Mysql-ruby: MysqlField class: "type" instance method

ruby-talk
1

hello
I am writing a tutorial about mysql ruby and I have a question
about the MysqlField class
the method “type” returns the field type. in my examples
it returns a number for example 253 for a field with type VARCHAR.

is it possible to get a more readable representation of this value??

markus

2

Markus Jais info@mjais.de writes:

hello
I am writing a tutorial about mysql ruby and I have a question
about the MysqlField class
the method “type” returns the field type. in my examples
it returns a number for example 253 for a field with type VARCHAR.

is it possible to get a more readable representation of this value??

the types are defined as constants of the MysqlField class. you can build
a lookup-table with something like

types = Hash.new
MysqlField.constants.each { |cname|
cval = MysqlField.const_get(cname)
if (cname =~ /^TYPE_/)
types[cval.to_i] = cname
end
}

after that you have a hash that maps the types to their
constant-names. unfortunately the 253 for TYPE_VAR_STRING is not
defined in the mysql-extension.

the reason for that could be:

(from http://www.mysql.com/doc/en/News-3.21.0.html)

"Changes in release 3.21.0

  • For easier client code, the client should no longer use
    FIELD_TYPE_TINY_BLOB, FIELD_TYPE_MEDIUM_BLOB, FIELD_TYPE_LONG_BLOB
    or FIELD_TYPE_VAR_STRING (as previously returned by
    mysql_list_fields). You should instead only use FIELD_TYPE_BLOB or
    FIELD_TYPE_STRING. If you want exact types, you should use the
    command SHOW FIELDS."

so you should do m.query(“SHOW FIELDS FROM table”) instead of m.list_fields(‘table’)
to get a more readable representation of your metadata, i guess.

have fun
messju

···

markus