Get the count of records from another table - sql

Question

I have a view that looks like this:
which is defined using this SQL statement:
SELECT
p.p_ccode AS C_CODE,
p.p_pcode AS P_CODE,
p.p_phcode AS PH_CODE,
PO.m_doc_type AS TYPE,
PO.crtime AS DATE
FROM
TABLE1 AS p
LEFT OUTER JOIN
DOCTABLE AS PO ON PO.m_ccode = p.p_ccode
AND PO.m_pcode = p.p_pcode
AND PO.m_phcode = p.p_phcode
Now I want to count the records for another table (TABLE 2) based on the C_CODE, P_CODE and PH_CODE and display it as a column TOTAL in my view.
How can I do this?

Answer 1

one way is to use subquery:
SELECT
p.p_ccode AS C_CODE,
p.p_pcode AS P_CODE,
p.p_phcode AS PH_CODE,
PO.m_doc_type AS TYPE,
PO.crtime AS DATE,
(select count(*) from tale2 t2 where t2.C_CODE = p.p_ccode and t2.P_CODE = p.P_CODE and t2.PH_CODE = p.PH_CODE) as total
FROM TABLE1 AS p
LEFT OUTER JOIN DOCTABLE AS PO
ON PO.m_ccode = p.p_ccode
AND PO.m_pcode = p.p_pcode
AND PO.m_phcode = p.p_phcode

Answer 2

Left join to it, group by and then count --
SELECT
p.p_ccode AS C_CODE,
p.p_pcode AS P_CODE,
p.p_phcode AS PH_CODE,
PO.m_doc_type AS TYPE,
PO.crtime AS DATE,
COUNT(P2.*) AS TOTAL
FROM TABLE1 AS p
LEFT OUTER JOIN DOCTABLE AS PO
ON PO.m_ccode = p.p_ccode
AND PO.m_pcode = p.p_pcode
AND PO.m_phcode = p.p_phcode
LEFT OUTER JOIN TABLE2 AS p2
ON p.m_ccode = p2.p_ccode
AND p.m_pcode = p2.p_pcode
AND p.m_phcode = p2.p_phcode
GROUP BY p.p_ccode, p.p_pcode, p.p_phcode, PO.m_doc_type, PO.crtime

Answer 3

use an CTE (Common Table Expression)
WITH CTE_COUNT
AS(
SELECT
[C_CODE]
,[P_CODE]
,[PH_CODE]
,COUNT(*) AS [TOTAL]
FROM [dbo].[TABLE2]
GROUP BY
[C_CODE]
,[P_CODE]
,[PH_CODE]
)
SELECT
t1.[C_CODE]
,t1.[P_CODE]
,t1.[PH_CODE]
,t1.[TYPE]
,t1.[DATE]
,t2.[TOTAL]
FROM [dbo].[TABLE1] AS t1
LEFT JOIN CTE_COUNT AS t2
ON t2.[C_CODE] = t1.[C_CODE]
AND t2.[P_CODE] = t1.[P_CODE]
AND t2.[PH_CODE] = t1.[PH_CODE]