Add support for WITH statements and Common Table Expressions.

tests/mysql/with_test.go

@@ -0,0 +1,61 @@
+package mysql
+
+import (
+	"github.com/go-jet/jet/internal/testutils"
+	. "github.com/go-jet/jet/mysql"
+	. "github.com/go-jet/jet/tests/.gentestdata/mysql/dvds/table"
+	"github.com/stretchr/testify/require"
+	"strings"
+	"testing"
+)
+
+func TestWITH_SELECT(t *testing.T) {
+	salesRep := CTE("sales_rep")
+	salesRepStaffID := Staff.StaffID.From(salesRep)
+	salesRepFullName := StringColumn("sales_rep_full_name").From(salesRep)
+	customerSalesRep := CTE("customer_sales_rep")
+
+	stmt := WITH(
+		salesRep.AS(
+			SELECT(
+				Staff.StaffID,
+				Staff.FirstName.CONCAT(Staff.LastName).AS(salesRepFullName.Name()),
+			).FROM(Staff),
+		),
+		customerSalesRep.AS(
+			SELECT(
+				Customer.FirstName.CONCAT(Customer.LastName).AS("customer_name"),
+				salesRepFullName,
+			).FROM(
+				salesRep.
+					INNER_JOIN(Store, Store.ManagerStaffID.EQ(salesRepStaffID)).
+					INNER_JOIN(Customer, Customer.StoreID.EQ(Store.StoreID)),
+			),
+		),
+	)(
+		SELECT(customerSalesRep.AllColumns()).
+			FROM(customerSalesRep),
+	)
+
+	//fmt.Println(stmt.DebugSql())
+
+	testutils.AssertStatementSql(t, stmt, strings.Replace(`
+WITH sales_rep AS (
+     SELECT staff.staff_id AS "staff.staff_id",
+          (CONCAT(staff.first_name, staff.last_name)) AS "sales_rep_full_name"
+     FROM dvds.staff
+),customer_sales_rep AS (
+     SELECT (CONCAT(customer.first_name, customer.last_name)) AS "customer_name",
+          sales_rep.sales_rep_full_name AS "sales_rep_full_name"
+     FROM sales_rep
+          INNER JOIN dvds.store ON (store.manager_staff_id = sales_rep.''staff.staff_id'')
+          INNER JOIN dvds.customer ON (customer.store_id = store.store_id)
+)
+SELECT customer_sales_rep.customer_name AS "customer_name",
+     customer_sales_rep.sales_rep_full_name AS "sales_rep_full_name"
+FROM customer_sales_rep;
+`, "''", "`", -1))
+
+	_, err := stmt.Exec(db)
+	require.NoError(t, err)
+}