连接两个表并显示仅具有特定条件的记录

I have two tables, quotation and comparitive.

Table quotation has fields: tender_id, supplier_name

Table comparitive has fields: tender_id, sup_name,make,shelf_life,datasheet,coc

Now what I want is I need a query which joins these two tables and show records where quotation.tender_id=comparitive.tender_id and comparitive.tender_id=$tender_id and comparitive.sup_name IN quotation.supplier_name.

How can I achieve that? I have tried different ways but desired output is not coming.

This is what I have tried.

 SELECT comparitive_statement1.sup_name 
, comparitive_statement1.tender_id
, comparitive_statement1.coc
, comparitive_statement1.shelf_life
, comparitive_statement1.make
, comparitive_statement1.datasheet
, quotation_items.supplier_name 
, quotation_items.tender_id 
FROM comparitive_statement1 
, quotation_items 
WHERE comparitive_statement1.tender_id = quotation_items.tender_id 
AND quotation_items.tender_id='$tender_id' 
and quotation_items.supplier_name = comparitive_statement1.sup_name 
group by quotation_items.supplier_name

SELECT cs.sup_name 
, cs.tender_id
, cs.coc
, cs.shelf_life
, cs.make
, cs.datasheet
, q.supplier_name 
FROM comparitive_statement1 cs
LEFT JOIN quatation_items q
ON cs.tender_id = q.tender_id
WHERE q.tender_id='$tender_id' 
AND q.supplier_name = cs.sup_name 
GROUP BY q.supplier_name

This query should work. Also, there is no point to have comparitive_statement1.tender_id and quotation_items.tender_id in the query as they will be identical.