1. SQL 101
2nd Session

2. Functions:
- Character functions  today
- Number functions
- Single Row functions

3. Character Functions:
LOWER UPPER
INITCAP LPAD
RPAD LTRIM
RTRIM TRIM
SUBSTR INSTR
LENGTH in WHERE & GROUP BY clauses
Nested functions Concatenation
REPLACE TRANSLATE
SOUNDEX

4. Single-Row Functions:
NVL COALESCE
NVL2 LNNVL
NULLIF NANVL
DECODE Searched CASE
Simple CASE

5. Number Functions:
ABS SIGN
ROUND TRUNC
FLOOR CEIL
MOD REMAINDER
Floating point numbers Arithmetic operators

6. Character functions....
UPPER(char)
LOWER(char)
INITCAP(char)
LPAD(char1, n [, char2])
RPAD(char1, n [, char2])
SELECT state, LOWER(state), LOWER('State')
FROM zipcode;
SELECT UPPER(city) as "Upper Case City", state, INITCAP(state)
WHERE zip = '10035';
SELECT RPAD(city, 20, '*') as "City Name",
LPAD(state, 10, '-') as "State Name"

7. A single row is always returned in the result set.
Character functions....
The DUAL table
Character functions....
The DUAL table contains a single row and a single column called DUMMY. It’s often used with functions to select values that do not exist in tables such as today’s date.
A single row is always returned in the result set.
This table is owned by SYS and is available to all users.
SELECT * from dual;

8. SELECT TRIM(LEADING '0' FROM '0001234500') leading,
Character functions....
LTRIM(char1 [, char2])
RTRIM(char1 [, char2])
TRIM([LEADING|TRAILING|BOTH] char1
FROM char2)
TRIM(char2)
SUBSTR(char1, start_pos [, substr_length])
SELECT LTRIM(' ', '0') left,
RTRIM(' ', '0') right,
LTRIM(RTRIM(' ', '0'), '0') both
FROM dual;
SELECT TRIM(LEADING '0' FROM ' ') leading,
TRIM(TRAILING '0' FROM ' ') trailing,
TRIM('0' FROM ' ') both
Column "1-5" format a6
Column "6 only" format a6
SELECT last_name,
SUBSTR(last_name, 1, 5) as "1-5",
SUBSTR(last_name, 6) as "6 only"
FROM student;

9. Column description format a30 Column "er" format 999
Character functions....
INSTR(char1, char2 [,start_pos [, occurrence]])
LENGTH(char1)
Column description format a30
Column "er" format 999
SELECT description, INSTR(description, 'er') "er"
FROM course;
SELECT LENGTH('Hello there')
FROM dual;
SELECT first_name, last_name
FROM student
WHERE SUBSTR(last_name, 1, 2) = 'Mo';

10. WHERE and GROUP BY clauses:
SELECT first_name, last_name
FROM student
WHERE INSTR(first_name, '.') > 0
ORDER BY LENGTH(last_name);
Nested Functions:
Column mi format a3
Column first format a10
SELECT first_name,
SUBSTR(first_name, INSTR(first_name, '.') -1) mi,
SUBSTR(first_name, 1, INSTR(first_name, '.') -2) first
WHERE INSTR(first_name, '.') >= 3;

11. Concatenation: SELECT CONCAT(city, state) FROM zipcode;
SELECT city||state||zip
SELECT city||', '||state||' '||zip

12. SELECT REPLACE('My hand is asleep', 'hand', 'foot') FROM dual;
Character functions....
REPLACE(char, if, then)
TRANSLATE(char, if, then)
SELECT REPLACE('My hand is asleep', 'hand', 'foot')
FROM dual;
SELECT REPLACE('My hand is asleep', 'X', 'foot')
SELECT phone
FROM student
WHERE TRANSLATE(phone, ' ','##########') <> '###-###-####';
WHERE TRANSLATE(phone, ' ','##########') <> '###-###-####';

13. Soundex: SELECT student_id, last_name FROM student
WHERE SOUNDEX(last_name) = SOUNDEX('Torch');
Just my 2cents.... This function is crap.... Don't ever use BUT, know it exists.