dolphin: Implement simple update statements (#625)

Author: kyleconroy

…al/endtoend/testdata/update_set/go/db.go …dtoend/testdata/update_set/myql/go/db.gointernal/endtoend/testdata/update_set/go/db.go renamed to internal/endtoend/testdata/update_set/myql/go/db.go internal/endtoend/testdata/update_set/go/db.go renamed to internal/endtoend/testdata/update_set/myql/go/db.go

@@ -0,0 +1,4 @@
+CREATE TABLE foo (name text not null, slug text not null);
+
+/* name: UpdateSet :exec */
+UPDATE foo SET name = ? WHERE slug = ?;

…ndtoend/testdata/update_set/go/models.go …nd/testdata/update_set/myql/go/models.gointernal/endtoend/testdata/update_set/go/models.go renamed to internal/endtoend/testdata/update_set/myql/go/models.go internal/endtoend/testdata/update_set/go/models.go renamed to internal/endtoend/testdata/update_set/myql/go/models.go

@@ -2,6 +2,7 @@
   "version": "1",
   "packages": [
     {
+      "engine": "_dolphin",
       "path": "go",
       "name": "querytest",
       "schema": "query.sql",

internal/endtoend/testdata/update_set/myql/go/query.sql.go

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