A database is composed by one or more tables.

Creating a table in SQL is done using the CREATE TABLE command.

At creation time you need to specify the table columns names, and the type of data they are going to hold.

SQL defines several kinds of data.

The most important and the ones you’ll see more often are:

  • CHAR
  • TEXT
  • VARCHAR
  • DATE
  • TIME
  • DATETIME
  • TIMESTAMP

Numeric types include

  • TINYINT 1 byte
  • INT 4 bytes
  • BIGINT 8 bytes
  • SMALLINT 2 bytes
  • DECIMAL
  • FLOAT

They all hold numbers. What changes is the size that this number can be.

A TINYINT goes goes 0 to 255. An INT from -2^31 to +2^31.

The bigger the size in bytes, the more space will be needed in storage.

This is the syntax to create a people table with 2 columns, one an integer and the other a variable length string:

CREATE TABLE people (
  age INT,
  name CHAR(20)
);