log4net inserting (null) into custom column

问题

Added a custom column as suggested here. Things are working fine when ever I log something into this column using the code line

log4net.GlobalContext.Properties["CustomColumn"] = "Custom value";

But if I pass null instead as below

log4net.GlobalContext.Properties["CustomColumn"] = null;

this is logged as (null)(a string null included in brakets). This also happens if I do not log at all, like I comment the code as shown below.

//log4net.GlobalContext.Properties["CustomColumn"] = null;

So the question is, is there a way to make it actually null in the database, instead of a string - (null). I am using ms sql server 2008 r2

回答1:

try this

log4net.GlobalContext.Properties["CustomColumn"] = DBNull.Value;

回答2:

I have modified the insert statement of the commandText value in Web.config file to

"INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[Exception],[BrowserCapabilities]) VALUES (@log_date, @thread, @log_level, 
        @logger, @message, @exception, CASE WHEN @BrowserCapabilities = '' OR @BrowserCapabilities = '(null)' THEN NULL ELSE @BrowserCapabilities END )"

Now this works fine.

回答3:

I prefer "NULLIF" over "CASE WHEN" in this case. This alternative still requires modifying the insert statement of the commandText value in the Web.config file, but it is more efficient:

INSERT INTO Log ([Date],[Thread],[Level],[Logger],[Message],[Exception],[BrowserCapabilities]) 
VALUES (@log_date,@thread,@log_level,@logger,@message,@exception,NULLIF(@BrowserCapabilities,'(null)')"

来源：https://stackoverflow.com/questions/28964934/log4net-inserting-null-into-custom-column

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logging

log4net