Why does a string with the same encoding renders differently on MySQL and HTML？

Question

This is the input string that I entered in my HTML form：

ラムダ計算（λ - 、lambda - ）は、関数の定義、関数の適用、誘導関数を式で表現するための形式のシステムである。 1930年代アロンゾ・チャーチが数学基礎論を研究する過程で、ラムダ計算の形式を提案し

This is the string that appears in MySQL database field of TINYTEXT type：

람ë <¤ëŒ€ì~（λ - 、lambda - ）ëŠ "함ì~ì•ì~、함ì~ììš©、 ê・€ë、©ì함ì~ë¥ ¼ì~ì<으로í'œí~「í•~기ìœ「í•œí~•ì<ì²'ê³ "ì'

This is the output on the HTML page upon querying：

ラムダ計算（λ - 、lambda - ）は、関数の定義、関数の適用、誘導関数を式で表現するための形式チェギェイ

Both the HTML and the database are encoded in UTF-8。 There are two things which I would like to ask：

1. Why does the field in MySQL database render differently from the ones in HTML？
2. What can I do to catch the length in bytes of the above string to ensure it is within the 255 limit of TINYTEXT？

Answer 1

Most likely the most common pitfall：You're not setting your database connection to the right encoding。 See why do i have to use mb_convert_encoding($name,'ISO-8859-15','utf-8') to get accented chars to display?。