diff --git a/internal/gen.go b/internal/gen.go
index f88ae2c..f263baf 100644
--- a/internal/gen.go
+++ b/internal/gen.go
@@ -124,9 +124,40 @@ func Generate(ctx context.Context, req *plugin.GenerateRequest) (*plugin.Generat
 		enums, structs = filterUnusedStructs(enums, structs, queries)
 	}
 
+	if err := validate(options, enums, structs, queries); err != nil {
+		return nil, err
+	}
+
 	return generate(req, options, enums, structs, queries)
 }
 
+func validate(options *opts.Options, enums []Enum, structs []Struct, queries []Query) error {
+	enumNames := make(map[string]struct{})
+	for _, enum := range enums {
+		enumNames[enum.Name] = struct{}{}
+		enumNames["Null"+enum.Name] = struct{}{}
+	}
+	structNames := make(map[string]struct{})
+	for _, struckt := range structs {
+		if _, ok := enumNames[struckt.Name]; ok {
+			return fmt.Errorf("struct name conflicts with enum name: %s", struckt.Name)
+		}
+		structNames[struckt.Name] = struct{}{}
+	}
+	if !options.EmitExportedQueries {
+		return nil
+	}
+	for _, query := range queries {
+		if _, ok := enumNames[query.ConstantName]; ok {
+			return fmt.Errorf("query constant name conflicts with enum name: %s", query.ConstantName)
+		}
+		if _, ok := structNames[query.ConstantName]; ok {
+			return fmt.Errorf("query constant name conflicts with struct name: %s", query.ConstantName)
+		}
+	}
+	return nil
+}
+
 func generate(req *plugin.GenerateRequest, options *opts.Options, enums []Enum, structs []Struct, queries []Query) (*plugin.GenerateResponse, error) {
 	i := &importer{
 		Options: options,
diff --git a/internal/result.go b/internal/result.go
index d0ed307..714b1e1 100644
--- a/internal/result.go
+++ b/internal/result.go
@@ -312,16 +312,16 @@ func buildQueries(req *plugin.GenerateRequest, options *opts.Options, structs []
 	return qs, nil
 }
 
+var cmdReturnsData = map[string]struct{}{
+	metadata.CmdBatchMany: {},
+	metadata.CmdBatchOne:  {},
+	metadata.CmdMany:      {},
+	metadata.CmdOne:       {},
+}
+
 func putOutColumns(query *plugin.Query) bool {
-	if len(query.Columns) > 0 {
-		return true
-	}
-	for _, allowed := range []string{metadata.CmdMany, metadata.CmdOne, metadata.CmdBatchMany} {
-		if query.Cmd == allowed {
-			return true
-		}
-	}
-	return false
+	_, found := cmdReturnsData[query.Cmd]
+	return found
 }
 
 // It's possible that this method will generate duplicate JSON tag values
diff --git a/internal/result_test.go b/internal/result_test.go
index be30e1e..fd8bd11 100644
--- a/internal/result_test.go
+++ b/internal/result_test.go
@@ -50,7 +50,7 @@ func TestPutOutColumns_ForZeroColumns(t *testing.T) {
 		},
 		{
 			cmd:  metadata.CmdBatchOne,
-			want: false,
+			want: true,
 		},
 	}
 	for _, tc := range tests {