filed showing null value when joining table - mysql

Question

below is my query
select C.cName,DATE_FORMAT(CT.dTransDate,'%d-%M-%Y') as dTransDate,
(c.nOpBalance+IFNULL(CT.nAmount,0)) AS DrAMount,IFNULL(CTR.nAmount,0) AS
CrAMount,((c.nOpBalance+IFNULL(CT.nAmount,0))-IFNULL(CTR.nAmount,0)) AS
Balance,CT.cTransRefType,CT.cRemarks,cinfo.cCompanyName,cinfo.caddress1,cinfo.cP
honeOffice,cinfo.cMobileNo,cinfo.cEmailID,cinfo.cWebsite from Customer
C LEFT JOIN Client_Transaction CT ON CT.nClientPk = C.nCustomerPk AND
CT.cTransRefType='PAYMENT' AND CT.cClientType='CUSTOMER' AND CT.dTransDate
between '' AND '' LEFT JOIN Client_Transaction CTR ON CTR.nClientPk =
C.nCustomerPk AND CTR.cTransRefType='RECEIPT' AND
CTR.cClientType='CUSTOMER' AND CTR.dTransDate between '2015-05-01' AND
'2015-05-29' LEFT JOIN companyinfo cinfo ON cinfo.cCompanyName like
'%Fal%' Where C.nCustomerPk = 4 Order By dTransDate
it's showing all value but dTransDate ,cTransRefType,cRemarks, showing null.

Answer 1

One obvious thing jumps out at us:
CT.dTransDate BETWEEN '' AND ''
^^ ^^
Another thing that jumps out at us is that there's a semi-Cartesian join between rows from CT and rows from CTR. If 5 rows are returned from CT for a given customer, and 5 rows are returned from CTR, that's going to produce a total of 5*5 = 25 rows. That just doesn't seem like a resultset that you'd really want returned.
Also, if more than one row is returned from cinfo, that's also going to cause another semi-Cartesian join. If there's two rows returned from cinfo, the total number or rows in the resultset will be doubled. It's valid to do that in SQL, but this is an unusual pattern.
The calculation of the balance is also very strange. For each row, the nAmount is added/subtracted from opening balance. On the next row, the same thing, on the original opening balance. There's nothing invalid SQL-wise with doing that, but the result being returned just seems bizarre. (It seems much more likely that you'd want to show a running balance, with each transaction.)
Another thing that jumps out at us is that you are ordering the rows by a string representation of a DATE, with the day as the leading portion. (As long as all the rows have date values in the same year and month, that will probably work, but it just seems bizarre that we wouldn't sort on the DATE value, or a canonical string representation.
I strongly suspect that you want to run a query that's more like this. (This doesn't do a "running balance" calculation. It does return the 'PAYMENT' and 'RECEIPT' rows as individual rows, without producing a semi-Cartesian result.
SELECT c.cName
, DATE_FORMAT(t.dTransDate,'%d-%M-%Y') AS dTransDate
, C.nOpBalance
, IF(t.cTransRefType='PAYMENT',IFNULL(t.nAmount,0),0) AS DrAMount
, IF(t.cTransRefType='RECEIPT',IFNULL(t.nAmount,0),0) AS CrAMount
, t.cTransRefType
, t.cRemarks
, ci.*
FROM Customer c
LEFT
JOIN Client_Transaction t
ON t.nClientPk = c.nCustomerPk
AND t.cClientType = 'CUSTOMER'
AND t.dTransDate >= '2015-05-01'
AND t.dTransDate <= '2015-05-29'
AND t.cTransRefType IN ('PAYMENT','RECEIPT')
CROSS
JOIN ( SELECT cinfo.cCompanyName
, cinfo.caddress1
, cinfo.cPhoneOffice
, cinfo.cMobileNo
, cinfo.cEmailID
, cinfo.cWebsite
FROM companyinfo cinfo
WHERE cinfo.cCompanyName LIKE '%Fal%'
ORDER BY cinfo.cCompanyName
LIMIT 1
) ci
WHERE c.nCustomerPk = 4
ORDER BY t.dTransDate, t.cTransRefTpye, t.id