要找出所有数据库中存在的 ENUM('M','F','NA') 数据类型列的数量，哪个查询是正确的？( )
SELECT count(*) FROM information_schema.columns WHERE data_type = 'enum' ;
select count(*) from information_schema.column where column_name="ENUM('M','F','NA')";
SELECT count(*) FROM information_schema.columns WHERE data_type = "ENUM('M','F','NA')" ;
SELECT count(*) FROM information_schema.columns WHERE column_type = "ENUM('M','F','NA')" ;
