In my game, an archetype is a collection of associated traits, an attack type, a damage type, and a resource type. Each piece of data is unique to each
archetype. For example, the Mage archetype might look like the following:
archetype: Mage
attack: Targeted Area Effect
damage: Shock
resource: Mana
trait_defense: Willpower
trait_offense: Intelligence
This is the archetype table in SQLite syntax:
create table archetype
(
archetype_id varchar(16) not null,
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_defense_id varchar(16) not null,
trait_offense_id varchar(16) not null,
archetype_description varchar(128),
constraint pk_archetype primary key (archetype_id),
constraint uk_archetype unique (attack_id, damage_id,
resource_type_id,
trait_defense_id,
trait_offense_id)
);
The primary key should be the complete composite, but I do not want to pass
all the data around to other tables unless necessary. For example, there are
crafting skills associated with each archetype which do not need to know any
other archetype data.
An effect is a combat outcome that can be applied to a friend or foe. An effect has an application type (instant, overtime), a type (buff, debuff, harm, heal, etc.) and a detail describing to which stat the effect applies. It also has most of the archetype data to make each effect unique. Also included is the associated trait used for progress and skill checks. For example, an effect might look like:
apply: Instant
type: Harm
detail: Health
archetype: Mage
attack_id: Targeted Area Effect
damage_id: Shock
resource: Mana
trait_id: Intelligence
This is the effect table in SQLite syntax:
create table effect
(
effect_apply_id varchar(16) not null,
effect_type_id varchar(16) not null,
effect_detail_id varchar(16) not null,
archetype_id varchar(16) not null,
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_id varchar(16),
constraint pk_effect primary key(archetype_id, effect_type_id,
effect_detail_id, effect_apply_id,
attack_id, damage_id, resource_type_id),
constraint fk_effect_archetype_id foreign key(archetype_id, attack_id,
damage_id, resource_type_id)
references archetype (archetype_id, attack_id,
damage_id, resource_type_id)
);
An ability is a container that can hold multiple effects. There is no limit to
the kinds of effects it can hold, e.g. having both Mage and Warrior effects in
the same ability, or even having two of the same effects, is fine. Each effect
in the ability is going to have the archetype data, and the effect data.
Again.
Ability tables in SQLite syntax:
create table ability
(
ability_id varchar(64),
ability_description varchar(128),
constraint pk_ability primary key (ability_id)
);
create table ability_effect
(
ability_effect_id integer primary key autoincrement,
ability_id varchar(64) not null,
archetype_id varchar(16) not null,
effect_type_id varchar(16) not null,
effect_detail_id varchar(16) not null,
effect_apply_id varchar(16) not null,
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_id varchar(16),
constraint fk_ability_effect_ability_id foreign key (ability_id)
references ability (ability_id),
constraint fk_ability_effect_effect_id foreign key (archetype_id,
effect_type_id,
effect_detail_id,
effect_apply_id)
references effect (archetype_id,
effect_type_id,
effect_detail_id,
effect_apply_id)
);
This is basically a one to many to many relationship, so I needed a technical
key to have duplicate effects in the ability_effect table.
Questions:
1) Is there a better way to design these tables to avoid the duplication of
data over these three tables?
2) Should these tables be broken down further?
3) Is it better to perform multiple table lookups to collect all the data? For example, just passing around the archetype_id and doing lookups for the data when necessary (which will be often).
UPDATE:
I actually do have parent tables for attacks, damage, etc. I removed those
tables and their related indexes from the sample to make the question clean,
concise, and focused on my duplicate data issue.
I was trying to avoid each table having both an id and a name, as both would be candidate keys and so having both would be wasted space. I was trying to keep the SQLite database as small as possible. (Hence, the many "varchar(16)"
declarations, which I now know SQLite ignores.) It seems in SQLite having both
values is unavoidable, unless being twice as slow is somehow ok when using the
WITHOUT ROWID option during table creation. So, I will rewrite my database to
use ids and names via the rowid implementation.
Thanks for your input guys!
1) Is there a better way to design these tables to avoid the
duplication of data over these three tables?
and also
2) Should these tables be broken down further?
It would appear so.
It would appear Mage is a unique archtype, as is Warrior. (based upon For example, the Mage archetype might look like the following:).
As such why not make the archtype_id a primary key and then reference the attack type, damage etc from tables for these. i.e. have an attack table and a damage table.
So you could, for example, have something like (simplified for demonstration) :-
DROP TABLE IF EXISTS archtype;
DROP TABLE IF EXISTS attack;
DROP TABLE IF EXISTS damage;
CREATE TABLE IF NOT EXISTS attack (attack_id INTEGER PRIMARY KEY, attack_name TEXT, a_more_columns TEXT);
INSERT INTO attack (attack_name, a_more_columns) VALUES
('Targetted Affect','ta blah'), -- id 1
('AOE','aoe blah'), -- id 2
('Bounce Effect','bounce blah') -- id 3
;
CREATE TABLE IF NOT EXISTS damage (damage_id INTEGER PRIMARY KEY, damage_name TEXT, d_more_columns TEXT);
INSERT INTO damage (damage_name,d_more_columns) VALUES
('Shock','shock blah'), -- id 1
('Freeze','freeze blah'), -- id 2
('Fire','fire blah'), -- id 3
('Hit','hit blah')
;
CREATE TABLE IF NOT EXISTS archtype (id INTEGER PRIMARY KEY, archtype_name TEXT, attack_id_ref INTEGER, damage_id_ref INTEGER, at_more_columns TEXT);
INSERT INTO archtype (archtype_name,attack_id_ref,damage_id_ref,at_more_columns) VALUES
('Mage',1,1,'Mage blah'),
('Warrior',3,4,'Warrior Blah'),
('Dragon',2,3,'Dragon blah'),
('Iceman',2,2,'Iceman blah')
;
SELECT archtype_name, damage_name, attack_name FROM archtype JOIN damage ON damage_id_ref = damage_id JOIN attack ON attack_id_ref = attack_id;
Note that the aliases of rowid have been used for id's rather than the name as these are generally the most efficient.
The data for rowid tables is stored as a B-Tree structure containing one entry for each table row, using the rowid value as the key. This means that retrieving or sorting records by rowid is fast. Searching for a record with a specific rowid, or for all records with rowids within a specified range is around twice as fast as a similar search made by specifying any other PRIMARY KEY or indexed value. SQL As Understood By SQLite - CREATE TABLE- ROWIDs and the INTEGER PRIMARY KEY
A rowid is generated for all rows (unless WITHOUT ROWID is specified), by specifying ?? INTEGER PRIMARY KEY column ?? is an alias of the rowid.
Beware using AUTOINCREMENT, unlike other RDMS's that use this for automatically generating unique id's for rows. SQLite by default creates a unique id (the rowid). The AUTOINCREMENT keyword adds a constraint that ensures that the generated id is larger than the highest existing. To do this requires an additional table sqlite_sequence that has to be maintained and interrogated and as such has overheads. The AUTOINCREMENT keyword imposes extra CPU, memory, disk space, and disk I/O overhead and should be avoided if not strictly needed. It is usually not needed. SQLite Autoincrement
The query at the end will result in :-
Now say you wanted types to have multiple attacks and damages per type then the above could easily be adapted by using many-many relationships by introducing reference/mapping/link tables (all just different names for the same). Such a table will have two columns (sometime other columns for data specific to the distinct reference/map/link) one for the parent (archtype) reference/map/link and the other for the child (attack/damage) referenced/mapped/linked.
e.g. the following could be added :-
DROP TABLE IF EXISTS archtype_attack_reference;
CREATE TABLE IF NOT EXISTS archtype_attack_reference
(aar_archtype_id INTEGER NOT NULL, aar_attack_id INTEGER NOT NULL,
PRIMARY KEY(aar_archtype_id,aar_attack_id))
WITHOUT ROWID;
DROP TABLE IF EXISTS archtype_damage_reference;
CREATE TABLE IF NOT EXISTS archtype_damage_reference
(adr_archtype_id INTEGER NOT NULL, adr_damage_id INTEGER NOT NULL,
PRIMARY KEY(adr_archtype_id,adr_damage_id))
WITHOUT ROWID
;
INSERT INTO archtype_attack_reference VALUES
(1,1), -- Mage has attack Targetted
(1,3), -- Mage has attack Bounce
(3,2), -- Dragon has attack AOE
(2,1), -- Warrior has attack targetted
(2,2), -- Warrior has attack AOE
(4,2), -- Iceman has attack AOE
(4,3) -- Icemane has attack Bounce
;
INSERT INTO archtype_damage_reference VALUES
(1,1),(1,3), -- Mage can damage with Shock and Freeze
(2,4), -- Warrior can damage with Hit
(3,3),(3,4), -- Dragon can damage with Fire and Hit
(4,2),(4,4) -- Iceman can damage with Freeze and Hit
;
SELECT archtype_name, attack_name,damage_name FROM archtype
JOIN archtype_attack_reference ON archtype_id = aar_archtype_id
JOIN archtype_damage_reference ON archtype_id = adr_archtype_id
JOIN attack ON aar_attack_id = attack_id
JOIN damage ON adr_damage_id = damage_id
;
The query results in :-
With a slight change the above query could even be used to perform a random attack e.g. :-
SELECT archtype_name, attack_name,damage_name FROM archtype
JOIN archtype_attack_reference ON archtype_id = aar_archtype_id
JOIN archtype_damage_reference ON archtype_id = adr_archtype_id
JOIN attack ON aar_attack_id = attack_id
JOIN damage ON adr_damage_id = damage_id
ORDER BY random() LIMIT 1 -- ADDED THIS LINE
;
You could get :-
Another time you might get :-
3) Is it better to perform multiple table lookups to collect all the
data? For example, just passing around the archetype_id and doing
lookups for the data when necessary (which will be often).
That's pretty hard to say. You may initially think gather all the data once and keep it in memory say as an object. However, at times the underlying data may well already be in memory due to it being cached. Perhaps it could be better to utilise part of each. So I believe the answer is, you will need to test various scenarios.
I would probably avoid those composite primary keys.
And use the more commonly used integer with an autoincrement.
Then add the unique or non-unique composite indexes where needed.
Although i.m.h.o it's not always a bad idea to use a short CHAR or VARCHAR as the primary key in some cases. Mostly when easy to understand abbreviations can be used.
An example. Suppose you have a reference table for Countries. With a primary key on the 2 character CountryCode. Then when querying a table with a foreign key on that CountryCode, then for the human mind it's way easier to understand 'US' than some integer. Even without joining to Countries you'll probably know what Country is referenced.
So here are your tables with a slightly different layout.
create table archetype
(
archetype_id integer primary key autoincrement,
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_defense_id varchar(16) not null,
trait_offense_id varchar(16) not null,
archetype_description varchar(128),
constraint uk_archetype unique (attack_id, damage_id,
resource_type_id,
trait_defense_id,
trait_offense_id)
);
create table effect
(
effect_id integer primary key autoincrement,
archetype_id integer not null, -- FK archetype
effect_apply_id varchar(16) not null,
effect_type_id varchar(16) not null,
effect_detail_id varchar(16) not null,
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_id varchar(16),
constraint pk_effect unique(archetype_id, effect_type_id,
effect_detail_id, effect_apply_id,
attack_id, damage_id, resource_type_id),
constraint fk_effect_archetype_id foreign key(archetype_id)
references archetype (archetype_id)
);
create table ability
(
ability_id integer primary key autoincrement,
ability_description varchar(128)
);
create table ability_effect
(
ability_effect_id integer primary key autoincrement,
ability_id integer not null, -- FK ability
effect_id integer not null, -- FK effect
attack_id varchar(16) not null,
damage_id varchar(16) not null,
resource_type_id varchar(16) not null,
trait_id varchar(16),
constraint fk_ability_effect_ability_id foreign key (ability_id)
references ability (ability_id),
constraint fk_ability_effect_effect_id foreign key (effect_id)
references effect (effect_id)
);
I would like to do analysis of what codes appear in multiple tables under certains conditions. However I don't think the database schema suits the task very well but maybe there's something I don't know about that can help me. Here's a simplified schema:
CREATE TABLE "batchDescription" (
id INTEGER NOT NULL,
name TEXT NOT NULL UNIQUE,
PRIMARY KEY (id)
);
CREATE TABLE "simulationDetails" (
id INTEGER NOT NULL,
ko_index_id INTEGER NOT NULL,
batch_description_id INTEGER NOT NULL,
data1 REAL NOT NULL,
data2 INTEGER NOT NULL,
PRIMARY KEY (id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
FOREIGN KEY(batch_description_id) REFERENCES "batchDescription" (id)
);
CREATE TABLE "koIndex" (
id INTEGER NOT NULL,
number_of_kos INTEGER NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE "1kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
CREATE TABLE "2kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
ko2 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
CREATE TABLE "3kos" (
ko_index_id INTEGER NOT NULL,
ko1 INTEGER NOT NULL,
ko2 INTEGER NOT NULL,
ko3 INTEGER NOT NULL,
PRIMARY KEY (ko_index_id)
FOREIGN KEY(ko_index_id) REFERENCES "koIndex" (id)
);
This goes up to table "525kos" which has ko1 to ko525 in it - ko1 to ko525 are IDs that are primary keys in a table not shown here. I want to do an analysis of how often certain IDs are present under certain conditions. Here is a simple example to illustrate:
I would like to like to count the amount of times a certain ID (let's say 127) (in any koX column) in the "13kos" table occurs when simulationDetails.data1 not equal to 0. I would do this on a database called ko.db from the bash command line like:
for ko_idx in {1..13}; do sqlite3 ko.db "select count(ko${ko_idx}) from '13kos' where ko${ko_idx} = 127 and ko_index_id in (select ko_index_id from simulationDetails where data1 != 0);"; done
Already this is slow and inefficient but is simple compared to what I would like to do. What if I wanted to do an analysis of all the IDs in all possible columns in all "Xkos" tables and compare them to where data1 is equal and not equal to zero?
Can anybody direct me to a better way of doing this or is the schema design just not very good for this kind of analysis and I'll have to give up?
EDIT: Thought I'd add a bit of extra detailto avoid confusion. I suspect that a good way to achieve want I want would be to somehow combine all the "Xkos" tables into one temporary table and then search for certain IDs from that table. How would I combine all 525 ko tables without writing out each table name?
How would I combine all 525 ko tables without writing out each table
name?
Create a table with the same number of columns as the largest table (the table into which you merge) allowing nulls.
query the sqlite_master table using something like :-
SELECT * from sqlite_master WHERE name LIKE '%kos%' AND type = 'table'
Loop through the extracted table names building an INSERT SELECT for each table that will insert the rows from the tables into the table created in 1.
See 2. INSERT INTO table SELECT ...; especially in regard to handling missing columns.
All done, the table created in 1 will be populated accordingly.
I am new to php and sql and I am building a little game to learn a little bit more of the latter.
This is my simple database of three tables:
-- *********** SIMPLE MONSTERS DATABASE
CREATE TABLE monsters (
monster_id VARCHAR(20),
haunt_spawn_point VARCHAR(5) NOT NULL,
monster_name VARCHAR(30) NOT NULL,
level_str VARCHAR(10) NOT NULL,
creation_date DATE NOT NULL,
CONSTRAINT monster_id_pk PRIMARY KEY (monster_id)
);
-- ****************************************
CREATE TABLE spawntypes (
spawn_point VARCHAR(5),
special_tresures VARCHAR (5) NOT NULL,
maximum_monsters NUMBER NOT NULL,
unitary_experience NUMBER NOT NULL,
CONSTRAINT spawn_point_pk PRIMARY KEY (spawn_point)
);
-- ****************************************
CREATE TABLE fights (
fight_id NUMBER,
my_monster_id VARCHAR(20),
foe_spawn_point VARCHAR(5),
foe_monster_id VARCHAR(20) NOT NULL,
fight_start TIMESTAMP NOT NULL,
fight_end TIMESTAMP NOT NULL,
total_experience NUMBER NOT NULL
loot_type NUMBER NOT NULL,
CONSTRAINT my_monster_id_fk FOREIGN KEY (my_monster_id)
REFERENCES monsters (monster_id),
CONSTRAINT foe_spawn_point_fk FOREIGN KEY (foe_spawn_point)
REFERENCES spawntypes (spawn_point),
CONSTRAINT fight_id_pk PRIMARY KEY (fight_id)
);
Given this data how can I easily carry out this two tasks:
1) I would like to create a pl/sql function that passing only a fight_id as a parameter and given the foe_spawn_point (inside the fight table) return the unitary_experience that is related to this spawn point referencing the spawntypes table, how can I do it? :-/ [f(x)]
In order to calculate the total experience earned from a fight (unitary_experience * fight_length) I have created a function that given a particular fight will subtract the fight_end with the fight_start so now I know how long the fight lasted. [f(y)]
2) is it possible to use this two functions (multiply the result that they returns) during the database population task?
INSERT INTO fights VALUES(.... , f(x) * f(y), 'loot A');
in order to populate all the total_experience entries inside the fights table?
thank you for your help
In SQL, you don't generally talk about building functions to do things. The building blocks of SQL are queries, views, and stored procedures (most SQL dialects do have functions, but that is not the place to start).
So, given a variable with $FIGHTID you would fetch the unitary experience with a simple query that uses the join operation:
select unitary_experience
from fight f join
spawnTypes st
on st.spawn_point = f.foe_spawn_point
where fightid = $FIGHTID
If you have a series of values to insert, along with a function, I would recommend using the select form of insert:
insert into fights(<list of columns, total_experience)
select <list of values>,
($FIGHT_END - $FIGHT_START) * (select unitary_experience from spawnTypes where spawnType ='$SPAWN_POINT)
One comment about the tables. It is a good idea for all the ids in the table to be integers that are auto-incremented. In Oracle you do this by creating a sequence (and it is simpler in most other databases).
Are Foreign Keys in SQL Server 2008 are automatically indexed with a value? For Example. if I add a value in my Primary key (or auto incremetend) in may parent table will the table that has a foreign key referenced to that key will automatically have the same value? or I Have to do it explicitly?
No, if you create a foreign key in a child table, it will not automatically get populated when a parent row gets inserted. If you think about this it makes sense. Let's say you have a table like:
CREATE TABLE dbo.Students
(
StudentID INT IDENTITY(1,1) PRIMARY KEY,
Name SYSNAME
);
CREATE TABLE dbo.StudentLoans
(
LoanID INT IDENTITY(1,1) PRIMARY KEY,
StudentID INT FOREIGN KEY REFERENCES dbo.Students(StudentID),
Amount BIGINT -- just being funny
);
What you are suggesting is that when you add a row to Students, the system should automatically add a row to StudentLoans - but what if that student doesn't have a loan? If the student does have a loan, what should the amount be? Should the system pick a random number?
Typically what will happen in this scenario is that you'll be adding a student and their loan at the same time. So if you know the loan amount and the student's name, you can say:
DECLARE
#Name SYSNAME = N'user962206',
#LoanAmount BIGINT = 50000,
#StudentID INT;
INSERT dbo.Students(Name)
SELECT #Name;
SELECT #StudentID = SCOPE_IDENTITY();
INSERT dbo.StudentLoans(StudentID, Amount)
SELECT #StudentID, #LoanAmount;
I have to create a table in sql where one of the columns stores awards for a movie. The schema says it should store something like Oscar, screenplay. Is it possible to store two values in the same field in SQL. If so what datatype would that be and how would you query the table for it?
It's a horrible design pattern to store more than one piece of data in a single column in a relational database. The exact design of your system depends on several things, but here is one possible way to model it:
CREATE TABLE Movie_Awards (
movie_id INT NOT NULL,
award_id INT NOT NULL,
CONSTRAINT PK_Movie_Awards PRIMARY KEY CLUSTERED (movie_id, award_id)
)
CREATE TABLE Movies (
movie_id INT NOT NULL,
title VARCHAR(50) NOT NULL,
year_released SMALLINT NULL,
...
CONSTRAINT PK_Movies PRIMARY KEY CLUSTERED (movie_id)
)
CREATE TABLE Awards (
award_id INT NOT NULL,
ceremony_id INT NOT NULL,
name VARCHAR(50) NOT NULL, -- Ex: Best Picture
CONSTRAINT PK_Awards PRIMARY KEY CLUSTERED (award_id)
)
CREATE TABLE Ceremonies (
ceremony_id INT NOT NULL,
name VARCHAR(50) NOT NULL, -- Ex: "Academy Awards"
nickname VARCHAR(50) NULL, -- Ex: "Oscars"
CONSTRAINT PK_Ceremonies PRIMARY KEY CLUSTERED (ceremony_id)
)
I didn't include Foreign Key constraints here, but hopefully they should be pretty obvious.
Anything's possible; that doesn't mean it's a good idea :)
Far better to normalize your structure and store types like so:
AwardTypes:
AwardTypeID
AwardTypeName
Movies:
MovieID
MovieName
MovieAwardType:
MovieID
AwardTypeID
You can serialize your data in Json format,store Json string, and deselialize on read. More sefer than using your own format
Data presentation does't have to be so close tied with phisical data organisation. Wouldn't it be bether to store these two data in two separate columns and then just do some kind of concatenation at the display time?
It is much less painfull to join data than to split it, if you happen to need just a screenplay, one day...