利用mysql的information_schema数据库里的columns表可以快速导出数据字典

SELECT
    TABLE_NAME AS '表名',
    COLUMN_NAME AS '字段名',
    COLUMN_TYPE AS '数据类型',
    IS_NULLABLE AS '允许为空',
    EXTRA AS 'PK',
    COLUMN_COMMENT AS '字段说明' 
FROM
    information_schema.`COLUMNS` 
WHERE
    TABLE_SCHEMA = 'hr' 
    OR TABLE_SCHEMA = 'attendance'

以上选择出几个常用数据结构字段， TABLE_SCHEMA为数据库名， TABLE_NAME 为表名。

然后选择导出，选择你要导出的格式


显示导出成功，打开就显示下面一样了

下面列出columns表的字段，在生成数据字典时，可以根据需求自由选择。

SELECT
TABLE_CATALOG,
TABLE_SCHEMA as 数据库名,
TABLE_NAME as 表名,
COLUMN_NAME as 字段名,
ORDINAL_POSITION as 字段位置,
COLUMN_DEFAULT as 字段默认值,
IS_NULLABLE 是否允许空值,
DATA_TYPE as 数据类型,
CHARACTER_MAXIMUM_LENGTH as 以字符为单位的最大长度,
CHARACTER_OCTET_LENGTH as 以字节为单位的最大长度,
NUMERIC_PRECISION as 数值类型的长度,
NUMERIC_SCALE as 小数点精度,
DATETIME_PRECISION as 回的日期时间值的精度,
CHARACTER_SET_NAME as 编码方式,
COLLATION_NAME as 校对集,
COLUMN_TYPE as 字段类型,
COLUMN_KEY as 键,
EXTRA as 额外的信息例如自动递增在这里显示,
PRIVILEGES as 权限,
COLUMN_COMMENT as 字段注释,
GENERATION_EXPRESSION
FROM
    information_schema. COLUMNS
WHERE
    TABLE_SCHEMA = 'xxx'

SELECT
b.`表注释`,
    INFORMATION_SCHEMA.COLUMNS.TABLE_NAME AS '表名',
    information_schema.`COLUMNS`.COLUMN_NAME AS '字段名',
    information_schema.`COLUMNS`.COLUMN_TYPE AS '数据类型',
		information_schema.`COLUMNS`.COLUMN_DEFAULT as 字段默认值,
		information_schema.`COLUMNS`.CHARACTER_MAXIMUM_LENGTH as 以字符为单位的最大长度,
		information_schema.`COLUMNS`.CHARACTER_OCTET_LENGTH as 以字节为单位的最大长度,
		information_schema.`COLUMNS`.NUMERIC_PRECISION as 数值类型的长度,
		information_schema.`COLUMNS`.NUMERIC_SCALE as 小数点位数,
    information_schema.`COLUMNS`.IS_NULLABLE AS '允许为空',
    information_schema.`COLUMNS`.COLUMN_COMMENT AS '字段说明' 
FROM
    information_schema.`COLUMNS` LEFT JOIN 
		(SELECT
		INFORMATION_SCHEMA.Tables.TABLE_COMMENT AS '表注释',
    INFORMATION_SCHEMA.Tables.TABLE_NAME AS '表名'
FROM
    INFORMATION_SCHEMA.Tables 
WHERE
    TABLE_SCHEMA = 'sub_test') b
		on INFORMATION_SCHEMA.COLUMNS.TABLE_NAME = b.`表名`
WHERE
    TABLE_SCHEMA = 'sub_test'