String Functions and Operators +----------------+----------------+ | 0100 | 0100 | +----------------+----------------+ mysql>  SELECT HEX(CHAR(1,0,0)), HEX(CHAR(256*256)); +------------------+--------------------+ | HEX(CHAR(1,0,0)) | HEX(CHAR(256*256)) | +------------------+--------------------+ | 010000 | 010000 | +------------------+--------------------+ mysql>  SELECT CHARSET(CHAR(X’65’)), CHARSET(CHAR(X’65’ USING utf8)); +----------------------+---------------------------------+ | CHARSET(CHAR(X’65’)) | CHARSET(CHAR(X’65’ USING utf8)) | +----------------------+---------------------------------+ | binary | utf8 | +----------------------+---------------------------------+ mysql>  SELECT CONCAT(’My’, ’S’, ’QL’); -> ’MySQL’ mysql>  SELECT CONCAT(’My’, NULL, ’QL’); -> NULL mysql>  SELECT CONCAT(14.3); -> ’14.3’ mysql>  SELECT ’My’ ’S’ ’QL’; -> ’MySQL’ 2174 If  CONCAT()  is invoked from within the  mysql  client, binary string results display using hexadecimal notation, depending on the value of the  --binary-as-hex . For more information about that option, see Section 4.5.1, “mysql — The MySQL Command-Line Client” . For quoted strings, concatenation can be performed by placing the strings next to each other: CONCAT()  returns  NULL  if any argument is  NULL . Returns the string that results from concatenating the arguments. May have one or more arguments. If all arguments are nonbinary strings, the result is a nonbinary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent nonbinary string form. CHARACTER_LENGTH()  is a synonym for  CHAR_LENGTH() . Returns the length of the string  str , measured in characters. A multibyte character counts as a single character. This means that for a string containing five 2-byte characters,  LENGTH()  returns  10 , whereas CHAR_LENGTH()  returns  5 . If  CHAR()  is invoked from within the  mysql  client, binary strings display using hexadecimal notation, depending on the value of the  --binary-as-hex . For more information about that option, see Section 4.5.1, “mysql — The MySQL Command-Line Client” . If  USING  is given and the result string is illegal for the given character set, a warning is issued. Also, if strict SQL mode is enabled, the result from  CHAR()  becomes  NULL . By default,  CHAR()  returns a binary string. To produce a string in a given character set, use the optional USING  clause: • CHAR_LENGTH( str ) • CHARACTER_LENGTH( str ) • CONCAT( str1 , str2 ,...)