Do you know a good source to learn how to design SQL solutions?
Beyond the basic language syntax, I'm looking for something to help me understand:
This question is related to
sql
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database-design
scalability
Experience counts for a lot, but in terms of table design you can learn a lot from how ORMs like Hibernate and Grails operate to see why they do things. In addition:
Keep different types of data separate - don't store addresses in your order table, link to an address in a separate addresses table, for example.
I personally like having an integer or long surrogate key on each table (that holds data, not those that link different tables together, e,g., m:n relationships) that is the primary key.
I also like having a created and modified timestamp column.
Ensure that every column that you do "where column = val" in any query has an index. Maybe not the most perfect index in the world for the data type, but at least an index.
Set up your foreign keys. Also set up ON DELETE and ON MODIFY rules where relevant, to either cascade or set null, depending on your object structure (so you only need to delete once at the 'head' of your object tree, and all that object's sub-objects get removed automatically).
If you want to modularise your code, you might want to modularise your DB schema - e.g., this is the "customers" area, this is the "orders" area, and this is the "products" area, and use join/link tables between them, even if they're 1:n relations, and maybe duplicate the important information (i.e., duplicate the product name, code, price into your order_details table). Read up on normalisation.
Someone else will recommend exactly the opposite for some or all of the above :p - never one true way to do some things eh!
These are questions which, in my opionion, requires different knowledge from different domains.
That said, maybe you want to read some books, personally I've used this book in my datbase university course (and found a decent one, but I've not read other books in this field, so my advice is to check out for some good books in database design).
These are questions which, in my opionion, requires different knowledge from different domains.
That said, maybe you want to read some books, personally I've used this book in my datbase university course (and found a decent one, but I've not read other books in this field, so my advice is to check out for some good books in database design).
I really liked this article.. http://www.codeproject.com/Articles/359654/important-database-designing-rules-which-I-fo
It's been a while since I read it (so, I'm not sure how much of it is still relevant), but my recollection is that Joe Celko's SQL for Smarties book provides a lot of info on writing elegant, effective, and efficient queries.
Experience counts for a lot, but in terms of table design you can learn a lot from how ORMs like Hibernate and Grails operate to see why they do things. In addition:
Keep different types of data separate - don't store addresses in your order table, link to an address in a separate addresses table, for example.
I personally like having an integer or long surrogate key on each table (that holds data, not those that link different tables together, e,g., m:n relationships) that is the primary key.
I also like having a created and modified timestamp column.
Ensure that every column that you do "where column = val" in any query has an index. Maybe not the most perfect index in the world for the data type, but at least an index.
Set up your foreign keys. Also set up ON DELETE and ON MODIFY rules where relevant, to either cascade or set null, depending on your object structure (so you only need to delete once at the 'head' of your object tree, and all that object's sub-objects get removed automatically).
If you want to modularise your code, you might want to modularise your DB schema - e.g., this is the "customers" area, this is the "orders" area, and this is the "products" area, and use join/link tables between them, even if they're 1:n relations, and maybe duplicate the important information (i.e., duplicate the product name, code, price into your order_details table). Read up on normalisation.
Someone else will recommend exactly the opposite for some or all of the above :p - never one true way to do some things eh!
I started out with this article
http://en.tekstenuitleg.net/articles/software/database-design-tutorial/intro.html
It's pretty concise compared to reading an entire book and it explains the basics of database design (normalization, types of relationships) very well.
It's been a while since I read it (so, I'm not sure how much of it is still relevant), but my recollection is that Joe Celko's SQL for Smarties book provides a lot of info on writing elegant, effective, and efficient queries.
Head First SQL is a great introduction.
I really liked this article.. http://www.codeproject.com/Articles/359654/important-database-designing-rules-which-I-fo
Head First SQL is a great introduction.
These are questions which, in my opionion, requires different knowledge from different domains.
That said, maybe you want to read some books, personally I've used this book in my datbase university course (and found a decent one, but I've not read other books in this field, so my advice is to check out for some good books in database design).
Head First SQL is a great introduction.
It's been a while since I read it (so, I'm not sure how much of it is still relevant), but my recollection is that Joe Celko's SQL for Smarties book provides a lot of info on writing elegant, effective, and efficient queries.
Experience counts for a lot, but in terms of table design you can learn a lot from how ORMs like Hibernate and Grails operate to see why they do things. In addition:
Keep different types of data separate - don't store addresses in your order table, link to an address in a separate addresses table, for example.
I personally like having an integer or long surrogate key on each table (that holds data, not those that link different tables together, e,g., m:n relationships) that is the primary key.
I also like having a created and modified timestamp column.
Ensure that every column that you do "where column = val" in any query has an index. Maybe not the most perfect index in the world for the data type, but at least an index.
Set up your foreign keys. Also set up ON DELETE and ON MODIFY rules where relevant, to either cascade or set null, depending on your object structure (so you only need to delete once at the 'head' of your object tree, and all that object's sub-objects get removed automatically).
If you want to modularise your code, you might want to modularise your DB schema - e.g., this is the "customers" area, this is the "orders" area, and this is the "products" area, and use join/link tables between them, even if they're 1:n relations, and maybe duplicate the important information (i.e., duplicate the product name, code, price into your order_details table). Read up on normalisation.
Someone else will recommend exactly the opposite for some or all of the above :p - never one true way to do some things eh!
Head First SQL is a great introduction.
I started out with this article
http://en.tekstenuitleg.net/articles/software/database-design-tutorial/intro.html
It's pretty concise compared to reading an entire book and it explains the basics of database design (normalization, types of relationships) very well.
These are questions which, in my opionion, requires different knowledge from different domains.
That said, maybe you want to read some books, personally I've used this book in my datbase university course (and found a decent one, but I've not read other books in this field, so my advice is to check out for some good books in database design).
Experience counts for a lot, but in terms of table design you can learn a lot from how ORMs like Hibernate and Grails operate to see why they do things. In addition:
Keep different types of data separate - don't store addresses in your order table, link to an address in a separate addresses table, for example.
I personally like having an integer or long surrogate key on each table (that holds data, not those that link different tables together, e,g., m:n relationships) that is the primary key.
I also like having a created and modified timestamp column.
Ensure that every column that you do "where column = val" in any query has an index. Maybe not the most perfect index in the world for the data type, but at least an index.
Set up your foreign keys. Also set up ON DELETE and ON MODIFY rules where relevant, to either cascade or set null, depending on your object structure (so you only need to delete once at the 'head' of your object tree, and all that object's sub-objects get removed automatically).
If you want to modularise your code, you might want to modularise your DB schema - e.g., this is the "customers" area, this is the "orders" area, and this is the "products" area, and use join/link tables between them, even if they're 1:n relations, and maybe duplicate the important information (i.e., duplicate the product name, code, price into your order_details table). Read up on normalisation.
Someone else will recommend exactly the opposite for some or all of the above :p - never one true way to do some things eh!
Source: Stackoverflow.com