---
# System prepended metadata

title: Week 2 (Nov 23rd - Nov 27th 2020)

---

# 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