fix: pgx closed batch return pointer if need #1959 (#1960)

Author: flymedllva

internal/codegen/golang/templates/pgx/batchCode.tmpl

@@ -107,7 +107,7 @@ func (b *{{.MethodName}}BatchResults) QueryRow(f func(int, {{.Ret.DefineType}},
      var {{.Ret.Name}} {{.Ret.Type}}
      if b.closed {
         if f != nil {
-          f(t, {{.Ret.Name}}, errors.New("batch already closed"))
+          f(t, {{if .Ret.IsPointer}}nil{{else}}{{.Ret.Name}}{{end}}, errors.New("batch already closed"))
         }
         continue
      }

internal/endtoend/testdata/emit_result_and_params_struct_pointers/go/db.go renamed to internal/endtoend/testdata/emit_result_and_params_struct_pointers/mysql/go/db.go

@@ -0,0 +1,16 @@
+CREATE TABLE foo (a integer, b integer);
+
+-- name: InsertValues :batchone
+INSERT INTO foo (a, b)
+VALUES ($1, $2)
+ON CONFLICT DO NOTHING
+RETURNING *;
+
+-- name: GetOne :one
+SELECT * FROM foo WHERE a = ? AND b = ? LIMIT 1;
+
+-- name: GetAll :many
+SELECT * FROM foo;
+
+-- name: GetAllAByB :many
+SELECT a FROM foo WHERE b = ?;

internal/endtoend/testdata/emit_result_and_params_struct_pointers/go/models.go renamed to internal/endtoend/testdata/emit_result_and_params_struct_pointers/mysql/go/models.go

@@ -0,0 +1,19 @@
+{
+  "version": "2",
+  "sql": [
+    {
+      "engine": "postgresql",
+      "schema": "query.sql",
+      "queries": "query.sql",
+      "gen": {
+        "go": {
+          "package": "querytest",
+          "sql_package": "pgx/v4",
+          "out": "go",
+          "emit_result_struct_pointers": true,
+          "emit_params_struct_pointers": true
+        }
+      }
+    }
+  ]
+}