mysql导出数据字典

## use information_schema


SELECT
    T.TABLE_SCHEMA AS '数据库名称',
    T.TABLE_NAME AS '表名',
    C.ORDINAL_POSITION AS '字段编号',
    C.COLUMN_NAME AS '字段名',
    C.COLUMN_TYPE AS '数据类型',
    C.IS_NULLABLE AS '允许为空',
    C.COLUMN_KEY AS '键类型',
    C.EXTRA AS '自增属性',
    C.CHARACTER_SET_NAME AS '编码名称',
    C.COLUMN_COMMENT AS '字段说明'
FROM
    COLUMNS C
INNER JOIN TABLES T ON C.TABLE_SCHEMA = T.TABLE_SCHEMA
AND C.TABLE_NAME = T.TABLE_NAME
WHERE
    T.TABLE_SCHEMA = 'mysql'	### 要导出的数据库
    
    
## 将查询结果导出