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From:Gerald Clark Date:April 23 2001 2:03pm
Subject:Re: Convert varchar to number field
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Steve Werby wrote:
> 
> "Martin E. Koss" <mek@stripped> wrote:
> > I started a table with a varchar filed of 11 characters for a column that
> > would hold data such as 0.27; 11; 0.6; 1; 5; 7.5; 11.2; etc
> > I wasn't sure if a 'number' field would work. Now I want to list the
> values
> > in this column and they do not list numerically, for example: if we had
> > 0.27; 0.6; 1; 5; 7.5; 11; then 11 would come before 5 and 7.5
> > (alphanumerically).
> >
> > What I need is them to list numerically, so they would list like:
> > 0.27
> > 0.6
> > 1
> > 5
> > 7.5
> > 11
> > 11.2
> >
> > Any advice on what to change the field type to or how to convert it at the
> > time of querying via PHP would be great. Thanks.
> 
> Use an ALTER TABLE statement.  Something like the following:
> 
> ALTER TABLE table_name MODIFY field_name DECIMAL(4,1) UNSIGNED




ALTER TABLE table_name MODIFY old_field_name new_field_name DECIMAL(4,1)
UNSIGNED

Old_field_name and new_field_name can be the same.


> 
> Make sure you choose a numeric type that is appropriate.  See the online
> manual for options.  If you're worried you might ruin your data with this
> conversion first create a copy of the table and experiment on it instead.
> 
> CREATE TABLE my_copy SELECT * FROM original_table
> 
> Note that it won't copy the indexes, but it will create a copy of the table.
> 
> --
> Steve Werby
> President, Befriend Internet Services LLC
> http://www.befriend.com/
> 
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Thread
Convert varchar to number fieldMartin E. Koss20 Apr
  • Re: Convert varchar to number fieldSteve Werby20 Apr
  • Re: Convert varchar to number fieldGerald Clark23 Apr