ExampleDoUpdate does't work in postgres

[asv]

Describe the bug

goqu/expressions_example_test.go

Line 521 in ce5475c

func ExampleDoUpdate() {

In the generated SQL, the EXCLUDED keyword is escaped according to goqu.I rules, however the resulting SQL is not valid for postgres.

INSERT INTO "items" ("address") VALUES ('111 Address') ON CONFLICT (address) DO UPDATE SET "address"="EXCLUDED"."address";
ERROR:  missing FROM-clause entry for table "EXCLUDED"
LINE 1: ...s') ON CONFLICT (address) DO UPDATE SET "address"="EXCLUDED"...

To Reproduce

Try to execute the generated code in Postgres.

Expected behavior

Statement must be successfully executed.

Dialect:

• postgres

[doug-martin]

@asv good catch I took the example from https://www.postgresql.org/docs/9.5/sql-insert.html.

From the postgres docs.

Insert or update new distributors as appropriate. Assumes a unique index has been defined that constrains values appearing in the did column. Note that the special excluded table is used to reference values originally proposed for insertion:

INSERT INTO distributors (did, dname)
    VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
    ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;

But it appears that wont actually work.