What does the "Structured" word means in SQL?
Is it because this(SQL) language statements are organized into Clauses, expressions and predicates?
Because of this organization, is it called "Structured" ?
The original full name was SEQUEL, which stood for "Structured English Query Language". It later had to be renamed to SQL due to trademark issues.
So basically, it was yet another attempt to sell a programming language as "just like English, except with a formal syntax" (hence "structured").
As I understand it, SQL is actually an abbreviation of SEQUEL, or Structured English Query Language. It was meant to have queries that everyone could read. The structured part means that you can only use a structured English; i.e. select col1 from table1, but not give col1 out of table1.
from: http://wiki.answers.com/Q/Why_sql_is_called_structured_query_language
SQL, the standard that was later developed from Codd's work, provides a means of describing data with its natural structure only - that is, without superimposing any additional structure for machine representation purposes.
Mostly because it is a backronym. They needed a S to make Sequel.
来源：https://stackoverflow.com/questions/2938908/what-is-structured-in-structured-query-language