# Week 2 (Nov 23rd - Nov 27th 2020)

## Wednesday Nov 25th

- Do query with selection

SELECT DISTINCT column, another_column, …
FROM mytable
WHERE condition(s);

- ORDER BY {Column Name} ASC/DESC

- Use LIMIT and OFFSET

SELECT column, another_column, …
FROM mytable
WHERE condition(s)
ORDER BY column ASC/DESC
LIMIT num_limit OFFSET num_offset;

- Join data for query involved multiple tables

SELECT column, another_table_column, …
FROM mytable
INNER JOIN another_table 
    ON mytable.id = another_table.id
WHERE condition(s)
ORDER BY column, … ASC/DESC
LIMIT num_limit OFFSET num_offset;

- Different ways to JOIN

SELECT column, another_column, …
FROM mytable
INNER/LEFT/RIGHT/FULL JOIN another_table 
    ON mytable.id = another_table.matching_id
WHERE condition(s)
ORDER BY column, … ASC/DESC
LIMIT num_limit OFFSET num_offset;

- Group by

SELECT group_by_column, AGG_FUNC(column_expression) AS aggregate_result_alias, …
FROM mytable
WHERE condition
GROUP BY column
HAVING group_condition;

- Subquery

SELECT column_names
FROM table_names
WHERE value IN
  (SELECT column_names
  FROM other_table
  WHERE condition)

## Thursday Nov 26th

### Morning

### Afternoon