mysql 查表字段结构及注释说明及查库中一共有多少表的sql语句

查表字段结构及注释说明

select  COLUMN_NAME 字段名,
column_comment 字段说明,
column_type 字段类型,
column_key 约束 from information_schema.columns 
where table_schema = 'myDatabaseName'
and table_name = 'myTableName' ; 

查库里表的总数

SELECT COUNT(TABLE_NAME) FROM information_schema.tables WHERE TABLE_SCHEMA = 'myDatabaseName'