Cross-SQL statements in Oracle

oracle| statement
Example description

Table structure (red primary key) ==>
Main Table: Test_part_cost_tab (material number table)
Part_no VARCHAR2 (20)
Part_name VARCHAR2 (50)

From the table: Test_part_cost_dt_tab (material number cost data sheet)
Part_no VARCHAR2 (10)
cost_id VARCHAR2 (5)
Cost number

Data ==>
Main Table data:
Part_no Part_name
1 1000 name1000
2 1001 name1001
From table data:
Part_no cost_id Cost
1 1000 100 1.1
2 1000 200 1.2
3 1000 300 1.3
4 1000 321 1.321
5 1001 100 2.1

Cross-Information ==>
Results generated by SQL statements
Part_no part_name cost_100 cost_200 cost_300 cost_321
1 1000 name1000 1.1 1.2 1.3 1.321
2 1001 name1001 2.1 0 0 0

Specific cross-SQL statements:
Select A.part_no,a.part_name,
--sum (B.cost)
SUM (case when b.cost_id = ' m ' then b.cost else 0 end) as cost_100,
SUM (case when b.cost_id = ' Then ' b.cost else 0) as cost_200,
SUM (case when b.cost_id = ' Then ' b.cost else 0) as cost_300,
SUM (case when b.cost_id = ' 321 ' then b.cost else 0-end) as cost_321

From Test_part_cost_tab A,test_part_cost_dt_tab b
where a.part_no = B.part_no
GROUP BY A.part_no,a.part_name

PS: If the main table has data, from the table does not have the data, after the cross will not have the corresponding information
The solution is to use an outer join in the Where condition
where a.part_no = B.part_no (+)

Resources:
Http://www.cnblogs.com/iouniuniu/archive/2004/04/05/5238.aspx ==> The syntax of this article is different from the syntax in this paper
Http://it.icxo.com/htmlnews/2004/11/11/454293.htm
Http://www.itpub.net/176727.html