The most stupid things I did as a programmer
The original title of the article: “The * stupidest things I've done in my programming job”, so the translation of the title of the article is not very accurate, but what the author meant by “*” we omit - we do not know for sure :)
I am no longer ashamed of my sins, so go ahead:
Created own ORM ( Object Relational Mapping ) library
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Confusion in the project after two years of support, as a result of hacks-bypasses my ORM library to run direct SQL queries
Use Hibernate , iBATIS , Cayenne or something similar.
Using the Entity-attribute-value model
The lack of scalability (scalability) and the complete inability to run the necessary queries at the database level.
Use the procedure to normalize the database .
Serial access to the database using one common connection for all users.
Zero scalability. Very long response time for 10 or more users working with the application.
Do not do this and use the connection pool. For example c3p0 to reuse connections.
Avoid IDE ( Integrated development environment ), refused to learn and use
The inability to quickly build, test, and deploy (deploy) applications.
Learn IDE: NetBeans , Eclipse etc.
Not used at all.
Corrupted data in applications, including damage to functionality.
Use transactions
Using Statement , string concatenation and naive conversion of requests to "safe".
SQL injections are possible.
Use Prepared Statements , making a valid request depending on the JDBC driver that is used in the application.
All logic is enclosed in an output pattern ( JSP ).
Messy code, inconvenient to maintain
Use the MVC or Front Controller pattern. It is even better to use MVC in the framework of such open-source products like Struts , Spring MVC , and others.
I am no longer ashamed of my sins, so go ahead:
1. ORM
Stupidity
Created own ORM ( Object Relational Mapping ) library
')
The investigation
Confusion in the project after two years of support, as a result of hacks-bypasses my ORM library to run direct SQL queries
What i had to do
Use Hibernate , iBATIS , Cayenne or something similar.
2. EAV
Stupidity
Using the Entity-attribute-value model
The investigation
The lack of scalability (scalability) and the complete inability to run the necessary queries at the database level.
What i had to do
Use the procedure to normalize the database .
3. Database Access
Stupidity
Serial access to the database using one common connection for all users.
The investigation
Zero scalability. Very long response time for 10 or more users working with the application.
What i had to do
Do not do this and use the connection pool. For example c3p0 to reuse connections.
4. IDE
Stupidity
Avoid IDE ( Integrated development environment ), refused to learn and use
The investigation
The inability to quickly build, test, and deploy (deploy) applications.
What i had to do
Learn IDE: NetBeans , Eclipse etc.
5. Transactions
Stupidity
Not used at all.
The investigation
Corrupted data in applications, including damage to functionality.
What i had to do
Use transactions
6. Prepared Statements
Stupidity
Using Statement , string concatenation and naive conversion of requests to "safe".
The investigation
SQL injections are possible.
What i had to do
Use Prepared Statements , making a valid request depending on the JDBC driver that is used in the application.
7. Business logic
Stupidity
All logic is enclosed in an output pattern ( JSP ).
The investigation
Messy code, inconvenient to maintain
What i had to do
Use the MVC or Front Controller pattern. It is even better to use MVC in the framework of such open-source products like Struts , Spring MVC , and others.
Source: https://habr.com/ru/post/67920/
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