fix(engine/mysql): Add support for MySQL ON DUPLICATE KEY UPDATE (#1286)

* fix(engine/mysql): Add support for MySQL ON DUPLICATE KEY UPDATE

* Remove unnecessary action

Author: timstudd

internal/endtoend/testdata/on_duplicate_key_update/mysql/db/db.go

@@ -0,0 +1,13 @@
+-- https://github.com/kyleconroy/sqlc/issues/921
+CREATE TABLE authors (
+  id   BIGINT  NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  name text    NOT NULL,
+  bio  text,
+  UNIQUE(name)
+);
+
+-- name: UpsertAuthor :exec
+INSERT INTO authors (name, bio)
+VALUES (?, ?)
+ON DUPLICATE KEY
+    UPDATE bio = ?;

internal/endtoend/testdata/on_duplicate_key_update/mysql/db/models.go

@@ -0,0 +1,11 @@
+{
+	"version":"1",
+	"packages":[
+		{
+			"path":"db",
+			"engine":"mysql",
+			"schema":"query.sql",
+			"queries":"query.sql"
+		}
+	]
+}

internal/endtoend/testdata/on_duplicate_key_update/mysql/db/query.sql.go

@@ -0,0 +1,12 @@
+-- https://github.com/kyleconroy/sqlc/issues/921
+CREATE TABLE authors (
+  id   BIGSERIAL PRIMARY KEY,
+  name text      NOT NULL UNIQUE,
+  bio  text
+);
+
+-- name: UpsertAuthor :exec
+INSERT INTO authors (name, bio)
+VALUES ($1, $2)
+ON CONFLICT (name) DO UPDATE
+SET bio = $2;

internal/endtoend/testdata/on_duplicate_key_update/mysql/query.sql

@@ -0,0 +1,11 @@
+{
+	"version":"1",
+	"packages":[
+		{
+			"path":"db",
+			"engine":"postgresql",
+			"schema":"query.sql",
+			"queries":"query.sql"
+		}
+	]
+}