fix(sql/catalog): Support pg_dump output

internal/endtoend/testdata/pg_dump/query.sql

@@ -0,0 +1,19 @@
+-- name: GetAuthor :one
+SELECT * FROM authors
+WHERE id = $1 LIMIT 1;
+
+-- name: ListAuthors :many
+SELECT * FROM authors
+ORDER BY name;
+
+-- name: CreateAuthor :one
+INSERT INTO authors (
+          name, bio
+) VALUES (
+  $1, $2
+)
+RETURNING *;
+
+-- name: DeleteAuthor :exec
+DELETE FROM authors
+WHERE id = $1;

internal/endtoend/testdata/pg_dump/schema.sql

@@ -0,0 +1,89 @@
+--
+-- PostgreSQL database dump
+--
+
+-- Dumped from database version 15.3 (Debian 15.3-1.pgdg120+1)
+-- Dumped by pg_dump version 15.3
+
+SET statement_timeout = 0;
+SET lock_timeout = 0;
+SET idle_in_transaction_session_timeout = 0;
+SET client_encoding = 'UTF8';
+SET standard_conforming_strings = on;
+SELECT pg_catalog.set_config('search_path', '', false);
+SET check_function_bodies = false;
+SET xmloption = content;
+SET client_min_messages = warning;
+SET row_security = off;
+
+--
+-- Name: public; Type: SCHEMA; Schema: -; Owner: pg_database_owner
+--
+
+CREATE SCHEMA public;
+
+
+ALTER SCHEMA public OWNER TO pg_database_owner;
+
+--
+-- Name: SCHEMA public; Type: COMMENT; Schema: -; Owner: pg_database_owner
+--
+
+COMMENT ON SCHEMA public IS 'standard public schema';
+
+
+SET default_table_access_method = heap;
+
+--
+-- Name: authors; Type: TABLE; Schema: public; Owner: postgres
+--
+
+CREATE TABLE public.authors (
+    id bigint NOT NULL,
+    name text NOT NULL,
+    bio text
+);
+
+
+ALTER TABLE public.authors OWNER TO postgres;
+
+--
+-- Name: authors_id_seq; Type: SEQUENCE; Schema: public; Owner: postgres
+--
+
+CREATE SEQUENCE public.authors_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+ALTER TABLE public.authors_id_seq OWNER TO postgres;
+
+--
+-- Name: authors_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: postgres
+--
+
+ALTER SEQUENCE public.authors_id_seq OWNED BY public.authors.id;
+
+
+--
+-- Name: authors id; Type: DEFAULT; Schema: public; Owner: postgres
+--
+
+ALTER TABLE ONLY public.authors ALTER COLUMN id SET DEFAULT nextval('public.authors_id_seq'::regclass);
+
+
+--
+-- Name: authors authors_pkey; Type: CONSTRAINT; Schema: public; Owner: postgres
+--
+
+ALTER TABLE ONLY public.authors
+    ADD CONSTRAINT authors_pkey PRIMARY KEY (id);
+
+
+--
+-- PostgreSQL database dump complete
+--
+

internal/endtoend/testdata/pg_dump/sqlc.json

@@ -0,0 +1,12 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "path": "db",
+      "engine": "postgresql",
+      "schema": "schema.sql",
+      "queries": "query.sql"
+    }
+  ]
+}
+

internal/sql/catalog/schema.go

@@ -100,6 +100,11 @@ func (c *Catalog) createSchema(stmt *ast.CreateSchemaStmt) error {
 		return fmt.Errorf("create schema: empty name")
 	}
 	if _, err := c.getSchema(*stmt.Name); err == nil {
+		// If the default schema already exists, treat additional CREATE SCHEMA
+		// statements as no-ops.
+		if *stmt.Name == c.DefaultSchema {
+			return nil
+		}
 		if !stmt.IfNotExists {
 			return sqlerr.SchemaExists(*stmt.Name)
 		}