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From:Rick James Date:June 22 2012 11:54pm
Subject:RE: Triggers and column names
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Suggest using a script to read information_schema and construct the TRIGGER.  After all,
the fields are not going to change from one invocation of the trigger to the next, so
don't have the "dynamic" code inside the trigger.

> -----Original Message-----
> From: Hal?sz S?ndor [mailto:hsv@stripped]
> Sent: Thursday, June 21, 2012 5:05 PM
> To: mysql
> Subject: Re: Triggers and column names
> >>>> 2012/06/21 17:06 -0500, Gael Martinez >>>>
> I'm getting that done today thru a large static trigger script and I
> would like something more dynamic...
> <<<<<<<<
> For that it is needful to look up the table in
> INFORMATION_SCHEMA.COLUMNS, and, yes, you can look up the field names--
> but then what will you do with the character strings that are the field
> names? use PREPARE and EXECUTE for the comparisons, being ware of NULL?
> In MySQL help it is written that for its own purposes MySQL actually
> tracks all the information that you crave, but it nowhere is written
> that a BEFORE-UPDATE trigger can make use of it. Maybe UDF, but I know
> naught about that.
> Since BEFORE is called on every attempt, successful or not, maybe AFTER
> would be better.
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Triggers and column namesGael Martinez21 Jun
  • Re: Triggers and column nameshsv22 Jun
    • RE: Triggers and column namesRick James22 Jun
      • Re: Triggers and column namesGael Martinez23 Jun