Dynamic SQL Pivot

gistfile1.txt

SET @sql = NULL;
SELECT
 GROUP_CONCAT(
	CONCAT(
		'MAX(IF(cf.name =''',
		name,
		''',cv.field_value,NULL)) AS ',
		'`',
		name,
		'`'
	)
 ) INTO @sql
FROM user_account_custom_fields 
WHERE visible = 1;
SET @sql = CONCAT(
				'SELECT ua.id,ua.email,',
				@sql,
				' FROM user_accounts ua',
				' LEFT JOIN user_account_custom_field_values cv ON (cv.user_account_id=ua.id)',
				' LEFT JOIN user_account_custom_fields cf ON (cf.id = cv.user_account_custom_field_id)',
				
				' GROUP BY ua.id'
			);
PREPARE stmt FROM @sql;
EXECUTE stmt;
========================================================

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'MAX(IF(md.metakey = ''',
      metakey,
      ''', md.metavalue, NULL)) AS ',
      metakey
    )
  ) INTO @sql
FROM metadata;
SET @sql = CONCAT('SELECT s.id, s.name,',
					@sql, 
					' FROM subjects s 
                   LEFT JOIN metadata md
                    ON s.id = md.subject_id
					
                   GROUP BY s.id
					ORDER BY color ASC
					');

PREPARE stmt FROM @sql;
EXECUTE stmt;