? example:

    SELECT *
    FROM tbl_name
    WHERE id_field IN (&#39;value1&#39;, &#39;value2&#39;, &#39;value3&#39;, NULL)

I want to limit to these four values.

I have tried the above statement and it doesn&#39;t work, well it executes but doesn&#39;t add the records with NULL id_fields.

I have also tried to add a OR condition but this just make the query run and run with no end in sight.

    SELECT *
    FROM tbl_name
    WHERE other_condition = bar
    AND another_condition = foo
    AND id_field IN (&#39;value1&#39;, &#39;value2&#39;, &#39;value3&#39;)
    OR id_field IS NULL

Any suggestions? 

IN Clause with NULL or IS NULL

For example if I want to do something if parent element for **used** element hasn&#39;t got `ul` tag as next element, how can I achieve this? 


I try some combination of `.not()` and/or 
`.is()` with no success.

What&#39;s the best method for negate code of a `if else` block?


**My Code**        

    if ($(this).parent().next().is(&#39;ul&#39;)){
       // code...
    }

**I want to achieve this**

Pseudo Code:

    if ($(this).parent().next().is NOT (&#39;ul&#39;)) {
        //Do this..
    }

Content Type	Original Author	Original Content on Stackoverflow
Question	xpepermint	View Question on Stackoverflow
Solution 1 - Mysql	Progman	View Answer on Stackoverflow
Solution 2 - Mysql	Sachin Shanbhag	View Answer on Stackoverflow
Solution 3 - Mysql	praveen	View Answer on Stackoverflow

MySQL IN condition limit

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

grep regex whitespace behavior

What's the fastest way to merge/join data.frames in R?

Attributions