latin1_swedish_ci to utf8_general_ci http://bingu.net/472/latin1_swedish_ci-to-utf8_general_ci/

latin1_to_utf8.php

<?php
define('DB_NAME', 'putyourdbnamehere');    // 数据库名
define('DB_USER', 'usernamehere');     // MySQL用户名
define('DB_PASSWORD', 'yourpasswordhere'); // 密码
define('DB_HOST', 'localhost');    // 很大可能你无需修改此项

function UTF8_DB_Converter_DoIt() {
  $tables = array();
	$tables_with_fields = array();

	// Since we cannot use the WordPress Database Abstraction Class (wp-db.php),
	// we have to make an a stand-alone/direct connection to the database.
	$link_id = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD) or die('Error establishing a database connection');
	mysql_select_db(DB_NAME, $link_id);

	// Gathering information about tables and all the text/string fields that can be affected
	// during the conversion to UTF-8.
	$resource = mysql_query("SHOW TABLES", $link_id);
	while ( $result = mysql_fetch_row($resource) )
		$tables[] = $result[0];

	if ( !empty($tables) ) {
		foreach ( (array) $tables as $table ) {
			$resource = mysql_query("EXPLAIN $table", $link_id);
			while ( $result = mysql_fetch_assoc($resource) ) {
				if ( preg_match('/(char)|(text)|(enum)|(set)/', $result['Type']) )
					$tables_with_fields[$table][$result['Field']] = $result['Type'] . " " . ( "YES" == $result['Null'] ? "" : "NOT " ) . "NULL " .  ( !is_null($result['Default']) ? "DEFAULT '". $result['Default'] ."'" : "" );
			}
		}

		// Change all text/string fields of the tables to their corresponding binary text/string representations.
		foreach ( (array) $tables as $table )
			mysql_query("ALTER TABLE $table CONVERT TO CHARACTER SET binary", $link_id);

		// Change database and tables to UTF-8 Character set.
		mysql_query("ALTER DATABASE " . DB_NAME . " CHARACTER SET utf8", $link_id);
		foreach ( (array) $tables as $table )
			mysql_query("ALTER TABLE $table CONVERT TO CHARACTER SET utf8", $link_id);

		// Return all binary text/string fields previously changed to their original representations.
		foreach ( (array) $tables_with_fields as $table => $fields ) {
			foreach ( (array) $fields as $field_type => $field_options ) {
				mysql_query("ALTER TABLE $table MODIFY $field_type $field_options", $link_id);
			}
		}

		// Optimize tables and finally close the mysql link.
		foreach ( (array) $tables as $table )
			mysql_query("OPTIMIZE TABLE $table", $link_id);
		mysql_close($link_id);
	} else {
		die('<strong>There are no tables?</strong>');
	}

	return true;
}
UTF8_DB_Converter_DoIt();
?>