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Increment value in MySQL update query

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How do I increment in MySQL?

Syntax for MySQLMySQL uses the AUTO_INCREMENT keyword to perform an auto-increment feature. By default, the starting value for AUTO_INCREMENT is 1, and it will increment by 1 for each new record. VALUES ('Lars','Monsen'); The SQL statement above would insert a new record into the "Persons" table.

How do I update two columns at a time in MySQL?

MySQL UPDATE command can be used to update multiple columns by specifying a comma separated list of column_name = new_value. Where column_name is the name of the column to be updated and new_value is the new value with which the column will be updated.

How do I add a number to a column in MySQL?

In syntax, First, you must specify the name of the table. After that, in parenthesis, you must specify the column name of the table, and columns must be separated by a comma. The values that you want to insert must be inside the parenthesis, and it must be followed by the VALUES clause.

What is the syntax for Update command in MySQL?

MySQL Update Command Syntax The basic syntax of the Update query in MySQL is as shown below. UPDATE `table_name` is the command that tells MySQL to update the data in a table . SET `column_name` = `new_value' are the names and values of the fields to be affected by the update query.


You could also just do this:

mysql_query("
    UPDATE member_profile 
    SET points = points + 1
    WHERE user_id = '".$userid."'
");

You can do this without having to query the actual amount of points, so it will save you some time and resources during the script execution.

mysql_query("UPDATE `member_profile` SET `points`= `points` + 1 WHERE `user_id` = '".intval($userid)."'");

Else, what you were doing wrong is that you passed the old amount of points as a string (points='5'+1), and you can't add a number to a string. ;)


Hope I'm not going offtopic on my first post, but I'd like to expand a little on the casting of integer to string as some respondents appear to have it wrong.

Because the expression in this query uses an arithmetic operator (the plus symbol +), MySQL will convert any strings in the expression to numbers.

To demonstrate, the following will produce the result 6:

SELECT ' 05.05 '+'.95';

String concatenation in MySQL requires the CONCAT() function so there is no ambiguity here and MySQL converts the strings to floats and adds them together.

I actually think the reason the initial query wasn't working is most likely because the $points variable was not in fact set to the user's current points. It was either set to zero, or was unset: MySQL will cast an empty string to zero. For illustration, the following will return 0:

SELECT ABS('');

Like I said, I hope I'm not being too off-topic. I agree that Daan and Tomas have the best solutions for this particular problem.


"UPDATE member_profile SET points = points + 1 WHERE user_id = '".$userid."'"

Also, to "increment" string, when update, use CONCAT

update dbo.test set foo=CONCAT(foo, 'bar') where 1=1

Who needs to update string and numbers SET @a = 0; UPDATE obj_disposition SET CODE = CONCAT('CD_', @a:=@a+1);