Initial add for PDO/PG convert placeholders

4dev/documentation/DB_Query_Params.md

@@ -0,0 +1,31 @@
+# DB Query Params ? and : to $
+
+dbReturn*
+dbExec
+
+keep
+->query
+->params
+for reference
+
+## : named params
+
+in order for each named found replace with order number:
+
+```txt
+:name, :foo, :bar, :name =>
+$1,    $2,   $3,    $1
+```
+
+```php
+$query = str_replace(
+    [':name', ':foo', ':bar'],
+    ['$1', '$2', '$3'],
+    $query
+);
+```
+
+## ? Params
+
+Foreach ? set $1 to $n and store that in new params array
+in QUERY for each ? replace with matching $n