Repro for #15342: The order of join-type causes query fail (#17201)

frontend/test/metabase-db/mysql/reproductions/15342.cy.spec.js

+import { restore, popover, addMySQLDatabase } from "__support__/e2e/cypress";
+
+const MYSQL_DB_NAME = "QA MySQL8";
+
+describe.skip("15342", () => {
+  beforeEach(() => {
+    restore();
+    cy.signInAsAdmin();
+    cy.viewport(4000, 1200); // huge width required so three joined tables can fit
+    addMySQLDatabase(MYSQL_DB_NAME);
+  });
+
+  it("should correctly order joins for MySQL queries", () => {
+    cy.intercept("POST", "/api/dataset").as("query");
+
+    cy.visit("/question/new");
+    cy.findByText("Custom question").click();
+    cy.findByText(MYSQL_DB_NAME).click();
+    cy.findByText("People").click();
+
+    addJoin({
+      leftColumn: "ID",
+      rightTable: "Orders",
+      rightColumn: "Product ID",
+    });
+
+    addJoin({
+      leftTable: "Orders",
+      leftColumn: "Product ID",
+      rightTable: "Products",
+      rightColumn: "ID",
+      joinType: "inner",
+    });
+
+    cy.button("Visualize").click();
+    cy.wait("@query");
+    cy.get(".Visualization").within(() => {
+      cy.findByText("Email"); // from People table
+      cy.findByText("Orders → ID"); // joined Orders table columns
+      cy.findByText("Products → ID"); // joined Products table columns
+    });
+  });
+});
+
+function selectFromDropdown(itemName) {
+  return popover().findByText(itemName);
+}
+
+const JOIN_LABEL = {
+  left: "Left outer join",
+  right: "Right outer join",
+  inner: "Inner join",
+};
+
+function addJoin({
+  leftTable,
+  leftColumn,
+  rightTable,
+  rightColumn,
+  joinType = "left",
+} = {}) {
+  cy.icon("join_left_outer")
+    .last()
+    .click();
+
+  selectFromDropdown(rightTable).click();
+
+  if (leftTable) {
+    selectFromDropdown(leftTable).click();
+  }
+
+  selectFromDropdown(leftColumn).click();
+  selectFromDropdown(rightColumn).click();
+
+  cy.findAllByText("Join data")
+    .last()
+    .next()
+    .within(() => {
+      cy.icon("join_left_outer").click();
+    });
+  selectFromDropdown(JOIN_LABEL[joinType]).click();
+}