According to the trace flag 1204 report, the following two queries are causing the deadlock:

1. Simple insert statement
INSERT INTO TABLE1 (FIELD1, FIELD2, FIELD3) VALUES (@INTVAL, @NTEXTVAL, @CHARVAL)
– Provide IX lock

2. Simple select statement with READPAST
SELECT FIELD1, FIELD2, FIELD3 FROM TABLE1 WITH READPAST WHERE FIELD1 > @VALUE
– Provide S lock

The above queries handle online transactions. One service will only run the insert statement and the other service will only run the select statement. This deadlock error happens intermittently.

I’m wondering if this deadlock happens because FIELD2 is a ntext field? If I’m using NOLOCK in the SELECT statement, would it be possible that I may miss retrieving FIELD2 information since it is the ntext field that keeps data in a separate page?

TRANSDETAILSTABLE
TransRef_VC(15) PK – the primary key to store the voucher No.
TransDate_DT – this will store the date of transaction
Particulars_VC(200) – this will store the explanation of transaction

TRANSACTIONTABLE
TransEntryNum(BigInt) PK -the primary key, autoincrement
TransRef_VC(15) FK -the foreign key, this will store the voucher no.
GLCode_CH(10) (FK) -the account code such as 1010010000 for CASH
TransAmount_MN -the amount of transaction, positive for debit and negative for credit

GLTABLE
GLCode_CH(10) (PK) -primary key to hold code of accounts
GLDescription_VC(75) -the accounts description such as CASH, ACCOUNTS
RECEIVABLES, etc.

Below is a sample transaction

Transaction Reference Number: CR12345

Transaction Date: 12/14/2008

GLCode GL Description Debit Credit
———– ——————— ————– ————–
1010010000 CASH 1,500.00
1050020000 Sales Discount 30.00
1050010000 SALES 1,500.00

Particulars: To record cash sales from customers.

I created a function under the Class as follows

Public Sub AddTransaction(ByVal myTransTable As DataTable, ByVal iret As Integer)

I have strConnectionString declared.

Dim myConnection As sqlConnection = New SqlConnection(strConnectionString)
Dim cmdAddTransEntry, cmdAddTransRef As SqlCommand
Dim ParamTransRef, ParamRef, ParamTransDate, ParamParticulars, ParamUserID, ParamGLCode, ParamSLCode, ParamTransAmount, ParamTransCat As SqlParameter
Dim myTrans As SqlTransaction
Dim strAddTrans As String

myConnection.Open()
myTrans = myConnection.BeginTransaction

Try
strAddTrans = “INSERT INTO TransactionDetailsTable(TransRef, TransDate, TransParticulars)” & _
“VALUES(@TransRef, @TransDate, @TransParticulars)”
cmdAddTransRef = New SqlCommand(strAddTrans, myConnection)
cmdAddTransRef.Transaction = myTrans

ParamTransRef = cmdAddTransRef.Parameters.Add(”@TransRef”, SqlDbType.VarChar, 16)
ParamTransDate = cmdAddTransRef.Parameters.Add(”@TransDate”, SqlDbType.SmallDateTime, 8)
ParamParticulars = cmdAddTransRef.Parameters.Add(”@TransParticulars”, SqlDbType.VarChar, 300)

ParamTransRef.Value = VoucherNo ‘came from class
ParamTransDate.Value = dtSystemDate ‘dtSystemDate is a variable given under Global
Module
ParamParticulars.Value = Particulars ‘came from class
cmdAddTransRef.ExecuteNonQuery()

strAddTrans = “INSERT INTO TransEntryTable(TransRef, GLCode, SLCode, TransAmount)” & _
“VALUES(@TransRef, @GLCode, @SLCode, @TransAmount)”

cmdAddTransEntry = New SqlCommand(strAddTrans, myConnection)
cmdAddTransEntry.Transaction = myTrans

Dim TAmount As Double = 0

For i = 0 To myTransTable.Rows.Count – 1 ‘ Came from Dataset

‘to determine if debit or credit and if credit make it negative(-)
If Not IsNumeric(myTransTable.Rows(i)(2)) Then
TAmount = myTable.Rows(i)(3) * (-1)
Else
TAmount = myTable.Rows(i)(2)
End If

ParamRef = cmdAddTransEntry.Parameters.Add(”@TransRef”, SqlDbType.VarChar, 16)
ParamGLCode = cmdAddTransEntry.Parameters.Add(”@GLCode”, SqlDbType.Char, 10)
ParamTransAmount = cmdAddTransEntry.Parameters.Add(”@TransAmount”, SqlDbType.Money, 10)

ParamRef.Value = VoucherNo
ParamGLCode.Value = myTable.Rows(i)(0)
ParamTransAmount.Value = TAmount
cmdAddTransEntry.ExecuteNonQuery()
Next

myTrans.Commit()

Catch ex As Exception

myTrans.Rollback()
MsgBox(”Transaction Not Added”)

Finally
myConnection.Close()
End Try

End Sub

executing this will return error as follows under cmdAddTransEntry.ExecuteQuery()

The variable name ‘@TransRef’ has already been declared. Variable names must be
unique within a query batch or stored procedure.

I observed that i just encountered an error for the 2nd iteration of the for each loop.

Please help me solve this problem.

Thanks in advance and more power