1 00:00:00,330 --> 00:00:01,980 We've covered a lot in this stage. 2 00:00:01,980 --> 00:00:06,410 We've been introduced to new keywords, functions, and operators. 3 00:00:06,410 --> 00:00:08,100 Let's quickly review them and 4 00:00:08,100 --> 00:00:11,590 then you can practice them in this SQL playground associated with this video. 5 00:00:12,850 --> 00:00:14,873 Let's start with all the functions you've learned. 6 00:00:14,873 --> 00:00:18,137 [SOUND] We've used the COUNT function to count the number 7 00:00:18,137 --> 00:00:21,067 of rows depending on the queries we've created. 8 00:00:21,067 --> 00:00:24,346 Remember that when giving a specific column name, 9 00:00:24,346 --> 00:00:27,980 count won't include rows with null values. 10 00:00:27,980 --> 00:00:31,970 Use a star or asterisk to get all rows. 11 00:00:31,970 --> 00:00:36,520 The sum function is used to sum all the numeric values in a column. 12 00:00:37,530 --> 00:00:41,760 We use this to get various totals from the orders table. 13 00:00:41,760 --> 00:00:46,440 The average function is used to calculate the average values in a given column. 14 00:00:47,690 --> 00:00:52,840 The maximum and minimum functions are used to compare all values in a column and 15 00:00:52,840 --> 00:00:56,350 retrieve the minimum and maximum values. 16 00:00:56,350 --> 00:01:01,960 Finally, we use the round function to round values to a specific decimal place. 17 00:01:01,960 --> 00:01:07,170 With all of these functions, you can use all of them with all rows in the table or 18 00:01:07,170 --> 00:01:10,750 a selection of the data you define through a WHERE clause or 19 00:01:10,750 --> 00:01:13,260 group in sets of rows together. 20 00:01:13,260 --> 00:01:16,620 This takes us to the keywords you've learned. 21 00:01:16,620 --> 00:01:19,570 First, we saw the distinct keyword in action. 22 00:01:19,570 --> 00:01:22,560 This finds unique values in a column. 23 00:01:22,560 --> 00:01:25,830 Then we use the group by to perform a similar action. 24 00:01:25,830 --> 00:01:27,970 Find unique values. 25 00:01:27,970 --> 00:01:32,190 But instead of discarding duplicates, it grouped them together. 26 00:01:32,190 --> 00:01:36,080 Once the results are grouped, you can use the SQL functions to get 27 00:01:36,080 --> 00:01:38,700 information about the different groups of rows. 28 00:01:39,820 --> 00:01:44,050 Finally, if you want to filter based on aggregate information, 29 00:01:44,050 --> 00:01:45,940 you can't use a where clause. 30 00:01:45,940 --> 00:01:49,250 You have to use a having clause. 31 00:01:49,250 --> 00:01:52,690 You were introduced to some new operators by performing math 32 00:01:52,690 --> 00:01:55,350 on columns of numeric data. 33 00:01:55,350 --> 00:01:59,380 Addition, subtraction, multiplication, and division. 34 00:02:00,820 --> 00:02:05,700 Launch the SQL Playground now and you'll find another practice session for you. 35 00:02:05,700 --> 00:02:08,359 Familiarize yourself with the database schema and 36 00:02:08,359 --> 00:02:11,582 then proceed to answer questions in each of the coding areas. 37 00:02:15,579 --> 00:02:19,100 Once you're finished with this session, there's another assessment. 38 00:02:19,100 --> 00:02:22,070 This section of this course has been pretty challenging. 39 00:02:22,070 --> 00:02:23,770 And you've accomplished so much. 40 00:02:23,770 --> 00:02:24,510 You're growing. 41 00:02:24,510 --> 00:02:25,440 Keep it up. 42 00:02:25,440 --> 00:02:28,830 In the next section, we'll take a look at some more powerful functions, 43 00:02:28,830 --> 00:02:31,020 like calculating and formatting dates.