entc/gen: skip Table() predicate and warn about reserved schema nam…

…e (`Client`) (#2486)

* entc/gen: do no generate `Table()` predicate and warn the user in case of reserved schema name like `Client`.

* doc/md: document reserved schema name

* doc/md: revert reserved schema name as this was already working

* doc/md: rephrase

doc/md/schema-def.md

@@ -58,6 +58,12 @@ the root directory of your project, and can be generated by `entc` as follows:
 go run entgo.io/ent/cmd/ent init User Group
 ```
 
+:::note 
+Please note, that some schema names (like `Client`) are not available due to 
+[internal use](https://pkg.go.dev/entgo.io/ent/entc/gen#ValidSchemaName). You can circumvent reserved names by using an 
+annotation as mentioned [here](schema-annotations.md#custom-table-name).
+:::
+
 ## It's Just Another ORM
 
 If you are used to the definition of relations over edges, that's fine.

entc/gen/template/where.tmpl

@@ -41,7 +41,7 @@ func ID(id {{ $.ID.Type }}) predicate.{{ $.Name }} {
 	{{/* JSON cannot be compared using "=" and Enum has a type defined with the field name */}}
 	{{ $hasP := not (or $f.IsJSON $f.IsEnum) }}
 	{{ $comparable := or $f.ConvertedToBasic $f.Type.Valuer }}
-	{{ $undeclared := (and (ne $func "Label") (ne $func "Hooks") (ne $func "Policy")) }}
+	{{ $undeclared := (and (ne $func "Label") (ne $func "Hooks") (ne $func "Policy") (ne $func "Table")) }}
 	{{- if and $hasP $comparable $undeclared }}
 		{{ $arg := "v" }}
 		// {{ $func }} applies equality check predicate on the {{ quote $f.Name }} field. It's identical to {{ $func }}EQ.