orm(PostgreSQLDialect): double-quote column names in INSERT field lists

src/orm/dialect/PostgreSQLDialect.ts

@@ -230,7 +230,7 @@ export class PostgreSQLDialect extends SQLDialect {
             const table: string = tableString.split('.').map(x => `"${x}"`)
                 .join('.')
             queryLines.push('INSERT INTO ' + (typeof source === 'string' ? table : `${table} AS "${source.alias}"`)
-                + (columns.length ? ` (${columns.join(', ')})` : ''))
+                + (columns.length ? ` (${columns.map(x => `"${x}"`).join(', ')})` : ''))
         }
 
         if ( Array.isArray(data) && !data.length ) {