WEBVTT 00:00:00.350 --> 00:00:01.491 Welcome back! 00:00:01.671 --> 00:00:04.372 We can already read fields through relationships. 00:00:04.552 --> 00:00:08.147 Now let us use those same paths to choose and sort records. 00:00:09.477 --> 00:00:11.357 Continue in the same console. 00:00:11.537 --> 00:00:15.355 We will use the customers and invoices we imported last time. 00:00:15.535 --> 00:00:20.967 If Python was closed, the download includes a script to rebuild that temporary dataset. 00:00:22.350 --> 00:00:24.421 Let's find invoices for Florence. 00:00:24.601 --> 00:00:26.503 Use the customer city in where. 00:00:26.683 --> 00:00:30.460 Colon city is a parameter: its value is passed separately. 00:00:30.640 --> 00:00:32.959 We only ask to return the invoice number. 00:00:34.350 --> 00:00:36.252 Let's sort invoices by city. 00:00:36.432 --> 00:00:38.505 Use the same path in order by. 00:00:38.685 --> 00:00:41.299 Without a direction, the order is ascending. 00:00:41.479 --> 00:00:43.785 Limit keeps the displayed result short. 00:00:45.183 --> 00:00:47.033 Let's show the newest rows first. 00:00:47.213 --> 00:00:50.231 From an invoice row, follow its invoice to the date. 00:00:50.411 --> 00:00:52.262 Add DESC for descending order. 00:00:52.442 --> 00:00:55.247 These three rows belong to the latest invoice. 00:00:56.600 --> 00:00:58.428 Now start from an invoice row. 00:00:58.608 --> 00:01:02.607 To reach the customer city, go through the invoice and then the customer. 00:01:03.937 --> 00:01:05.763 Let's find rows for Florence. 00:01:05.943 --> 00:01:08.197 The filter follows two relationships. 00:01:08.377 --> 00:01:11.823 The returned columns follow the product relation instead. 00:01:12.003 --> 00:01:15.107 A field used in a filter need not be selected. 00:01:16.517 --> 00:01:18.311 Let's combine the conditions. 00:01:18.491 --> 00:01:22.468 Keep Florence rows from October first, newest invoices first. 00:01:22.648 --> 00:01:24.557 City and date are parameters. 00:01:24.737 --> 00:01:27.661 Neither filtered field needs to appear in the result. 00:01:27.841 --> 00:01:31.041 The same paths work in columns, where, and order by. 00:01:32.371 --> 00:01:34.369 Let's close this read transaction. 00:01:34.549 --> 00:01:38.249 We only read the data; the imported records have not changed. 00:01:39.617 --> 00:01:41.263 Thanks for following along! 00:01:41.443 --> 00:01:44.962 Use relationship fields wherever the query needs them. 00:01:45.142 --> 00:01:50.146 Select only what you want to read, and add just the conditions and ordering you need.