updated syntax

exercise 1.sql

@@ -1,4 +1,4 @@
 SELECT vendor_id,
-	sum(invoice_total) AS invoice_total_sum
+	SUM(invoice_total) AS invoice_total_sum
 	FROM invoices
     GROUP BY vendor_id;

exercise 2.sql

@@ -1,6 +1,6 @@
 SELECT v.vendor_name,
 		SUM(i.payment_total) AS payment_total_sum
 FROM vendors v JOIN invoices i
-WHERE v.vendor_id = i.vendor_id
+	ON v.vendor_id = i.vendor_id
 GROUP BY v.vendor_name
 ORDER BY payment_total_sum DESC;

exercise 3.sql

@@ -3,6 +3,6 @@ SELECT
     COUNT(*) AS number_of_invoices,
     SUM(i.invoice_total) AS invoice_total_sum
 FROM vendors v JOIN invoices i
-WHERE v.vendor_id = i.vendor_id
+	ON v.vendor_id = i.vendor_id
 GROUP BY v.vendor_name
 ORDER BY number_of_invoices DESC;

exercise 4.sql

@@ -3,7 +3,7 @@ SELECT DISTINCT
     COUNT(line_item_amount) AS line_item_amount_count,
     SUM(i.line_item_amount) AS line_item_amount_sum
 FROM general_ledger_accounts g JOIN invoice_line_items i
-WHERE g.account_number = i.account_number
+	ON g.account_number = i.account_number
 GROUP BY g.account_description
 HAVING line_item_amount_count > 1
 ORDER BY line_item_amount_sum DESC;

exercise 5.sql

@@ -4,7 +4,7 @@ SELECT DISTINCT
     SUM(i.line_item_amount) AS line_item_amount_sum,
     n.invoice_date
 FROM general_ledger_accounts g JOIN invoice_line_items i JOIN invoices n
-WHERE g.account_number = i.account_number AND i.invoice_id = n.invoice_id
+	ON g.account_number = i.account_number AND i.invoice_id = n.invoice_id
 GROUP BY g.account_description
 HAVING n.invoice_date >= '2018-04-01' AND n.invoice_date <= '2018-06-30'
 ORDER BY line_item_amount_sum DESC;

exercise 6.sql

@@ -2,5 +2,5 @@ SELECT
 	i.account_number,
     SUM(i.line_item_amount) AS line_items_amount_sum
 FROM invoice_line_items i JOIN general_ledger_accounts g
-WHERE i.account_number = g.account_number
+	ON i.account_number = g.account_number
 GROUP BY i.account_number WITH ROLLUP;

exercise 7.sql

@@ -2,6 +2,6 @@ SELECT
 	v.vendor_name,
     COUNT(DISTINCT g.account_number) AS distinct_accounts
 FROM vendors v JOIN general_ledger_accounts g JOIN invoice_line_items i JOIN invoices n
-WHERE v.vendor_id = n.vendor_id AND i.invoice_id = n.invoice_id AND i.account_number = g.account_number
+	ON v.vendor_id = n.vendor_id AND i.invoice_id = n.invoice_id AND i.account_number = g.account_number
 GROUP BY v.vendor_name
 HAVING distinct_accounts > 1;