informix replace null value with 0 in select

c#, informix

Solution

At first you should create simple query with simple db table, some values and requested result that clearly shows your problem.

Part 1: I want replace null value with 0

To change NULL into some value you can use `NVL()` function. Documentation says: The NVL expression returns different results, depending on whether its first argument evaluates to NULL.

Examples:

SELECT fld, NVL(fld, 0) FROM ...

Part 2: and if not null i want to count the data

SELECT COUNT(*) FROM ... WHERE fld IS NOT NULL

Problem

I want replace null value with 0 and if not null i want to count the data ?? ``` sql = "SELECT b.start,COUNT(a.resourceid) " + "FROM t1 b,agentconnectiondetail a "+ "WHERE TO_CHAR(a.startdatetime,'%R') >= TO_CHAR(b.start,'%R') AND TO_CHAR(a.enddatetime,'%R') <= TO_CHAR(b.finish,'%R') " + "AND a.resourceid = '"+dr[1].ToString()+"'" + "GROUP BY 1 ORDER BY 1"; ``` that query output is null what must I do ??

Original source