Your first SELECT

How SELECT, FROM works

• What is SQL?

  SQL (say "sequel" or "S-Q-L") is the language for asking a database for data. Libraries, banks, shops and apps keep their data in databases, and analysts use SQL to get answers out of them.

• What is a table?

  A table is like a sheet with a name: columns with headings, and one row per thing, such as a book or a loan. Every value in a column is the same kind: text, a whole number or a decimal.

• How do I write a SELECT?

  SELECT title, author FROM books;

  List the columns after SELECT, with commas between them, then the table after FROM. The semicolon ends the query.

• What does SELECT * do?

  SELECT * FROM books; shows every column. It's handy for a first look at a table, but in real work list the columns you need: it's clearer and faster.

• Do capital letters matter?

  Not for keywords: select works the same as SELECT. Writing keywords in capitals is a habit that makes queries easier to read.

• How is this like Excel?

  Picking columns is like hiding the ones you don't need, or CHOOSECOLS. The difference: SQL never changes the table, it just shows you a result.