The document contains information about SQL functions organized into multiple chapters. Chapter 1 discusses basic SQL queries using SELECT statements and operators like arithmetic operators, concatenation, aliases and DISTINCT. Chapter 2 covers the WHERE clause and comparison operators as well as NULL values, BETWEEN, IN, LIKE and logical operators. Chapter 3 describes different categories of single row functions including character functions like UPPER, LOWER, INITCAP as well as number functions like ROUND and TRUNC, and date functions for performing calculations on dates.