parent-child relation with two children...

#11

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#12

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#13

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#14

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#15

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#16

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#17

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#18

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

#19

I hope the real names are not as vague and "meta-data-ish" as
"Entities" and "id" in the real data. Being live and preview are
attributes, if I understand your intent. But Ia m not sure about the
key -- is it version_id or (version_id, version_type), so here is one
guess:

CREATE TABLE Entities
(version_id INTEGER NOT NULL PRIMARY KEY,
version_type CHAR(1) DEFAULT 'P' NOT NULL
CHECK (version_type IN ('P', 'L')),
parent_version_id INTEGER
REFERENCE Entities(version_id)); -- null is first prototype

Quote:

entity (id, live_version_id NULL, preview_version_id NULL)
version (id, parent_entity_id)

where version.parent_entity_id must be a valid entity.id, and that
entity must have the version.id in either live/preview version_id. Is
this a common set up? Does it make sense? Is there a way to express
this requirement at the DB level (I'm specifically using MySQL, but in
general I'd like to know)

Or, did I model my data in a bad way?

Thanks,
Daniel.
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/

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parent-child relation with two children...

comp.databases.theory comp.databases.theory

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM

Re: parent-child relation with two children... - 08-02-2008 , 09:44 AM