Question

Is there any way using which I can change the case of column names. I need to do this as I have several tables in which some of them have column names all in upper case and some of them have column names all in lower case or tables has combination of upper and lower case column names.

Any input will be a great help.

Thanks,
Manasi

Answer 1

You can use ALTER TABLE to rename tables, and select from information_schema.columns to get columns with whichever naming scheme you don’t want. Combine those with dynamic SQL (you can use PREPARE for this purpose) or a script to generate and execute the SQL statements. However, SQL is generally case insensitive, so these changes would be cosmetic.

Untested examples to generate column renaming queries (generated queries may drop column attributes):

-- before use:
-- * change regexp to match columns to rename
-- * change collation to match table/column default
SELECT CONCAT('ALTER TABLE `', table_schema, '`.`', table_name, 
              '` CHANGE `', column_name, '` `', LOWER(column_name), '` ', column_type,
              IF(IS_NULLABLE='NO',' NOT NULL',''),
              IF(column_default <> '', CONCAT(' DEFAULT ', column_default), ''), 
               ' ', extra )
  FROM information_schema.columns
  WHERE column_name REGEXP '^[A-Z]' COLLATE utf8_bin
    AND table_schema <> 'information_schema';

-- or:
SELECT CONCAT('ALTER TABLE `', table_schema, '`.`', table_name, 
              '` CHANGE `', column_name, '` `', LOWER(column_name), '` ', column_type,
              IF(IS_NULLABLE='NO',' NOT NULL',''),
              IF(column_default <> '', CONCAT(' DEFAULT ', column_default), ''), 
               ' ', extra )
  FROM information_schema.columns 
  WHERE LEFT(column_name, 1) = UPPER(LEFT(column_name,1)) COLLATE utf8_bin 
    AND table_schema != 'information_schema';