fundamentals/database/notes/07-groupby-functions-worksheet.md

# Queries

## Aggregation
1. Get the maximum IQ in all students (Try without aggregation first).

```sql
```

2. Get the maximum IQ in all students (With aggregation).

```sql
```

3. Get the oldest batch from the batches table.

```sql
```

4. Fetch the number of batches that start with the word `Jedi`.

```sql
```

5. Get the average IQ of all students (Without using `AVG`)

```sql
```

6. Get the average IQ of students in all batches.

```sql
```
7. Find the average IQ of students in each batch.

```sql
```

8. Find the total number of students in each batch.

```sql
```

9. Get the total number of batches taught by each instructor.

```sql
```

10. Find the average IQ of students in batches with batch ID `1` and `2`.

```sql
```

11. Find count of students that are part of batches that have average IQ greater than `120`.

```sql
```

## Built-in Functions
1. Get the average IQ of all the students rounded to the nearest integer.

```sql

```
2. Find all batches whose name is longer than 10 characters.

```sql

```

3. Find all batches whose name's first 10 characters contains the string `sher`

```sql

```

4. Get all batches that have started on a Sunday

```sql

```

5. Get all batches that have been running for more than 10 years

```sql

```
6. Print the name and the instructor's id for each batch. If no instructor is assigned, print `NO INSTRUCTOR`.

```sql

```

7. Print the name and IQ of each student. If the IQ of the student is less than 100, print `LOW IQ` instead.

```sql

```

8. For each student print the name and their IQ category.

| IQ        | Category |
| --------- | -------- |
| < 100     | LOW IQ   |
| 100 - 150 | MEDIUM   |
| > 150     | HIGH     |

```sql

```