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I have defined a column in my MySQL database as :

ALTER TABLE `my_table` CHANGE `desc` `desc` VARCHAR( 255 ) 
    CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL

However, when I enter text that is longer than 233 characters from my front end the data is truncated.

Changing the size of the column to varchar(511) has made no difference.

I counted the number of characters using PHP's strlen() function and it revealed 233 characters.

Why is MySQL doing this, and how can I save the full string?

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After inserting some strings into this table, try using SELECT LENGTH(`desc`), CHAR_LENGTH(`desc`) FROM my_table; Are there differences? – ypercube Oct 2 '12 at 8:13
@ypercube i changed varchar(255) to text , now its working , but i still dont know why varchar(255) dint – user1537158 Oct 3 '12 at 7:35
1  
Please read this: MySQL Charset/Collate It's a rather long post but the "Best practise" paragraph should point you to where the problem lies in your case. You probably missed one of those settings (replacing 'utf-8' with 'latin1') and your application was sending data in utf8 and not latin. – ypercube Oct 3 '12 at 7:43

1 Answer

up vote -2 down vote

255 is used because it's the largest number of characters that can be counted with an 8-bit number. It maximizes the use of the 8-bit count, without frivolously requiring another whole byte to count the characters above 255.

When used this way, VarChar only uses the number of bytes + 1 to store your text, so you might as well set it to 255, unless you want a hard limit (like 50) on the number of characters in the field.

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