diff --git a/examples/ondeck/mysql/city.sql.go b/examples/ondeck/mysql/city.sql.go
new file mode 100644
index 0000000000..f6ae1ea873
--- /dev/null
+++ b/examples/ondeck/mysql/city.sql.go
@@ -0,0 +1,86 @@
+// Code generated by sqlc. DO NOT EDIT.
+// source: city.sql
+
+package ondeck
+
+import (
+	"context"
+	"database/sql"
+)
+
+const createCity = `-- name: CreateCity :execresult
+INSERT INTO city (
+    name,
+    slug
+) VALUES (
+    ?,
+    ? 
+)
+`
+
+type CreateCityParams struct {
+	Name string `json:"name"`
+	Slug string `json:"slug"`
+}
+
+func (q *Queries) CreateCity(ctx context.Context, arg CreateCityParams) (sql.Result, error) {
+	return q.exec(ctx, q.createCityStmt, createCity, arg.Name, arg.Slug)
+}
+
+const getCity = `-- name: GetCity :one
+SELECT slug, name
+FROM city
+WHERE slug = ?
+`
+
+func (q *Queries) GetCity(ctx context.Context, slug string) (City, error) {
+	row := q.queryRow(ctx, q.getCityStmt, getCity, slug)
+	var i City
+	err := row.Scan(&i.Slug, &i.Name)
+	return i, err
+}
+
+const listCities = `-- name: ListCities :many
+SELECT slug, name
+FROM city
+ORDER BY name
+`
+
+func (q *Queries) ListCities(ctx context.Context) ([]City, error) {
+	rows, err := q.query(ctx, q.listCitiesStmt, listCities)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []City
+	for rows.Next() {
+		var i City
+		if err := rows.Scan(&i.Slug, &i.Name); 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
+}
+
+const updateCityName = `-- name: UpdateCityName :exec
+UPDATE city
+SET name = ?
+WHERE slug = ?
+`
+
+type UpdateCityNameParams struct {
+	Name string `json:"name"`
+	Slug string `json:"slug"`
+}
+
+func (q *Queries) UpdateCityName(ctx context.Context, arg UpdateCityNameParams) error {
+	_, err := q.exec(ctx, q.updateCityNameStmt, updateCityName, arg.Name, arg.Slug)
+	return err
+}
diff --git a/examples/ondeck/db.go b/examples/ondeck/mysql/db.go
similarity index 100%
rename from examples/ondeck/db.go
rename to examples/ondeck/mysql/db.go
diff --git a/examples/ondeck/mysql/db_test.go b/examples/ondeck/mysql/db_test.go
new file mode 100644
index 0000000000..9d189f9477
--- /dev/null
+++ b/examples/ondeck/mysql/db_test.go
@@ -0,0 +1,163 @@
+// +build examples
+
+package ondeck
+
+import (
+	"context"
+	"database/sql"
+	"strings"
+	"testing"
+
+	"github.com/kyleconroy/sqlc/internal/sqltest"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func join(vals ...string) sql.NullString {
+	if len(vals) == 0 {
+		return sql.NullString{}
+	}
+	return sql.NullString{
+		Valid:  true,
+		String: strings.Join(vals, ","),
+	}
+}
+
+func runOnDeckQueries(t *testing.T, q *Queries) {
+	ctx := context.Background()
+
+	_, err := q.CreateCity(ctx, CreateCityParams{
+		Slug: "san-francisco",
+		Name: "San Francisco",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	city, err := q.GetCity(ctx, "san-francisco")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	venueResult, err := q.CreateVenue(ctx, CreateVenueParams{
+		Slug:            "the-fillmore",
+		Name:            "The Fillmore",
+		City:            city.Slug,
+		SpotifyPlaylist: "spotify:uri",
+		Status:          StatusOpen,
+		Statuses:        join(string(StatusOpen), string(StatusClosed)),
+		Tags:            join("rock", "punk"),
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	venueID, err := venueResult.LastInsertId()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	venue, err := q.GetVenue(ctx, GetVenueParams{
+		Slug: "the-fillmore",
+		City: city.Slug,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if diff := cmp.Diff(venue.ID, venueID); diff != "" {
+		t.Errorf("venue ID mismatch:\n%s", diff)
+	}
+
+	{
+		actual, err := q.VenueCountByCity(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		if diff := cmp.Diff(actual, []VenueCountByCityRow{
+			{city.Slug, int64(1)},
+		}); diff != "" {
+			t.Errorf("venue count mismatch:\n%s", diff)
+		}
+	}
+
+	{
+		actual, err := q.ListCities(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		if diff := cmp.Diff(actual, []City{city}); diff != "" {
+			t.Errorf("list city mismatch:\n%s", diff)
+		}
+	}
+
+	{
+		actual, err := q.ListVenues(ctx, city.Slug)
+		if err != nil {
+			t.Error(err)
+		}
+		if diff := cmp.Diff(actual, []Venue{venue}); diff != "" {
+			t.Errorf("list venue mismatch:\n%s", diff)
+		}
+	}
+
+	{
+		err := q.UpdateCityName(ctx, UpdateCityNameParams{
+			Slug: city.Slug,
+			Name: "SF",
+		})
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	{
+		expected := "Fillmore"
+		err := q.UpdateVenueName(ctx, UpdateVenueNameParams{
+			Slug: venue.Slug,
+			Name: expected,
+		})
+		if err != nil {
+			t.Error(err)
+		}
+		fresh, err := q.GetVenue(ctx, GetVenueParams{
+			Slug: venue.Slug,
+			City: city.Slug,
+		})
+		if diff := cmp.Diff(expected, fresh.Name); diff != "" {
+			t.Errorf("update venue mismatch:\n%s", diff)
+		}
+	}
+
+	{
+		err := q.DeleteVenue(ctx, DeleteVenueParams{
+			Slug:   venue.Slug,
+			Slug_2: venue.Slug,
+		})
+		if err != nil {
+			t.Error(err)
+		}
+	}
+}
+
+func TestPrepared(t *testing.T) {
+	t.Parallel()
+
+	sdb, cleanup := sqltest.MySQL(t, []string{"schema"})
+	defer cleanup()
+
+	q, err := Prepare(context.Background(), sdb)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	runOnDeckQueries(t, q)
+}
+
+func TestQueries(t *testing.T) {
+	t.Parallel()
+
+	sdb, cleanup := sqltest.MySQL(t, []string{"schema"})
+	defer cleanup()
+
+	runOnDeckQueries(t, New(sdb))
+}
diff --git a/examples/ondeck/mysql/models.go b/examples/ondeck/mysql/models.go
new file mode 100644
index 0000000000..3d74b01cc3
--- /dev/null
+++ b/examples/ondeck/mysql/models.go
@@ -0,0 +1,49 @@
+// Code generated by sqlc. DO NOT EDIT.
+
+package ondeck
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+)
+
+type Status string
+
+const (
+	StatusOpen   Status = "open"
+	StatusClosed Status = "closed"
+)
+
+func (e *Status) Scan(src interface{}) error {
+	switch s := src.(type) {
+	case []byte:
+		*e = Status(s)
+	case string:
+		*e = Status(s)
+	default:
+		return fmt.Errorf("unsupported scan type for Status: %T", src)
+	}
+	return nil
+}
+
+type City struct {
+	Slug string `json:"slug"`
+	Name string `json:"name"`
+}
+
+// Venues are places where muisc happens
+type Venue struct {
+	ID int64 `json:"id"`
+	// Venues can be either open or closed
+	Status   Status         `json:"status"`
+	Statuses sql.NullString `json:"statuses"`
+	// This value appears in public URLs
+	Slug            string         `json:"slug"`
+	Name            string         `json:"name"`
+	City            string         `json:"city"`
+	SpotifyPlaylist string         `json:"spotify_playlist"`
+	SongkickID      sql.NullString `json:"songkick_id"`
+	Tags            sql.NullString `json:"tags"`
+	CreatedAt       time.Time      `json:"created_at"`
+}
diff --git a/examples/ondeck/mysql/querier.go b/examples/ondeck/mysql/querier.go
new file mode 100644
index 0000000000..60e8f0daa0
--- /dev/null
+++ b/examples/ondeck/mysql/querier.go
@@ -0,0 +1,23 @@
+// Code generated by sqlc. DO NOT EDIT.
+
+package ondeck
+
+import (
+	"context"
+	"database/sql"
+)
+
+type Querier interface {
+	CreateCity(ctx context.Context, arg CreateCityParams) (sql.Result, error)
+	CreateVenue(ctx context.Context, arg CreateVenueParams) (sql.Result, error)
+	DeleteVenue(ctx context.Context, arg DeleteVenueParams) error
+	GetCity(ctx context.Context, slug string) (City, error)
+	GetVenue(ctx context.Context, arg GetVenueParams) (Venue, error)
+	ListCities(ctx context.Context) ([]City, error)
+	ListVenues(ctx context.Context, city string) ([]Venue, error)
+	UpdateCityName(ctx context.Context, arg UpdateCityNameParams) error
+	UpdateVenueName(ctx context.Context, arg UpdateVenueNameParams) error
+	VenueCountByCity(ctx context.Context) ([]VenueCountByCityRow, error)
+}
+
+var _ Querier = (*Queries)(nil)
diff --git a/examples/ondeck/mysql/query/city.sql b/examples/ondeck/mysql/query/city.sql
new file mode 100644
index 0000000000..275f4f2e68
--- /dev/null
+++ b/examples/ondeck/mysql/query/city.sql
@@ -0,0 +1,23 @@
+/* name: ListCities :many */
+SELECT *
+FROM city
+ORDER BY name;
+
+/* name: GetCity :one */
+SELECT *
+FROM city
+WHERE slug = ?;
+
+/* name: CreateCity :execresult */
+INSERT INTO city (
+    name,
+    slug
+) VALUES (
+    ?,
+    ? 
+); 
+
+/* name: UpdateCityName :exec */
+UPDATE city
+SET name = ?
+WHERE slug = ?;
diff --git a/examples/ondeck/mysql/query/venue.sql b/examples/ondeck/mysql/query/venue.sql
new file mode 100644
index 0000000000..a1dd7a1633
--- /dev/null
+++ b/examples/ondeck/mysql/query/venue.sql
@@ -0,0 +1,48 @@
+/* name: ListVenues :many */
+SELECT *
+FROM venue
+WHERE city = ?
+ORDER BY name;
+
+/* name: DeleteVenue :exec */
+DELETE FROM venue
+WHERE slug = ? AND slug = ?;
+
+/* name: GetVenue :one */
+SELECT *
+FROM venue
+WHERE slug = ? AND city = ?;
+
+/* name: CreateVenue :execresult */
+INSERT INTO venue (
+    slug,
+    name,
+    city,
+    created_at,
+    spotify_playlist,
+    status,
+    statuses,
+    tags
+) VALUES (
+    ?,
+    ?,
+    ?,
+    NOW(),
+    ?,
+    ?,
+    ?,
+    ?
+);
+
+/* name: UpdateVenueName :exec */
+UPDATE venue
+SET name = ?
+WHERE slug = ?;
+
+/* name: VenueCountByCity :many */
+SELECT
+    city,
+    count(*)
+FROM venue
+GROUP BY 1
+ORDER BY 1;
diff --git a/examples/ondeck/mysql/schema/0001_city.sql b/examples/ondeck/mysql/schema/0001_city.sql
new file mode 100644
index 0000000000..6be35d16bf
--- /dev/null
+++ b/examples/ondeck/mysql/schema/0001_city.sql
@@ -0,0 +1,4 @@
+CREATE TABLE city (
+    slug varchar(255) PRIMARY KEY,
+    name text NOT NULL
+)
diff --git a/examples/ondeck/mysql/schema/0002_venue.sql b/examples/ondeck/mysql/schema/0002_venue.sql
new file mode 100644
index 0000000000..4fc842cee0
--- /dev/null
+++ b/examples/ondeck/mysql/schema/0002_venue.sql
@@ -0,0 +1,12 @@
+CREATE TABLE venues (
+    id               SERIAL primary key,
+    dropped          text,
+    status           ENUM('open', 'closed') not null COMMENT 'Venues can be either open or closed',
+    statuses         text, -- status[],
+    slug             text         not null COMMENT 'This value appears in public URLs',
+    name             varchar(255) not null,
+    city             text         not null references city(slug),
+    spotify_playlist varchar(255) not null,
+    songkick_id      text,
+    tags             text  -- text[]
+) COMMENT='Venues are places where muisc happens';
diff --git a/examples/ondeck/schema/0003_add_column.sql b/examples/ondeck/mysql/schema/0003_add_column.sql
similarity index 100%
rename from examples/ondeck/schema/0003_add_column.sql
rename to examples/ondeck/mysql/schema/0003_add_column.sql
diff --git a/examples/ondeck/mysql/venue.sql.go b/examples/ondeck/mysql/venue.sql.go
new file mode 100644
index 0000000000..30749fabf5
--- /dev/null
+++ b/examples/ondeck/mysql/venue.sql.go
@@ -0,0 +1,191 @@
+// Code generated by sqlc. DO NOT EDIT.
+// source: venue.sql
+
+package ondeck
+
+import (
+	"context"
+	"database/sql"
+)
+
+const createVenue = `-- name: CreateVenue :execresult
+INSERT INTO venue (
+    slug,
+    name,
+    city,
+    created_at,
+    spotify_playlist,
+    status,
+    statuses,
+    tags
+) VALUES (
+    ?,
+    ?,
+    ?,
+    NOW(),
+    ?,
+    ?,
+    ?,
+    ?
+)
+`
+
+type CreateVenueParams struct {
+	Slug            string         `json:"slug"`
+	Name            string         `json:"name"`
+	City            string         `json:"city"`
+	SpotifyPlaylist string         `json:"spotify_playlist"`
+	Status          Status         `json:"status"`
+	Statuses        sql.NullString `json:"statuses"`
+	Tags            sql.NullString `json:"tags"`
+}
+
+func (q *Queries) CreateVenue(ctx context.Context, arg CreateVenueParams) (sql.Result, error) {
+	return q.exec(ctx, q.createVenueStmt, createVenue,
+		arg.Slug,
+		arg.Name,
+		arg.City,
+		arg.SpotifyPlaylist,
+		arg.Status,
+		arg.Statuses,
+		arg.Tags,
+	)
+}
+
+const deleteVenue = `-- name: DeleteVenue :exec
+DELETE FROM venue
+WHERE slug = ? AND slug = ?
+`
+
+type DeleteVenueParams struct {
+	Slug   string `json:"slug"`
+	Slug_2 string `json:"slug_2"`
+}
+
+func (q *Queries) DeleteVenue(ctx context.Context, arg DeleteVenueParams) error {
+	_, err := q.exec(ctx, q.deleteVenueStmt, deleteVenue, arg.Slug, arg.Slug_2)
+	return err
+}
+
+const getVenue = `-- name: GetVenue :one
+SELECT id, status, statuses, slug, name, city, spotify_playlist, songkick_id, tags, created_at
+FROM venue
+WHERE slug = ? AND city = ?
+`
+
+type GetVenueParams struct {
+	Slug string `json:"slug"`
+	City string `json:"city"`
+}
+
+func (q *Queries) GetVenue(ctx context.Context, arg GetVenueParams) (Venue, error) {
+	row := q.queryRow(ctx, q.getVenueStmt, getVenue, arg.Slug, arg.City)
+	var i Venue
+	err := row.Scan(
+		&i.ID,
+		&i.Status,
+		&i.Statuses,
+		&i.Slug,
+		&i.Name,
+		&i.City,
+		&i.SpotifyPlaylist,
+		&i.SongkickID,
+		&i.Tags,
+		&i.CreatedAt,
+	)
+	return i, err
+}
+
+const listVenues = `-- name: ListVenues :many
+SELECT id, status, statuses, slug, name, city, spotify_playlist, songkick_id, tags, created_at
+FROM venue
+WHERE city = ?
+ORDER BY name
+`
+
+func (q *Queries) ListVenues(ctx context.Context, city string) ([]Venue, error) {
+	rows, err := q.query(ctx, q.listVenuesStmt, listVenues, city)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []Venue
+	for rows.Next() {
+		var i Venue
+		if err := rows.Scan(
+			&i.ID,
+			&i.Status,
+			&i.Statuses,
+			&i.Slug,
+			&i.Name,
+			&i.City,
+			&i.SpotifyPlaylist,
+			&i.SongkickID,
+			&i.Tags,
+			&i.CreatedAt,
+		); 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
+}
+
+const updateVenueName = `-- name: UpdateVenueName :exec
+UPDATE venue
+SET name = ?
+WHERE slug = ?
+`
+
+type UpdateVenueNameParams struct {
+	Name string `json:"name"`
+	Slug string `json:"slug"`
+}
+
+func (q *Queries) UpdateVenueName(ctx context.Context, arg UpdateVenueNameParams) error {
+	_, err := q.exec(ctx, q.updateVenueNameStmt, updateVenueName, arg.Name, arg.Slug)
+	return err
+}
+
+const venueCountByCity = `-- name: VenueCountByCity :many
+SELECT
+    city,
+    count(*)
+FROM venue
+GROUP BY 1
+ORDER BY 1
+`
+
+type VenueCountByCityRow struct {
+	City  string `json:"city"`
+	Count int64  `json:"count"`
+}
+
+func (q *Queries) VenueCountByCity(ctx context.Context) ([]VenueCountByCityRow, error) {
+	rows, err := q.query(ctx, q.venueCountByCityStmt, venueCountByCity)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []VenueCountByCityRow
+	for rows.Next() {
+		var i VenueCountByCityRow
+		if err := rows.Scan(&i.City, &i.Count); 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/examples/ondeck/city.sql.go b/examples/ondeck/postgresql/city.sql.go
similarity index 100%
rename from examples/ondeck/city.sql.go
rename to examples/ondeck/postgresql/city.sql.go
diff --git a/examples/ondeck/postgresql/db.go b/examples/ondeck/postgresql/db.go
new file mode 100644
index 0000000000..834ca6c41a
--- /dev/null
+++ b/examples/ondeck/postgresql/db.go
@@ -0,0 +1,176 @@
+// Code generated by sqlc. DO NOT EDIT.
+
+package ondeck
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+)
+
+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}
+}
+
+func Prepare(ctx context.Context, db DBTX) (*Queries, error) {
+	q := Queries{db: db}
+	var err error
+	if q.createCityStmt, err = db.PrepareContext(ctx, createCity); err != nil {
+		return nil, fmt.Errorf("error preparing query CreateCity: %w", err)
+	}
+	if q.createVenueStmt, err = db.PrepareContext(ctx, createVenue); err != nil {
+		return nil, fmt.Errorf("error preparing query CreateVenue: %w", err)
+	}
+	if q.deleteVenueStmt, err = db.PrepareContext(ctx, deleteVenue); err != nil {
+		return nil, fmt.Errorf("error preparing query DeleteVenue: %w", err)
+	}
+	if q.getCityStmt, err = db.PrepareContext(ctx, getCity); err != nil {
+		return nil, fmt.Errorf("error preparing query GetCity: %w", err)
+	}
+	if q.getVenueStmt, err = db.PrepareContext(ctx, getVenue); err != nil {
+		return nil, fmt.Errorf("error preparing query GetVenue: %w", err)
+	}
+	if q.listCitiesStmt, err = db.PrepareContext(ctx, listCities); err != nil {
+		return nil, fmt.Errorf("error preparing query ListCities: %w", err)
+	}
+	if q.listVenuesStmt, err = db.PrepareContext(ctx, listVenues); err != nil {
+		return nil, fmt.Errorf("error preparing query ListVenues: %w", err)
+	}
+	if q.updateCityNameStmt, err = db.PrepareContext(ctx, updateCityName); err != nil {
+		return nil, fmt.Errorf("error preparing query UpdateCityName: %w", err)
+	}
+	if q.updateVenueNameStmt, err = db.PrepareContext(ctx, updateVenueName); err != nil {
+		return nil, fmt.Errorf("error preparing query UpdateVenueName: %w", err)
+	}
+	if q.venueCountByCityStmt, err = db.PrepareContext(ctx, venueCountByCity); err != nil {
+		return nil, fmt.Errorf("error preparing query VenueCountByCity: %w", err)
+	}
+	return &q, nil
+}
+
+func (q *Queries) Close() error {
+	var err error
+	if q.createCityStmt != nil {
+		if cerr := q.createCityStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing createCityStmt: %w", cerr)
+		}
+	}
+	if q.createVenueStmt != nil {
+		if cerr := q.createVenueStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing createVenueStmt: %w", cerr)
+		}
+	}
+	if q.deleteVenueStmt != nil {
+		if cerr := q.deleteVenueStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing deleteVenueStmt: %w", cerr)
+		}
+	}
+	if q.getCityStmt != nil {
+		if cerr := q.getCityStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing getCityStmt: %w", cerr)
+		}
+	}
+	if q.getVenueStmt != nil {
+		if cerr := q.getVenueStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing getVenueStmt: %w", cerr)
+		}
+	}
+	if q.listCitiesStmt != nil {
+		if cerr := q.listCitiesStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing listCitiesStmt: %w", cerr)
+		}
+	}
+	if q.listVenuesStmt != nil {
+		if cerr := q.listVenuesStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing listVenuesStmt: %w", cerr)
+		}
+	}
+	if q.updateCityNameStmt != nil {
+		if cerr := q.updateCityNameStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing updateCityNameStmt: %w", cerr)
+		}
+	}
+	if q.updateVenueNameStmt != nil {
+		if cerr := q.updateVenueNameStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing updateVenueNameStmt: %w", cerr)
+		}
+	}
+	if q.venueCountByCityStmt != nil {
+		if cerr := q.venueCountByCityStmt.Close(); cerr != nil {
+			err = fmt.Errorf("error closing venueCountByCityStmt: %w", cerr)
+		}
+	}
+	return err
+}
+
+func (q *Queries) exec(ctx context.Context, stmt *sql.Stmt, query string, args ...interface{}) (sql.Result, error) {
+	switch {
+	case stmt != nil && q.tx != nil:
+		return q.tx.StmtContext(ctx, stmt).ExecContext(ctx, args...)
+	case stmt != nil:
+		return stmt.ExecContext(ctx, args...)
+	default:
+		return q.db.ExecContext(ctx, query, args...)
+	}
+}
+
+func (q *Queries) query(ctx context.Context, stmt *sql.Stmt, query string, args ...interface{}) (*sql.Rows, error) {
+	switch {
+	case stmt != nil && q.tx != nil:
+		return q.tx.StmtContext(ctx, stmt).QueryContext(ctx, args...)
+	case stmt != nil:
+		return stmt.QueryContext(ctx, args...)
+	default:
+		return q.db.QueryContext(ctx, query, args...)
+	}
+}
+
+func (q *Queries) queryRow(ctx context.Context, stmt *sql.Stmt, query string, args ...interface{}) *sql.Row {
+	switch {
+	case stmt != nil && q.tx != nil:
+		return q.tx.StmtContext(ctx, stmt).QueryRowContext(ctx, args...)
+	case stmt != nil:
+		return stmt.QueryRowContext(ctx, args...)
+	default:
+		return q.db.QueryRowContext(ctx, query, args...)
+	}
+}
+
+type Queries struct {
+	db                   DBTX
+	tx                   *sql.Tx
+	createCityStmt       *sql.Stmt
+	createVenueStmt      *sql.Stmt
+	deleteVenueStmt      *sql.Stmt
+	getCityStmt          *sql.Stmt
+	getVenueStmt         *sql.Stmt
+	listCitiesStmt       *sql.Stmt
+	listVenuesStmt       *sql.Stmt
+	updateCityNameStmt   *sql.Stmt
+	updateVenueNameStmt  *sql.Stmt
+	venueCountByCityStmt *sql.Stmt
+}
+
+func (q *Queries) WithTx(tx *sql.Tx) *Queries {
+	return &Queries{
+		db:                   tx,
+		tx:                   tx,
+		createCityStmt:       q.createCityStmt,
+		createVenueStmt:      q.createVenueStmt,
+		deleteVenueStmt:      q.deleteVenueStmt,
+		getCityStmt:          q.getCityStmt,
+		getVenueStmt:         q.getVenueStmt,
+		listCitiesStmt:       q.listCitiesStmt,
+		listVenuesStmt:       q.listVenuesStmt,
+		updateCityNameStmt:   q.updateCityNameStmt,
+		updateVenueNameStmt:  q.updateVenueNameStmt,
+		venueCountByCityStmt: q.venueCountByCityStmt,
+	}
+}
diff --git a/examples/ondeck/db_test.go b/examples/ondeck/postgresql/db_test.go
similarity index 100%
rename from examples/ondeck/db_test.go
rename to examples/ondeck/postgresql/db_test.go
diff --git a/examples/ondeck/models.go b/examples/ondeck/postgresql/models.go
similarity index 100%
rename from examples/ondeck/models.go
rename to examples/ondeck/postgresql/models.go
diff --git a/examples/ondeck/querier.go b/examples/ondeck/postgresql/querier.go
similarity index 100%
rename from examples/ondeck/querier.go
rename to examples/ondeck/postgresql/querier.go
diff --git a/examples/ondeck/query/city.sql b/examples/ondeck/postgresql/query/city.sql
similarity index 100%
rename from examples/ondeck/query/city.sql
rename to examples/ondeck/postgresql/query/city.sql
diff --git a/examples/ondeck/query/venue.sql b/examples/ondeck/postgresql/query/venue.sql
similarity index 100%
rename from examples/ondeck/query/venue.sql
rename to examples/ondeck/postgresql/query/venue.sql
diff --git a/examples/ondeck/schema/0001_city.sql b/examples/ondeck/postgresql/schema/0001_city.sql
similarity index 100%
rename from examples/ondeck/schema/0001_city.sql
rename to examples/ondeck/postgresql/schema/0001_city.sql
diff --git a/examples/ondeck/schema/0002_venue.sql b/examples/ondeck/postgresql/schema/0002_venue.sql
similarity index 100%
rename from examples/ondeck/schema/0002_venue.sql
rename to examples/ondeck/postgresql/schema/0002_venue.sql
diff --git a/examples/ondeck/postgresql/schema/0003_add_column.sql b/examples/ondeck/postgresql/schema/0003_add_column.sql
new file mode 100644
index 0000000000..9b334bccce
--- /dev/null
+++ b/examples/ondeck/postgresql/schema/0003_add_column.sql
@@ -0,0 +1,3 @@
+ALTER TABLE venues RENAME TO venue;
+ALTER TABLE venue ADD COLUMN created_at TIMESTAMP NOT NULL DEFAULT NOW();
+ALTER TABLE venue DROP COLUMN dropped;
diff --git a/examples/ondeck/venue.sql.go b/examples/ondeck/postgresql/venue.sql.go
similarity index 100%
rename from examples/ondeck/venue.sql.go
rename to examples/ondeck/postgresql/venue.sql.go
diff --git a/examples/ondeck/sqlc.json b/examples/ondeck/sqlc.json
index 3b604f4c63..c6abb748d4 100644
--- a/examples/ondeck/sqlc.json
+++ b/examples/ondeck/sqlc.json
@@ -2,14 +2,24 @@
   "version": "1",
   "packages": [
     {
-      "path": ".",
+      "path": "postgresql",
       "name": "ondeck",
-      "schema": "schema",
-      "queries": "query",
+      "schema": "postgresql/schema",
+      "queries": "postgresql/query",
       "engine": "postgresql",
       "emit_json_tags": true,
       "emit_prepared_queries": true,
       "emit_interface": true
+    },
+    {
+      "path": "mysql",
+      "name": "ondeck",
+      "schema": "mysql/schema",
+      "queries": "mysql/query",
+      "engine": "mysql:beta",
+      "emit_json_tags": true,
+      "emit_prepared_queries": true,
+      "emit_interface": true
     }
   ]
 }
diff --git a/internal/compiler/engine.go b/internal/compiler/engine.go
index 3d7d93d8e2..6d579caaa0 100644
--- a/internal/compiler/engine.go
+++ b/internal/compiler/engine.go
@@ -27,7 +27,7 @@ func NewCompiler(conf config.SQL, combo config.CombinedSettings) *Compiler {
 		c.catalog = catalog.New("main")
 	case config.EngineMySQL, config.EngineMySQLBeta:
 		c.parser = dolphin.NewParser()
-		c.catalog = catalog.New("public") // TODO: What is the default database for MySQL?
+		c.catalog = dolphin.NewCatalog()
 	case config.EnginePostgreSQL:
 		c.parser = postgresql.NewParser()
 		c.catalog = postgresql.NewCatalog()
diff --git a/internal/engine/dolphin/catalog.go b/internal/engine/dolphin/catalog.go
new file mode 100644
index 0000000000..4ce1c5f920
--- /dev/null
+++ b/internal/engine/dolphin/catalog.go
@@ -0,0 +1,35 @@
+package dolphin
+
+import (
+	"github.com/kyleconroy/sqlc/internal/sql/ast"
+	"github.com/kyleconroy/sqlc/internal/sql/catalog"
+)
+
+func NewCatalog() *catalog.Catalog {
+	def := "public" // TODO: What is the default database for MySQL?
+	return &catalog.Catalog{
+		DefaultSchema: def,
+		Schemas: []*catalog.Schema{
+			&catalog.Schema{
+				Name: def,
+				Funcs: []*catalog.Function{
+					{
+						Name: "count",
+						Args: []*catalog.Argument{
+							{
+								Type: &ast.TypeName{Name: "any"},
+							},
+						},
+						ReturnType: &ast.TypeName{Name: "bigint"},
+					},
+					{
+						Name:       "count",
+						Args:       []*catalog.Argument{},
+						ReturnType: &ast.TypeName{Name: "bigint"},
+					},
+				},
+			},
+		},
+		Extensions: map[string]struct{}{},
+	}
+}
diff --git a/internal/engine/dolphin/convert.go b/internal/engine/dolphin/convert.go
index 8f8e9c9677..6f56a2cba6 100644
--- a/internal/engine/dolphin/convert.go
+++ b/internal/engine/dolphin/convert.go
@@ -445,8 +445,34 @@ func (c *cc) convertAdminStmt(n *pcast.AdminStmt) ast.Node {
 	return &ast.TODO{}
 }
 
-func (c *cc) convertAggregateFuncExpr(n *pcast.AggregateFuncExpr) ast.Node {
-	return &ast.TODO{}
+func (c *cc) convertAggregateFuncExpr(n *pcast.AggregateFuncExpr) *ast.FuncCall {
+	fn := &ast.FuncCall{
+		Func: &ast.FuncName{
+			Name: n.F,
+		},
+		Funcname: &ast.List{
+			Items: []ast.Node{
+				&ast.String{
+					Str: n.F,
+				},
+			},
+		},
+		Args:     &ast.List{},
+		AggOrder: &ast.List{},
+	}
+	for _, a := range n.Args {
+		if value, ok := a.(*driver.ValueExpr); ok {
+			if value.GetInt64() == int64(1) {
+				fn.AggStar = true
+				continue
+			}
+		}
+		fn.Args.Items = append(fn.Args.Items, c.convert(a))
+	}
+	if n.Distinct {
+		fn.AggDistinct = true
+	}
+	return fn
 }
 
 func (c *cc) convertAlterDatabaseStmt(n *pcast.AlterDatabaseStmt) ast.Node {
diff --git a/internal/engine/dolphin/utils.go b/internal/engine/dolphin/utils.go
index 5783c6e5a6..6bbc315695 100644
--- a/internal/engine/dolphin/utils.go
+++ b/internal/engine/dolphin/utils.go
@@ -76,6 +76,9 @@ func isNotNull(n *pcast.ColumnDef) bool {
 		if n.Options[i].Tp == pcast.ColumnOptionNotNull {
 			return true
 		}
+		if n.Options[i].Tp == pcast.ColumnOptionPrimaryKey {
+			return true
+		}
 	}
 	return false
 }
diff --git a/internal/sqltest/mysql.go b/internal/sqltest/mysql.go
index 781405ab70..d1cf92e6ad 100644
--- a/internal/sqltest/mysql.go
+++ b/internal/sqltest/mysql.go
@@ -50,6 +50,18 @@ func MySQL(t *testing.T, migrations []string) (*sql.DB, func()) {
 		t.Fatal(err)
 	}
 
+	// For each test, pick a new database name at random.
+	dbName := "sqltest_mysql_" + id()
+	if _, err := db.Exec("CREATE DATABASE " + dbName); err != nil {
+		t.Fatal(err)
+	}
+
+	source = fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?multiStatements=true&parseTime=true", user, pass, host, port, dbName)
+	sdb, err := sql.Open("mysql", source)
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	files, err := sqlpath.Glob(migrations)
 	if err != nil {
 		t.Fatal(err)
@@ -59,10 +71,10 @@ func MySQL(t *testing.T, migrations []string) (*sql.DB, func()) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		if _, err := db.Exec(string(blob)); err != nil {
+		if _, err := sdb.Exec(string(blob)); err != nil {
 			t.Fatalf("%s: %s", filepath.Base(f), err)
 		}
 	}
 
-	return db, func() {}
+	return sdb, func() {}
 }
diff --git a/internal/sqltest/postgres.go b/internal/sqltest/postgres.go
index bc5cb8dd2b..f85e933f43 100644
--- a/internal/sqltest/postgres.go
+++ b/internal/sqltest/postgres.go
@@ -66,10 +66,8 @@ func PostgreSQL(t *testing.T, migrations []string) (*sql.DB, func()) {
 		t.Fatal(err)
 	}
 
-	schema := "sqltest_" + id()
-
 	// For each test, pick a new schema name at random.
-	// `foo` is used here only as an example
+	schema := "sqltest_postgresql_" + id()
 	if _, err := db.Exec("CREATE SCHEMA " + schema); err != nil {
 		t.Fatal(err)
 	}