MySql - Get available Database, Tables, Columns and their Details

Get available database and their information: 
select * from INFORMATION_SCHEMA.SCHEMATA; Result Set Columns:

1. CATALOG_NAME
2. SCHEMA_NAME
3. DEFAULT_CHARACTER_SET_NAME
4. DEFAULT_COLLATION_NAME
5. SQL_PATH

Note: SCHEMA_NAME column contains the database names as you need.

Get available table names from a database:
select TABLE_NAME from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='test_db';

Result Set Columns:

• TABLE_NAME contains the table name

Get table column details:
select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, COLUMN_KEY, EXTRA from INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA='test_db' and TABLE_NAME='user_profile';

If you want checkout INFORMATION_SCHEMA database inside MySql for more.