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

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+# 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
+
+```
+