From f834122366e8980380c47f74804b6bc6bf9aa846 Mon Sep 17 00:00:00 2001
From: Daniel Simmons <dan@dans.im>
Date: Sun, 30 Jan 2022 22:54:19 +0100
Subject: [PATCH] Fix return type for subqueries in MySQL (#1383)

---
 internal/compiler/output_columns.go           | 11 ++++
 .../select_nested_count/mysql/go/db.go        | 29 +++++++++++
 .../select_nested_count/mysql/go/models.go    | 19 +++++++
 .../select_nested_count/mysql/go/query.sql.go | 52 +++++++++++++++++++
 .../select_nested_count/mysql/query.sql       | 19 +++++++
 .../select_nested_count/mysql/sqlc.json       | 12 +++++
 6 files changed, 142 insertions(+)
 create mode 100644 internal/endtoend/testdata/select_nested_count/mysql/go/db.go
 create mode 100644 internal/endtoend/testdata/select_nested_count/mysql/go/models.go
 create mode 100644 internal/endtoend/testdata/select_nested_count/mysql/go/query.sql.go
 create mode 100644 internal/endtoend/testdata/select_nested_count/mysql/query.sql
 create mode 100644 internal/endtoend/testdata/select_nested_count/mysql/sqlc.json

diff --git a/internal/compiler/output_columns.go b/internal/compiler/output_columns.go
index 0b0e770025..e66cb7a006 100644
--- a/internal/compiler/output_columns.go
+++ b/internal/compiler/output_columns.go
@@ -268,6 +268,17 @@ func outputColumns(qc *QueryCatalog, node ast.Node) ([]*Column, error) {
 			}
 			cols = append(cols, col)
 
+		case *ast.SelectStmt:
+			subcols, err := outputColumns(qc, n)
+			if err != nil {
+				return nil, err
+			}
+			first := subcols[0]
+			if res.Name != nil {
+				first.Name = *res.Name
+			}
+			cols = append(cols, first)
+
 		default:
 			name := ""
 			if res.Name != nil {
diff --git a/internal/endtoend/testdata/select_nested_count/mysql/go/db.go b/internal/endtoend/testdata/select_nested_count/mysql/go/db.go
new file mode 100644
index 0000000000..6a99519302
--- /dev/null
+++ b/internal/endtoend/testdata/select_nested_count/mysql/go/db.go
@@ -0,0 +1,29 @@
+// Code generated by sqlc. DO NOT EDIT.
+
+package querytest
+
+import (
+	"context"
+	"database/sql"
+)
+
+type DBTX interface {
+	ExecContext(context.Context, string, ...interface{}) (sql.Result, error)
+	PrepareContext(context.Context, string) (*sql.Stmt, error)
+	QueryContext(context.Context, string, ...interface{}) (*sql.Rows, error)
+	QueryRowContext(context.Context, string, ...interface{}) *sql.Row
+}
+
+func New(db DBTX) *Queries {
+	return &Queries{db: db}
+}
+
+type Queries struct {
+	db DBTX
+}
+
+func (q *Queries) WithTx(tx *sql.Tx) *Queries {
+	return &Queries{
+		db: tx,
+	}
+}
diff --git a/internal/endtoend/testdata/select_nested_count/mysql/go/models.go b/internal/endtoend/testdata/select_nested_count/mysql/go/models.go
new file mode 100644
index 0000000000..c1f8631d13
--- /dev/null
+++ b/internal/endtoend/testdata/select_nested_count/mysql/go/models.go
@@ -0,0 +1,19 @@
+// Code generated by sqlc. DO NOT EDIT.
+
+package querytest
+
+import (
+	"database/sql"
+)
+
+type Author struct {
+	ID   int64
+	Name string
+	Bio  sql.NullString
+}
+
+type Book struct {
+	ID       int64
+	AuthorID int64
+	Title    string
+}
diff --git a/internal/endtoend/testdata/select_nested_count/mysql/go/query.sql.go b/internal/endtoend/testdata/select_nested_count/mysql/go/query.sql.go
new file mode 100644
index 0000000000..4159cdd5ba
--- /dev/null
+++ b/internal/endtoend/testdata/select_nested_count/mysql/go/query.sql.go
@@ -0,0 +1,52 @@
+// Code generated by sqlc. DO NOT EDIT.
+// source: query.sql
+
+package querytest
+
+import (
+	"context"
+	"database/sql"
+)
+
+const getAuthorsWithBooksCount = `-- name: GetAuthorsWithBooksCount :many
+SELECT id, name, bio, (
+  SELECT COUNT(id) FROM books
+  WHERE books.author_id = id
+) AS books_count
+FROM authors
+`
+
+type GetAuthorsWithBooksCountRow struct {
+	ID         int64
+	Name       string
+	Bio        sql.NullString
+	BooksCount int64
+}
+
+func (q *Queries) GetAuthorsWithBooksCount(ctx context.Context) ([]GetAuthorsWithBooksCountRow, error) {
+	rows, err := q.db.QueryContext(ctx, getAuthorsWithBooksCount)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []GetAuthorsWithBooksCountRow
+	for rows.Next() {
+		var i GetAuthorsWithBooksCountRow
+		if err := rows.Scan(
+			&i.ID,
+			&i.Name,
+			&i.Bio,
+			&i.BooksCount,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
diff --git a/internal/endtoend/testdata/select_nested_count/mysql/query.sql b/internal/endtoend/testdata/select_nested_count/mysql/query.sql
new file mode 100644
index 0000000000..fb9d37dfa1
--- /dev/null
+++ b/internal/endtoend/testdata/select_nested_count/mysql/query.sql
@@ -0,0 +1,19 @@
+CREATE TABLE authors (
+  id   bigint    PRIMARY KEY,
+  name text      NOT NULL,
+  bio  text
+);
+
+CREATE TABLE books (
+  id bigint PRIMARY KEY,
+  author_id bigint NOT NULL
+    REFERENCES authors(id),
+  title text NOT NULL
+);
+
+-- name: GetAuthorsWithBooksCount :many
+SELECT *, (
+  SELECT COUNT(id) FROM books
+  WHERE books.author_id = id
+) AS books_count
+FROM authors;
diff --git a/internal/endtoend/testdata/select_nested_count/mysql/sqlc.json b/internal/endtoend/testdata/select_nested_count/mysql/sqlc.json
new file mode 100644
index 0000000000..cb8f8d5ee6
--- /dev/null
+++ b/internal/endtoend/testdata/select_nested_count/mysql/sqlc.json
@@ -0,0 +1,12 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "path": "go",
+      "name": "querytest",
+      "schema": "query.sql",
+      "queries": "query.sql",
+      "engine": "mysql"
+    }
+  ]
+}