decided with MSSQL to study MySQL on a little bit and came across a problem immediately …

Question: Why is it not working?

set @counter = 1;
While (@counter & lt; 20) do
  SET @Counter = @Counter + 1;
End While;

SQL version is: MySQL-Installer-Community-5.11.0.

compiled this thing in Eclipse, as well as in the console using: Delimiter //

how much did not google, how many different options for other cycles did not try, everything is a stupid, says the syntactic error.

This is:

set @counter = @counter + 1;

And this is:

set @counter = 1;

Compile separately normally, but with the While-Ohm … = (

Begin after DO has already tried to put. I also tried to put a name with a colon and then close this thing in End. It does not work. Repeat also does not work …

In the procedure, by the way, also does not work:

create procedure mypro ()
Begin.
Set @counter = 1;
While (@counter & lt; 20) do
  SET @Counter = @Counter + 1;
End While;
End.

Where am I stupid?

Answer 1, Authority 100%

While Only inside Begin End works. In general, this code works for sure:

create procedure procedure1 ()
Begin.
set @p: = 2;
While @ P & LT; 20 do set @p: = @ p ​​+ 1; End While;
end;

Answer 2, Authority 25%

In fact, the answer from above (@ vkovalchuk88) exhaustive, all logical operators, such as (if statement, Switch Case, While Do, Loop …)
I don’t work in the lads or procedures, see how to write functions and procedures in SQL, there, in addition, everything, except foreach, I did not find it, it is written that it is introduced to Musk from 2011, but my MySQL does not see it.

https://www.w3schools.com/sql/sql_ref_sqlserver.asp

https: // docs .microsoft.com / EN-US / SQL / T-SQL / Statements / Create-Function-Transact-SQL

https: // docs .microsoft.com / EN-US / SQL / T-SQL / Statements / Create-Procedure-transact-SQL

https://www.w3resource.com/sql/sql-procedure.php

The only one kind of function returns the result, and the procedure seems to be no, this is your member.

Regarding your procedure, lacking the delimetra, and the sign “//”, at the beginning and at the end, as described in the code.
concat () and @result , just to demonstrate his work.

deleimiter // - Is ImpoRant
  CREATE PROCEDURE MYPRO ()
  Begin.
  Set @counter = 1;
  Set @result = "";
  While (@counter & lt; 20) do
    SET @Counter = @Counter + 1;
    Set @result = concat (@Result, ",", @counter);
  End While;
  SELECT @RESULT;
END // - End Need Be WITH "//"

now works