Use dash commenting on sql doc instead

sql.html.markdown

@@ -13,93 +13,93 @@ Several of these sample commands assume that the [MySQL employee sample database
 
 
 ```sql
-# Comments start with a pound sign. End each command with a semicolon.
+-- Comments start with two hyphens. End each command with a semicolon.
 
-# SQL is not case-sensitive about keywords. The sample commands here
+-- SQL is not case-sensitive about keywords. The sample commands here
-# follow the convention of spelling them in upper-case because it makes 
+-- follow the convention of spelling them in upper-case because it makes 
-# it easier to distinguish them from database, table, and column names.
+-- it easier to distinguish them from database, table, and column names.
 
-# Create and delete a database. Database and table names are case-sensitive.
+-- Create and delete a database. Database and table names are case-sensitive.
 CREATE DATABASE someDatabase;
 DROP DATABASE someDatabase;
 
-# List available databases.
+-- List available databases.
 SHOW DATABASES;
 
-# Use a particular existing database. 
+-- Use a particular existing database. 
 USE employees;    
 
-# Select all rows and columns from the current database's departments table.
+-- Select all rows and columns from the current database's departments table.
-# Default activity is for the interpreter to scroll the results on your screen. 
+-- Default activity is for the interpreter to scroll the results on your screen. 
 SELECT * FROM departments;
 
-# Retrieve all rows from the departments table, 
+-- Retrieve all rows from the departments table, 
-# but only the dept_no and dept_name columns. 
+-- but only the dept_no and dept_name columns. 
-# Splitting up commands across lines is OK.
+-- Splitting up commands across lines is OK.
 SELECT dept_no,
        dept_name FROM departments;
 
-# Retrieve all departments columns, but just 5 rows. 
+-- Retrieve all departments columns, but just 5 rows. 
 SELECT * FROM departments LIMIT 5;
 
-# Retrieve dept_name column values from the departments
+-- Retrieve dept_name column values from the departments
-# table where the dept_name value has the substring "en". 
+-- table where the dept_name value has the substring "en". 
 SELECT dept_name FROM departments WHERE dept_name LIKE "%en%";
 
-# Retrieve all columns from the departments table where the dept_name
+-- Retrieve all columns from the departments table where the dept_name
-# column starts with an "S" and has exactly 4 characters after it. 
+-- column starts with an "S" and has exactly 4 characters after it. 
 SELECT * FROM departments WHERE dept_name LIKE "S____";
 
-# Select title values from the titles table but don't show duplicates.
+-- Select title values from the titles table but don't show duplicates.
 SELECT DISTINCT title FROM titles;
 
-# Same as above, but sorted (case-sensitive) by the title values. 
+-- Same as above, but sorted (case-sensitive) by the title values. 
 SELECT DISTINCT title FROM titles ORDER BY title;
 
-# Show the number of rows in the departments table.
+-- Show the number of rows in the departments table.
 SELECT COUNT(*) FROM departments;
 
-# Show the number of rows in the departments table that
+-- Show the number of rows in the departments table that
-# have "en" as a substring of the dept_name value. 
+-- have "en" as a substring of the dept_name value. 
 SELECT COUNT(*) FROM departments WHERE dept_name LIKE "%en%";
 
-# A JOIN of information from multiple tables: the titles table shows 
+-- A JOIN of information from multiple tables: the titles table shows 
-# who had what job titles, by their employee numbers, from what 
+-- who had what job titles, by their employee numbers, from what 
-# date to what date. Retrieve this information, but instead of the
+-- date to what date. Retrieve this information, but instead of the
-# employee number, use the employee number as a cross-reference to 
+-- employee number, use the employee number as a cross-reference to 
-# the employees table to get each employee's first and last name
+-- the employees table to get each employee's first and last name
-# instead. (And only get 10 rows.)
+-- instead. (And only get 10 rows.)
 
 SELECT employees.first_name, employees.last_name,
        titles.title, titles.from_date, titles.to_date
 FROM titles INNER JOIN employees ON
        employees.emp_no = titles.emp_no LIMIT 10;
 
-# List all the tables in all the databases. Implementations typically provide
+-- List all the tables in all the databases. Implementations typically provide
-# their own shortcut command to do this with the database currently in use.
+-- their own shortcut command to do this with the database currently in use.
 SELECT * FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_TYPE='BASE TABLE';
 
-# Create a table called tablename1, with the two columns shown, for
+-- Create a table called tablename1, with the two columns shown, for
-# the database currently in use. Lots of other options are available
+-- the database currently in use. Lots of other options are available
-# for how you specify the columns, such as their datatypes.
+-- for how you specify the columns, such as their datatypes.
 CREATE TABLE tablename1 (`fname` VARCHAR(20),`lname` VARCHAR(20));
 
-# Insert a row of data into the table tablename1. This assumes that the 
+-- Insert a row of data into the table tablename1. This assumes that the 
-# table has been defined to accept these values as appropriate for it. 
+-- table has been defined to accept these values as appropriate for it. 
 INSERT INTO tablename1 VALUES('Richard','Mutt');
 
-# In tablename1, change the fname value to "John"
+-- In tablename1, change the fname value to "John"
-# for all rows that have an lname value of "Mutt". 
+-- for all rows that have an lname value of "Mutt". 
 UPDATE tablename1 SET fname="John" WHERE lname="Mutt";
 
-# Delete rows from the tablename1 table
+-- Delete rows from the tablename1 table
-# where the lname value begins with "M".
+-- where the lname value begins with "M".
 DELETE FROM tablename1 WHERE lname like "M%";
 
-# Delete all rows from the tablename1 table, leaving the empty table.
+-- Delete all rows from the tablename1 table, leaving the empty table.
 DELETE FROM tablename1;
 
-# Remove the entire tablename1 table. 
+-- Remove the entire tablename1 table. 
 DROP TABLE tablename1;
 ```