Fix PG fails (#2957)

* Better support for arrays of objects

* No transaction in class creation

Author: flovilmart

src/Adapters/Storage/Postgres/PostgresStorageAdapter.js

@@ -410,11 +410,8 @@ export class PostgresStorageAdapter {
   }
 
   createClass(className, schema) {
-    return this._client.tx(t => {
-      const q1 = this.createTable(className, schema);
-      const q2 = this._client.none('INSERT INTO "_SCHEMA" ("className", "schema", "isParseClass") VALUES ($<className>, $<schema>, true)', { className, schema });
-
-      return t.batch([q1, q2]);
+    return this.createTable(className, schema).then(() => {
+      return this._client.none('INSERT INTO "_SCHEMA" ("className", "schema", "isParseClass") VALUES ($<className>, $<schema>, true)', { className, schema });
     })
     .then(() => {
       return toParseSchema(schema)
@@ -895,7 +892,14 @@ export class PostgresStorageAdapter {
         if (expectedType === 'text[]') {
           updatePatterns.push(`$${index}:name = $${index + 1}::text[]`);
         } else {
-          updatePatterns.push(`$${index}:name = array_to_json($${index + 1}::text[])::jsonb`);
+          let type = 'text';
+          for (let elt of fieldValue) {
+            if (typeof elt == 'object') {
+              type = 'json';
+              break;
+            }
+          }
+          updatePatterns.push(`$${index}:name = array_to_json($${index + 1}::${type}[])::jsonb`);
         }
         values.push(fieldName, fieldValue);
         index += 2;