sql.md

SQL

• relational database: organizes information into one or more tables
• table: collection of data organized into rows and columns
• column: set of data values of a particular type
• row: single record in a table
• common data types are Integer, Text, Date, Real (decimal value)

SQL Statements

• command, always ends with semi-colon
• example:

CREATE TABLE table_name(
  column_1 data_type, 
  column_2 data_type,
  column_3 data_type
  );

Commands

• select data from a database (* = select everything) SELECT * FROM TABLE SELECT TOP 50 PERCENT FROM TABLE
• return only distinct values SELECT DISTINCT column_name FROM table_name
• select data that fulfills criterion SELECT * FROM table WHERE item = "name"
• order by sorts data into ascending order by default, specify DESC for descending order SELECT * FROM table ORDER BY column;
• insert new values into table

  INSERT INTO table_name (column1, column2, column3) 
  VALUES (value1, value2, value3) 
  

• delete DELETE FROM table WHERE column = "value";

User Input

• to get user input, input = getRequestString("User ID");