entc/gen: skip Table() predicate and warn about reserved schema name (Client)

doc/md/schema-def.md

@@ -58,6 +58,11 @@ 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 
+Pleae note, that `Client` is a reserved Go struct and cannot be used as schema name. For database tables
+named `client`, please use 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/graph.go

@@ -142,8 +142,9 @@ func (f GenerateFunc) Generate(g *Graph) error {
 func NewGraph(c *Config, schemas ...*load.Schema) (g *Graph, err error) {
 	defer catch(&err)
 	g = &Graph{c, make([]*Type, 0, len(schemas)), schemas}
-	for i := range schemas {
-		g.addNode(schemas[i])
+	for _, s := range schemas {
+		check(reservedName(s.Name), "add schema %q", s.Name)
+		g.addNode(s)
 	}
 	for i := range schemas {
 		g.addEdges(schemas[i])
@@ -438,6 +439,17 @@ func resolve(t *Type) error {
 	return nil
 }
 
+var reservedNames = []string{"Client"}
+
+func reservedName(n string) error {
+	for _, rn := range reservedNames {
+		if rn == n {
+			return fmt.Errorf("%q is a reserved name and cannot be used as schema name", n)
+		}
+	}
+	return nil
+}
+
 // Tables returns the schema definitions of SQL tables for the graph.
 func (g *Graph) Tables() (all []*schema.Table, err error) {
 	tables := make(map[string]*schema.Table)

entc/gen/graph_test.go

@@ -130,6 +130,9 @@ func TestNewGraph(t *testing.T) {
 	require.Equal(t2.Edges[5], t2.Edges[6].Ref)
 	require.Equal(map[string]string{"Name": "From"}, t2.Edges[5].Annotations["GQL"])
 	require.Equal(map[string]string{"Name": "To"}, t2.Edges[6].Annotations["GQL"])
+
+	_, err = NewGraph(&Config{Package: "entc/gen", Storage: drivers[0]}, &load.Schema{Name: "Client"})
+	require.EqualError(err, `entc/gen: add schema "Client": "Client" is a reserved name and cannot be used as schema name`)
 }
 
 func TestNewGraphRequiredLoop(t *testing.T) {

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.