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

# Queries

## Sub-queries

1. Get all the students whose IQ is greater than the average IQ.

```sql

```

2. Get all the students whose IQ is greater than the highest IQ of the batch_id `2` students.

```sql

```

3. Get all the students whose IQ is greater than `all` the IQs of the batch_id `2` students.

```sql

```

4. Find all the students who are in batches that start with the word `Jedi` (Without JOIN)

```sql

```

5. Find all the students whose IQ is greater than the average IQ of their batch.

```sql

```

6. Get all the instructors that have at least one batch (Without using joins)

```sql

```

7. Print all the names, batch ID and average IQ of the batch for each student

```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

```