MySQL : how to remove double or more spaces from a string?

Question

I couldn\'t find this question for MySQL so here it is:

I need to trim all double or more spaces in a string to 1 single space.

For example: \"The  

Answer 1

If you are using php....

try{
$con = new PDO ("mysql:host=localhost;dbname=dbasename","root","");
}
catch(PDOException $e){
echo "error".$e-getMessage();   
}

$select = $con->prepare("SELECT * FROM table");
$select->setFetchMode(PDO::FETCH_ASSOC);
$select->execute();

while($data=$select->fetch()){ 

$id = $data['id'];
$column = $data['column'];

$column = trim(preg_replace('/\s+/',' ', $column)); // remove all extra space


$update = $con->prepare("UPDATE table SET column=:column WHERE id='$id'");
$update->bindParam(':column', $column );
$update->execute();

// echo $column."<br>";
} 

Answer 2

This solution isn't very elegant but since you don't have any other option:

UPDATE t1 set str = REPLACE( REPLACE( REPLACE( str, "  ", " " ), "  ", " " ), "  ", " " );

Answer 3

I know this question is tagged with mysql, but if you're fortunate enough to use MariaDB you can do this more easily:

SELECT REGEXP_REPLACE(column, '[[:space:]]+', ' ');

Answer 4

After searching I end up writing a function i.e

drop function if exists trim_spaces;

delimiter $$

CREATE DEFINER=`root`@`localhost` FUNCTION `trim_spaces`(`dirty_string` text, `trimChar` varchar(1))
    RETURNS text
    LANGUAGE SQL
    NOT DETERMINISTIC
    CONTAINS SQL
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN
  declare cnt,len int(11) ;
  declare clean_string text;
  declare chr,lst varchar(1);

  set len=length(dirty_string);
  set cnt=1;  
  set clean_string='';

 while cnt <= len do
      set  chr=right(left(dirty_string,cnt),1);           

      if  chr <> trimChar OR (chr=trimChar AND lst <> trimChar ) then  
          set  clean_string =concat(clean_string,chr);
      set  lst=chr;     
     end if;

     set cnt=cnt+1;  
  end while;

  return clean_string;
END
$$
delimiter ;

USAGE:

set @str='------apple--------banana-------------orange---' ;

select trim_spaces( @str,'-')

output: apple-banana-orange-

parameter trimChar to function could by any character that is repeating and you want to remove .

Note it will keep first character in repeating set

cheers :)

Answer 5

If you want to update the existing column which has multiple spaces into one then this update query will be helpful:

UPDATE your_table SET column_that_you_want_to_change= REGEXP_REPLACE(column_that_you_want_to_change, '[[:space:]]+', ' ');