mysql查询数据库某个表的所有字段及字段的长度及是否为空

1.
SELECT
            c.COLUMN_NAME name,
            c.COLUMN_COMMENT 'desc',
            c.DATA_TYPE type,
            CASE DATA_TYPE
                WHEN 'longtext' THEN
                    c.CHARACTER_MAXIMUM_LENGTH
                WHEN 'varchar' THEN
                    c.CHARACTER_MAXIMUM_LENGTH
                WHEN 'double' THEN
                    CONCAt_ws(
                        ',',
                        c.NUMERIC_PRECISION,
                        c.NUMERIC_SCALE
                    )
                WHEN 'decimal' THEN
                    CONCAt_ws(
                        ',',
                        c.NUMERIC_PRECISION,
                        c.NUMERIC_SCALE
                    )
                WHEN 'int' THEN
                    c.NUMERIC_PRECISION
                WHEN 'bigint' THEN
                    c.NUMERIC_PRECISION
            END AS length,
            CASE c.IS_NULLABLE 
                WHEN 'yes' THEN 'false'
                WHEN 'no' THEN 'on'
            END AS notnull
        FROM
            information_schema.COLUMNS c
        WHERE
            table_schema = '数据库的名字'
        AND table_name = '表的名字';
2.
    select column_name,column_comment,data_type from information_schema.columns WHERE
            table_schema = '数据库的名称'
        AND table_name = '表的名称' ;