sql语句：
复制代码 代码示例:
select
columns.table_name, columns.column_default, columns.ordinal_position, columns.column_name, columns.column_type, columns.column_key, columns.extra, columns.column_comment, tables.table_comment
from
information_schema.columns
left join information_schema.tables on tables.table_name = columns.table_name
where
columns.table_schema = '{$dbname}'
