Please why is this SQlite3 query execution returning "SQLITE BUSY : Database is locked" and what it the likely solution.

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C++

Windows

MFC

SQLite

Please, this code keeps returning "SQLITE BUSY : Database is locked" even though I was not accessing it from another external thread or process and how can I resolve this?

The code uses CppSQLite3 C++ wrapper for SQLite.

int DepartmentAccess::SaveOrDeleteAccess(long long iDeptNameID,long long &iUserID,int &iAccessTypeID)
{
	char szString[1000];
	char chAccessTypeID[1000];

	StringCbPrintfA(szString,sizeof(szString),"%d",iAccessTypeID);
	EncryptString(szString,chAccessTypeID);


	try
	{
		char szDatabaseFile[1000];
		GetDatabaseA(szDatabaseFile,sizeof(szDatabaseFile));
		
		CppSQLite3DB db;
		db.open(szDatabaseFile);

		CppSQLite3Statement stmt = db.compileStatement("SELECT AccessID FROM DepartmentAccess WHERE (InsututionID = ? AND DeptNameID = ? AND UserID = ? AND AccessType = ?)");
		stmt.bind(1,m_iInsututionID);
		stmt.bind(2,iDeptNameID);
		stmt.bind(3,iUserID);
		stmt.bind(4,chAccessTypeID);
		CppSQLite3Query q = stmt.execQuery();
		if(!q.fieldIsNull(0))
		{
			if(!m_iMode)
			{
				return -2;
			}
		}

		if(!m_iMode)
		{
			StringCbCopyA(szString,sizeof(szString),"INSERT INTO DepartmentAccess(InsututionID,DeptNameID,UserID,AccessType) VALUES(?,?,?,?)");
		}
		else
		{
			StringCbCopyA(szString,sizeof(szString),"DELETE FROM DepartmentAccess WHERE (InsututionID = ? AND DeptNameID = ? AND UserID = ? AND AccessType = ?)");
		}
		
		CppSQLite3Statement stmt1 = db.compileStatement(szString);
			
		int iPosition = 1;
		
		stmt1.bind(iPosition++, m_iInsututionID);
		stmt1.bind(iPosition++, iDeptNameID);
		stmt1.bind(iPosition++, iUserID);
		stmt1.bind(iPosition++, chAccessTypeID);
		//Execution gets to this point
		stmt1.execDML();
		//Execution fails to get to this point
		if(!m_iMode)
		{
			StringCbPrintfA(szString,sizeof(szString),"DELETE FROM DepartmentAccessRequest WHERE (InsututionID = ? AND DeptNameID = ? AND UserID = ? AND RequestedAccess = ?)");
			CppSQLite3Statement stmt2 = db.compileStatement(szString);
			int iPosition = 1;
		
			stmt2.bind(iPosition++, m_iInsututionID);
			stmt2.bind(iPosition++, iDeptNameID);
			stmt2.bind(iPosition++, iUserID);
			stmt2.bind(iPosition++, chAccessTypeID);

			stmt2.execDML();
		}
		return 1;
	}
	catch(CppSQLite3Exception & e)
    {
		char szString[200];
		StringCbPrintfA(szString,sizeof(szString),"Error Code: %d\n Error Mesage: %s",e.errorCode(),e.errorMessage());
        MessageBoxA(NULL,szString,"Save Or Delete Access Error(Department Access)",MB_OK);
	}

	return 0;
}