what is wrong in this sql query [closed] - mysql

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I had created two Tables 'tbl_book_info' and 'tbl_books' (table descriptions
are below) in MySQL Database
what should I change in my SQL query
I had used subquery inside WHERE clause.
All Records of 'tbl_books'-
+-------+-------+--------+
| accid | accno | status |
+-------+-------+--------+
| 10001 | 101 | I |
| 10001 | 102 | I |
| 10001 | 103 | A |
| 10002 | 101 | A |
| 10002 | 102 | A |
| 10002 | 103 | I |
| 10002 | 104 | I |
| 10002 | 105 | I |
| 10003 | 101 | A |
| 10003 | 102 | A |
| 10003 | 103 | A |
| 10003 | 104 | I |
| 10003 | 105 | I |
| 10004 | 101 | A |
| 10004 | 102 | I |
| 10004 | 103 | A |
| 10004 | 104 | A |
| 10004 | 105 | A |
| 10005 | 101 | A |
| 10005 | 102 | A |
| 10005 | 103 | A |
| 10005 | 104 | A |
| 10005 | 105 | A |
+-------+-------+--------+
23 rows in set (0.00 sec)
All Records of 'tbl_book_info'-
+----------+------------------+-------+-------------+---------+---------+-------------+---------+--------+---------+---------+
| b_acc_id | b_name | b_qty | b_type | b_auth1 | b_auth2 | b_pub | b_pages | b_rack | b_price | b_about |
+----------+------------------+-------+-------------+---------+---------+-------------+---------+--------+---------+---------+
| 10001 | Java | 3 | Programming | lala | - | kallo | 800 | 1 | 799.00 | - |
| 10002 | Cpp | 5 | Programming | Kallo | - | Mehta group | 400 | 2 | 300.00 | - |
| 10003 | VB.net | 5 | Programming | lalaji | - | amam co. | 479 | 3 | 100.00 | - |
| 10004 | DBMS | 5 | prog | lalal | - | kallo | 888 | 3 | 499.00 | - |
| 10005 | computer network | 5 | Networking | Mirabai | - | kabirdas | 789 | 2 | 800.00 | - |
+----------+------------------+-------+-------------+---------+---------+-------------+---------+--------+---------+---------+
desc tbl_books;
+--------+------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra |
+--------+------------+------+-----+---------+-------+ | accid | int(5) | NO | PRI | 0 | | | accno | int(3) | NO | PRI | 0 | | | status | varchar(1) | YES | | A | |
+--------+------------+------+-----+---------+-------+
desc tbl_book_info;
+----------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+--------------+------+-----+---------+----------------+
| b_acc_id | int(5) | NO | PRI | NULL | auto_increment |
| b_name | varchar(50) | NO | | NULL | |
| b_qty | int(2) | NO | | NULL | |
| b_type | varchar(30) | NO | | NULL | |
| b_auth1 | varchar(50) | NO | | NULL | |
| b_auth2 | varchar(50) | YES | | NULL | |
| b_pub | varchar(50) | NO | | NULL | |
| b_pages | int(4) | NO | | NULL | |
| b_rack | int(5) | NO | | NULL | |
| b_price | decimal(6,2) | NO | | NULL | |
| b_about | text | YES | | NULL | |
+----------+--------------+------+-----+---------+----------------+
Here tbl_books.accid REFERS tbl_book_info.b_acc_id
My query is:
select b_name, b_qty, b_acc_id , (count(*)) Issued, (count(*)) Available
From tbl_book_info
where tbl_book_info.b_acc_id in (select accid from tbl_books
where status = 'I'
GROUP BY status) ;
I want to perform join between the tables 'tbl_book_info' and 'tbl_books' to print the Result as
Desired Output:
+--------+-------+----------+--------+-----------+
| b_name | b_qty | b_acc_id | Issued | Available |
+--------+-------+----------+--------+-----------+
| Java | 3 | 10001 | 2 | 1 |
+--------+-------+----------+--------+-----------+
| Cpp | 5 | 10002 | 3 | 2 |
+--------+-------+----------+--------+-----------+
...(and more)
Output Came:
+--------+-------+----------+--------+-----------+
| b_name | b_qty | b_acc_id | Issued | Available |
+--------+-------+----------+--------+-----------+
| Java | 3 | 10001 | 4 | 4 |
+--------+-------+----------+--------+-----------+

Answer 1

If you want to do a Join, then you should do it, not doing a strange subquery in a where. You can do a Join and a conditional case to sum in two different columns the Issued and the Avalilables
Select a.b_name, a.b_qty, a.b_acc_id , sum(case
when b.status='I' then 1
else 0
end) as Issued,
sum(case
when b.status='A' then 1
else 0
end) as Available
From tbl_book_info a left join tbl_books b on a.b_acc_id=b.accid
group by a.b_name, a.b_qty, a.b_acc_id

Answer 2

In MySQL, you can take a short-cut for this type of query:
select bi.b_name, bi.b_qty, bi.b_acc_id,
sum( b.status = 'I' ) as Issued,
sum( b.status = 'A' ) as Available
from tbl_book_info bi left join
tbl_books b
on bi.b_acc_id = b.accid
group by bi.b_name, bi.b_qty, bi.b_acc_id;
MySQL treats boolean expressions as integers in a numeric context (such as SUM()). Also note that the table aliases are abbreviations for the table name.
With an index on books(acc_id, status), this might be faster using a subqueries:
select bi.b_name, bi.b_qty, bi.b_acc_id,
(select count(*)
from tbl_books b
where b.accid = bi.b_acc_id and
b.status = 'I'
) as Issued,
(select count(*)
from tbl_books b
where b.accid = bi.b_acc_id and
b.status = 'A'
) as Available
from tbl_book_info bi ;
The performance gain is by avoiding the work for the outer group by (typically a sort). The index can be used instead.

Answer 3

I have not tried this solution yet, but I can say that you need to do Group By accid column of tbl_books table. So please make following change in your query:
select b_name, b_qty, b_acc_id , (count(*)) Issued, (count(*)) Available
From tbl_book_info
where tbl_book_info.b_acc_id in (select accid from tbl_books
where status = 'I'
GROUP BY accid) ;