Rails 4: List of available datatypes

Where can I find a list of data types that can be used in Ruby on Rails 4? Such as

text

string

integer

float

date

I keep learning about new ones and I'd love to have a list I could easily refer to.

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Here are all the Rails 4 (ActiveRecord migration) datatypes:

:binary

:boolean

:date

:datetime

:decimal

:float

:integer

:bigint

:primary_key

:references

:string

:text

:time

:timestamp

Source: http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_column
These are the same as with Rails 3.

If you use PostgreSQL, you can also take advantage of these:

:hstore

:json

:jsonb

:array

:cidr_address

:ip_address

:mac_address

They are stored as strings if you run your app with a not-PostgreSQL database.

Edit, 2016-Sep-19:

There's a lot more postgres specific datatypes in Rails 4 and even more in Rails 5.

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You might also find it useful to know generally what these data types are used for:

:string - is for small data types such as a title. (Should you choose string or text?)

:text - is for longer pieces of textual data, such as a paragraph of information

:binary - is for storing data such as images, audio, or movies.

:boolean - is for storing true or false values.

:date - store only the date

:datetime - store the date and time into a column.

:time - is for time only

:timestamp - for storing date and time into a column.(What's the difference between datetime and timestamp?)

:decimal - is for decimals (example of how to use decimals).

:float - is for decimals. (What's the difference between decimal and float?)

:integer - is for whole numbers.

:primary_key - unique key that can uniquely identify each row in a table

There's also references used to create associations. But, I'm not sure this is an actual data type.

New Rails 4 datatypes available in PostgreSQL:

:hstore - storing key/value pairs within a single value (learn more about this new data type)

:array - an arrangement of numbers or strings in a particular row (learn more about it and see examples)

:cidr_address - used for IPv4 or IPv6 host addresses

:inet_address - used for IPv4 or IPv6 host addresses, same as cidr_address but it also accepts values with nonzero bits to the right of the netmask

:mac_address - used for MAC host addresses

Learn more about the address datatypes here and here.

Also, here's the official guide on migrations: http://edgeguides.rubyonrails.org/migrations.html

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It is important to know not only the types but the mapping of these types to the database types, too:

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Source added - Agile Web Development with Rails 4

链接地址: http://www.djcxy.com/p/25114.html

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