Type `\c`.

When you start up MySQL, you&#39;ll likely see this message:

    Type &#39;help;&#39; or &#39;\h&#39; for help. Type &#39;\c&#39; to clear the buffer.

The &quot;buffer&quot; that it&#39;s referring to is the command/query buffer.

First type &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;a&lt;/kbd&gt;, then &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;k&lt;/kbd&gt;.

Use one of the following shortcuts to delete the current line:

 - Type &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;u&lt;/kbd&gt; to delete everything from the cursor back to the line start
 - Type &lt;kbd&gt;Ctrl&lt;/kbd&gt; + &lt;kbd&gt;k&lt;/kbd&gt; to delete everything from the cursor to the end of the line

Otherwise as already indicated type &lt;kbd&gt;\c&lt;/kbd&gt; at the end of the current line (a shortcut for the `clear` command) and then press &lt;kbd&gt;Enter&lt;/kbd&gt;.


If it&#39;s a long command I usually arrow to the beginning of the command and add gibberish, so it won&#39;t execute, but I can up-arrow and gain access without having to re-type it. Otherwise if you want to not execute it, just hit the up-arrow and it should scroll you through your command history. Find a short command, backspace, then type whatever you want.

Depends on your shell&#39;s key bindings.  You could press home or what ever key sequence you use to get back to the start, prefix your query with X or what ever to make it syntactically invalid, hit enter and you&#39;re good

If you came here hoping to find the same answer in Transact-SQL, type `RESET`

In mysql 5.7, this has been resolved. You can now do `ctrl-c` to exit the SQL command line.

Is there a function to count the number of words in a string?
For example:

    str1 &lt;- &quot;How many words are in this sentence&quot;

to return a result of 7.

Count the number of all words in a string

I want to remove keys that match &quot;user*&quot;.

How do I do that in redis command line?

How do I remove keys?

Suppose you&#39;re typing a command line query into a MySQL database and you need to cancel out and start over. From a bash shell you could just type ctrl-c and get a new prompt. In MySQL, ctrl-c would exit the client and return you to the shell. 

For example, I have a long, complex SELECT statement typed in but I haven&#39;t yet hit return. I realize that I don&#39;t want to send the command but I want to have the command on-screen so I can use it as a reference. I&#39;d like to bail out without quitting MySQL. Any ideas?

Key point: [the command hasn&#39;t yet been executed][1].


  [1]: https://stackoverflow.com/questions/498344/how-do-i-interupt-a-long-query-in-the-mysql-command-line-tool-without-quitting-m

How do you clear an unexecuted MySQL query from the command line?

Suppose you're typing a command line query into a MySQL database and you need to cancel out and start over. From a bash shell you could just type ctrl-c and get a new prompt. In MySQL, ctrl-c would exit the client and return you to the shell.
For example, I have a long, complex SELECT statement typed in but I haven't yet hit return. I realize that I don't want to send the command but I want to have the command on-screen so I can use it as a reference. I'd like to bail out without quitting MySQL. Any ideas?
Key point: <a href="https://stackoverflow.com/questions/498344/how-do-i-interupt-a-long-query-in-the-mysql-command-line-tool-without-quitting-m" target="_blank" rel="noopener noreferrer">the command hasn't yet been executed</a>.

My application download mails over IMAP and stores them in a MySQL database. Earlier I was supporting mails size upto 10 MB and hence a &#39;mediumtext&#39; column to store the mail content was enough. Now I need to support mails upto 30MB. So I changed the datatype for the column to &#39;largetext&#39;. Yesterday a mail with size 25 MB was stored. After that whenever I execute mysqldump command it throws error:
&lt;pre&gt;
mysqldump: Error 2020: Got packet bigger than &#39;max_allowed_packet&#39; bytes when dumping table `ib_mailbox_backup` at row: 3369
&lt;/pre&gt;

Row 3369 contains the 25 MB mail.

In MySQL config I increased the &#39;max_allowed_packet&#39; from 64M to 512M and it still fails with the same error. Executing the mysqldump command on the same machine where MySQL server is running. How do I solve this? 

mysqldump error: Got packet bigger than max_allowed_packet&#39;

Is there a way to check if a table exists *without* selecting and checking values from it?

That is, I know I can go `SELECT testcol FROM testtable` and check the count of fields returned, but it seems there must be a more direct / elegant way to do it.

Check if MySQL table exists without using &quot;select from&quot; syntax?

I want to begin writing queries in MySQL.

`show grants` shows:

    +--------------------------------------+
    | Grants for @localhost                |
    +--------------------------------------+
    | GRANT USAGE ON *.* TO &#39;&#39;@&#39;localhost&#39; |
    +--------------------------------------+

I do not have any user-id but when I want to make a user I don&#39;t have privilleges, also I don&#39;t know how to make privileges when even I don&#39;t have one user!

    mysql&gt; CREATE USER &#39;parsa&#39;@&#39;localhost&#39; IDENTIFIED BY &#39;parsa&#39;;
    ERROR 1227 (42000): Access denied; you need (at least one of) the CREATE USER pr
    ivilege(s) for this operation

I tried to sign in as root:

    mysql&gt; mysql -u root -p;
    ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
    corresponds to your MySQL server version for the right syntax to use near &#39;mysql
     -u root -p&#39; at line 1
    mysql&gt; mysql -u root -p root;
    ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
    corresponds to your MySQL server version for the right syntax to use near &#39;mysql
     -u root -p root&#39; at line 1




ERROR 1044 (42000): Access denied for user &#39;&#39;@&#39;localhost&#39; to database &#39;db&#39;

I was repairing this table suddenly server hanged and when I returned back all tables are ok but this one showing &#39;in use&#39; and when I try to repair it doesn&#39;t proceed.

&gt;    ERROR 144 - Table &#39;./extas_d47727/xzclf_ads&#39; is marked as crashed and last (automatic?) repair failed 

What can I do to repair it?

MySQL table is marked as crashed and last (automatic?) repair failed

I have a table called `provider`. I have three columns called `person`, `place`, `thing`. There can be duplicate persons, duplicate places, and duplicate things, but there can never be a dupicate person-place-thing combination.

How would I ALTER TABLE to add a composite primary key for this table in MySQL with the these three columns?

ALTER TABLE to add a composite primary key

Suppose you have an .EXE and you want to check if it has Command-Line Options. How can one know if the .EXE has this ability. In my case I know that Nir Sofers [WebBrowserPassView.exe](http://www.nirsoft.net/utils/web_browser_password.html) has the ability to start it via cmd.exe and WebBrowserPassView.exe /stext output.txt. But how can I find out if I don&#39;t know?

How can I find out if an .EXE has Command-Line Options?

I want to execute a text file containing SQL queries, in MySQL.

I tried to run `source /Desktop/test.sql` and received the error: 

&gt; mysql&gt; . \home\sivakumar\Desktop\test.sql ERROR: Failed to open file
&gt; &#39;\home\sivakumar\Desktop\test.sql&#39;, error: 2

Any idea on what I am doing wrong?

How to run SQL script in MySQL?

I&#39;m trying to get `psql` to format nicely and am following the docs [here](http://www.postgresql.org/docs/9.0/static/app-psql.html). Right now, whenever I do a query on tables with lots of columns, no matter how big I make my screen each line overflows into the next line and producing a whole screen of unreadable junk.

The docs (link is above) say there&#39;s a way to align columns nicely for more readable output.

Normally, to start `psql`, I just type:

&gt; psql

and hit *Enter*. Now I&#39;m trying:

&gt; psql \pset format aligned

And getting an error:

    could not change directory to &quot;/root&quot;
    psql: warning: extra command-line argument &quot;aligned&quot; ingored
    psql: FATAL: Indent authentication failed for user &quot;format&quot;

Any ideas as to how I could get these command-line args to work for me?

PostgreSQL psql terminal command

How to beautify JSON in Python?

If I have a custom shell script or programs, that I created myself or downloaded from the web, and I want to be able to execute this from the CLI, is there the standard location to put this in Linux/Unix directory structure?

    /usr/bin ?
    /usr/local/bin ?
    /usr/lib ?
    /usr/sbin ?
    /bin ?
    /sbin ?
    /var ?

I usually put it under my ~/bin folder and put it in PATH, but it doesn&#39;t seem clean. And everytime I downloaded a new program, I have to put it in the PATH again.

Content Type	Original Author	Original Content on Stackoverflow
Question	Logan	View Question on Stackoverflow
Solution 1 - Mysql	ruakh	View Answer on Stackoverflow
Solution 2 - Mysql	untill	View Answer on Stackoverflow
Solution 3 - Mysql	bladerz	View Answer on Stackoverflow
Solution 4 - Mysql	Mike Purcell	View Answer on Stackoverflow
Solution 5 - Mysql	atxdba	View Answer on Stackoverflow
Solution 6 - Mysql	Post Impatica	View Answer on Stackoverflow
Solution 7 - Mysql	dkniffin	View Answer on Stackoverflow

How do you clear an unexecuted MySQL query from the command line?

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

Solution 4 - Mysql

Solution 5 - Mysql

Solution 6 - Mysql

Solution 7 - Mysql

How do I remove keys?

Count the number of all words in a string

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