SQL Query inserting into a table data present in other tables
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1. category table 
2. sub category Table

Structure for which is 
Category Table
id, name, article.
1, About, About content
2, Contact Us, Call us on

AND for sub-category-table
id, cat_id, name 
1, 1, History
2, 1, Offices

can some please tell me a single SQL query that can insert data to sub-category-table provided i have (Category Table name eg: **About** but not id, & Sub Category name : Carrer) i can use the  Category Table name for finding the corresponding id and use it for insertion into cat_id BUT how?