feat(dbml): @postgres/@sqlite dialect directives (#19)

Add parseable `@<namespace>[(<target>)]: <args>` directives embedded in DBML.
They are stored losslessly on each object's Metadata, round-trip unchanged
through the DBML writer, and are translated to SQL only by the writer for the
matching dialect.

- models: Directive type + catalog; Metadata map added to Column and Index
- dbml reader: parse and attach directives at database/table/column/index
  level; line-numbered errors; repeatable by default with singleton duplicate
  detection. Fixes a preexisting bug where an `indexes {}` closing brace ended
  the table early, dropping trailing Note: and directive lines.
- dbml writer: re-emit directives at their location; idempotent output
- pgsql writer: PARTITION BY / INHERITS / WITH / TABLESPACE (table),
  STORAGE / COMPRESSION / identity (column), WITH / TABLESPACE (index)
- sqlite writer: WITHOUT ROWID / STRICT (table), COLLATE (column)
- --strict-directives flag on ReaderOptions and WriterOptions
- docs/DBML_DIRECTIVES.md + reader/writer READMEs

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ss2MY5J11cRGwEz86ZXk7d

pkg/writers/dbml/README.md

@@ -137,6 +137,41 @@ indexes {
 }
 ```
 
+### Dialect directives
+
+Dialect directives stored on a model object's `Metadata` (namespace `postgres`,
+`sqlite`, …) are re-emitted verbatim, one line per directive, at the location
+they belong to:
+
+```dbml
+@postgres: search_path myapp
+
+Table myapp.events {
+  id bigint [pk]
+  created_at timestamp [not null]
+  @postgres(id): identity always
+  @postgres: partition by RANGE (created_at)
+  @sqlite: without rowid
+
+  indexes {
+    (created_at) [name: 'idx_events_created']
+    @postgres: with (fillfactor=90)
+  }
+}
+```
+
+| Emitted at | From |
+|------------|------|
+| Before the first table | `Database.Metadata` |
+| After a column line, as `@ns(col): …` | `Column.Metadata` |
+| After an index line, inside `indexes { }` | `Index.Metadata` |
+| After the `indexes` block, before `Note:` | `Table.Metadata` |
+
+Output is deterministic (ordered by namespace, then source line, then args), so a
+`DBML → model → DBML` round-trip is idempotent. See
+[`docs/DBML_DIRECTIVES.md`](../../../docs/DBML_DIRECTIVES.md) for the grammar and
+the list of directives the PostgreSQL and SQLite writers translate to SQL.
+
 ## Type Mapping
 
 | SQL Type | DBML Type |

pkg/writers/dbml/directives.go

@@ -0,0 +1,23 @@
+package dbml
+
+import (
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+)
+
+// directiveLines renders every dialect directive stored in meta back to its DBML
+// source form, one line per directive, each prefixed with indent. When target is
+// non-empty it is emitted as the "(column)" target, e.g.
+// "  @postgres(id): identity always". Order is deterministic (see
+// models.GetDirectives).
+func directiveLines(meta map[string]any, indent, target string) []string {
+	directives := models.GetDirectives(meta)
+	if len(directives) == 0 {
+		return nil
+	}
+
+	lines := make([]string, 0, len(directives))
+	for _, d := range directives {
+		lines = append(lines, indent+models.FormatDirectiveLine(d, target))
+	}
+	return lines
+}

pkg/writers/dbml/directives_test.go

@@ -0,0 +1,97 @@
+package dbml
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	dbmlreader "git.warky.dev/wdevs/relspecgo/pkg/readers/dbml"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/readers"
+	"git.warky.dev/wdevs/relspecgo/pkg/writers"
+)
+
+const directiveSrc = `@postgres: search_path myapp
+
+Table myapp.events {
+  id bigint [pk]
+  created_at timestamp [not null]
+  @postgres(id): identity always
+  @postgres: partition by RANGE (created_at)
+  @postgres: tablespace fast_data
+  @sqlite: without rowid
+
+  indexes {
+    (created_at) [name: 'idx_events_created']
+    @postgres: with (fillfactor=90)
+  }
+}
+`
+
+func writeDBML(t *testing.T, db *models.Database) string {
+	t.Helper()
+	out := filepath.Join(t.TempDir(), "out.dbml")
+	require.NoError(t, NewWriter(&writers.WriterOptions{OutputPath: out}).WriteDatabase(db))
+	b, err := os.ReadFile(out)
+	require.NoError(t, err)
+	return string(b)
+}
+
+func readDBML(t *testing.T, src string) *models.Database {
+	t.Helper()
+	f := filepath.Join(t.TempDir(), "in.dbml")
+	require.NoError(t, os.WriteFile(f, []byte(src), 0o644))
+	db, err := dbmlreader.NewReader(&readers.ReaderOptions{FilePath: f}).ReadDatabase()
+	require.NoError(t, err)
+	return db
+}
+
+func collectDirectives(db *models.Database) map[string][]string {
+	got := map[string][]string{}
+	add := func(loc string, meta map[string]any) {
+		for _, d := range models.GetDirectives(meta) {
+			got[loc] = append(got[loc], models.FormatDirectiveLine(d, ""))
+		}
+	}
+	add("database", db.Metadata)
+	for _, s := range db.Schemas {
+		for _, tbl := range s.Tables {
+			add("table:"+tbl.Name, tbl.Metadata)
+			for _, c := range tbl.Columns {
+				add("column:"+c.Name, c.Metadata)
+			}
+			for _, i := range tbl.Indexes {
+				add("index:"+i.Name, i.Metadata)
+			}
+		}
+	}
+	return got
+}
+
+func TestDirectives_RoundTrip(t *testing.T) {
+	db1 := readDBML(t, directiveSrc)
+	out1 := writeDBML(t, db1)
+	db2 := readDBML(t, out1)
+	out2 := writeDBML(t, db2)
+
+	assert.Equal(t, out1, out2, "DBML directive output should be idempotent")
+	assert.Equal(t, collectDirectives(db1), collectDirectives(db2), "directives preserved through round-trip")
+
+	// Spot-check each location survived.
+	d := collectDirectives(db2)
+	assert.Contains(t, d["database"], "@postgres: search_path myapp")
+	assert.Contains(t, d["table:events"], "@postgres: partition by RANGE (created_at)")
+	assert.Contains(t, d["table:events"], "@sqlite: without rowid")
+	assert.Contains(t, d["column:id"], "@postgres: identity always")
+	assert.Contains(t, d["index:idx_events_created"], "@postgres: with (fillfactor=90)")
+}
+
+func TestDirectives_WriterEmitsColumnTarget(t *testing.T) {
+	db := readDBML(t, directiveSrc)
+	out := writeDBML(t, db)
+	assert.Contains(t, out, "@postgres(id): identity always")
+}

pkg/writers/dbml/writer.go

@@ -72,6 +72,14 @@ func (w *Writer) databaseToDBML(d *models.Database) string {
 		sb.WriteString("\n")
 	}
 
+	if dirLines := directiveLines(d.Metadata, "", ""); len(dirLines) > 0 {
+		for _, line := range dirLines {
+			sb.WriteString(line)
+			sb.WriteString("\n")
+		}
+		sb.WriteString("\n")
+	}
+
 	for _, schema := range d.Schemas {
 		sb.WriteString(w.schemaToDBML(schema))
 	}
@@ -146,6 +154,11 @@ func (w *Writer) tableToDBML(t *models.Table) string {
 			fmt.Fprintf(&sb, " // %s", column.Comment)
 		}
 		sb.WriteString("\n")
+
+		for _, line := range directiveLines(column.Metadata, "  ", column.Name) {
+			sb.WriteString(line)
+			sb.WriteString("\n")
+		}
 	}
 
 	if len(t.Indexes) > 0 {
@@ -167,10 +180,20 @@ func (w *Writer) tableToDBML(t *models.Table) string {
 				fmt.Fprintf(&sb, " [%s]", strings.Join(indexAttrs, ", "))
 			}
 			sb.WriteString("\n")
+
+			for _, line := range directiveLines(index.Metadata, "    ", "") {
+				sb.WriteString(line)
+				sb.WriteString("\n")
+			}
 		}
 		sb.WriteString("  }\n")
 	}
 
+	for _, line := range directiveLines(t.Metadata, "  ", "") {
+		sb.WriteString(line)
+		sb.WriteString("\n")
+	}
+
 	note := strings.TrimSpace(t.Description + " " + t.Comment)
 	if note != "" {
 		fmt.Fprintf(&sb, "\n  Note: '%s'\n", note)

pkg/writers/pgsql/README.md

@@ -172,6 +172,26 @@ When `include_audit` is enabled, adds:
 - Concurrent index creation (`CREATE INDEX CONCURRENTLY`) via `Index.Concurrent`
 - Check constraints with expressions
 - Extension types and indexes: PostGIS, pgvector, citext, hstore, ltree (see below)
+- DBML dialect directives (`@postgres:` — see below)
+
+### DBML dialect directives
+
+`@postgres:` directives carried on a model object's `Metadata` (typically from a
+DBML source file) are translated to SQL:
+
+| Directive | Location | Emitted |
+|-----------|----------|---------|
+| `@postgres: partition by …` | table | `PARTITION BY …` on `CREATE TABLE` |
+| `@postgres: inherits …` | table | `INHERITS (…)` |
+| `@postgres: with (…)` | table, index | `WITH (…)` (on an index, overrides the comment-derived `WITH`) |
+| `@postgres: tablespace …` | table, index | `TABLESPACE …` |
+| `@postgres(col): storage …` | column | `STORAGE …` |
+| `@postgres(col): compression …` | column | `COMPRESSION …` |
+| `@postgres(col): identity always` / `identity by default` | column | `GENERATED ALWAYS/BY DEFAULT AS IDENTITY` |
+
+Directives for other dialects (`@sqlite:` …) are ignored. With
+`WriterOptions.StrictDirectives` (CLI `--strict-directives`) an untranslatable
+`@postgres:` key is an error. Full reference: [`docs/DBML_DIRECTIVES.md`](../../../docs/DBML_DIRECTIVES.md).
 
 ## Data Types
 

pkg/writers/pgsql/directives.go

@@ -0,0 +1,184 @@
+package pgsql
+
+import (
+	"fmt"
+	"strings"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+)
+
+// directiveNamespace is the dialect namespace this writer consumes. Directives
+// for other namespaces (e.g. "sqlite") are ignored and never emitted as SQL.
+const directiveNamespace = "postgres"
+
+// pgHandledDirectives maps a directive location to the set of postgres keys this
+// writer knows how to translate. In strict mode an unknown key for this
+// namespace at a supported location is a hard error.
+var pgHandledDirectives = map[string]map[string]bool{
+	models.DirectiveLocationTable:  {"partition": true, "inherits": true, "with": true, "tablespace": true},
+	models.DirectiveLocationColumn: {"storage": true, "compression": true, "identity": true},
+	models.DirectiveLocationIndex:  {"with": true, "tablespace": true},
+}
+
+// checkDirectives validates postgres directives across a schema when strict mode
+// is enabled. It returns an error for any postgres directive whose key this
+// writer cannot translate. With strict mode off it is a no-op.
+func (w *Writer) checkDirectives(schema *models.Schema) error {
+	if w.options == nil || !w.options.StrictDirectives {
+		return nil
+	}
+	for _, table := range schema.Tables {
+		if err := checkObjectDirectives(table.Metadata, models.DirectiveLocationTable, table.Name); err != nil {
+			return err
+		}
+		for _, col := range table.Columns {
+			if err := checkObjectDirectives(col.Metadata, models.DirectiveLocationColumn, table.Name+"."+col.Name); err != nil {
+				return err
+			}
+		}
+		for _, idx := range table.Indexes {
+			if err := checkObjectDirectives(idx.Metadata, models.DirectiveLocationIndex, idx.Name); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func checkObjectDirectives(meta map[string]any, location, owner string) error {
+	for _, d := range models.DirectivesForNamespace(meta, directiveNamespace) {
+		if !pgHandledDirectives[location][d.Key] {
+			return fmt.Errorf("pgsql: %s: unsupported @postgres directive %q at %s level (strict mode)", owner, d.Key, location)
+		}
+	}
+	return nil
+}
+
+// upperLeadingClause upcases a known leading keyword phrase in a directive
+// argument so the emitted SQL reads conventionally. Identifiers that follow are
+// left untouched.
+func upperLeadingClause(args, lowerPrefix, upperPrefix string) string {
+	args = strings.TrimSpace(args)
+	if strings.HasPrefix(strings.ToLower(args), lowerPrefix) {
+		return upperPrefix + args[len(lowerPrefix):]
+	}
+	return args
+}
+
+// pgTableDirectiveSuffix returns the clause appended after the closing ")" of a
+// CREATE TABLE statement, e.g. " PARTITION BY RANGE (created_at) TABLESPACE fast".
+func pgTableDirectiveSuffix(table *models.Table) string {
+	directives := models.DirectivesForNamespace(table.Metadata, directiveNamespace)
+	if len(directives) == 0 {
+		return ""
+	}
+
+	byKey := firstByKey(directives)
+
+	var parts []string
+	if d, ok := byKey["partition"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "partition by", "PARTITION BY"))
+	}
+	if d, ok := byKey["inherits"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "inherits", "INHERITS"))
+	}
+	if d, ok := byKey["with"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "with", "WITH"))
+	}
+	if d, ok := byKey["tablespace"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "tablespace", "TABLESPACE"))
+	}
+	if len(parts) == 0 {
+		return ""
+	}
+	return " " + strings.Join(parts, " ")
+}
+
+// pgColumnDirectiveSuffix returns the clause appended to a column definition,
+// e.g. " STORAGE PLAIN" or " GENERATED ALWAYS AS IDENTITY".
+func pgColumnDirectiveSuffix(col *models.Column) string {
+	directives := models.DirectivesForNamespace(col.Metadata, directiveNamespace)
+	if len(directives) == 0 {
+		return ""
+	}
+	byKey := firstByKey(directives)
+
+	var parts []string
+	if d, ok := byKey["storage"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "storage", "STORAGE"))
+	}
+	if d, ok := byKey["compression"]; ok {
+		parts = append(parts, upperLeadingClause(d.Args, "compression", "COMPRESSION"))
+	}
+	if d, ok := byKey["identity"]; ok {
+		parts = append(parts, identityClause(d.Args))
+	}
+	if len(parts) == 0 {
+		return ""
+	}
+	return " " + strings.Join(parts, " ")
+}
+
+// identityClause maps the two documented identity forms to standard SQL,
+// falling back to a verbatim (upcased-keyword) rendering.
+func identityClause(args string) string {
+	switch strings.ToLower(strings.Join(strings.Fields(args), " ")) {
+	case "identity always":
+		return "GENERATED ALWAYS AS IDENTITY"
+	case "identity default", "identity by default":
+		return "GENERATED BY DEFAULT AS IDENTITY"
+	default:
+		return upperLeadingClause(args, "identity", "IDENTITY")
+	}
+}
+
+// pgIndexDirectiveWith returns the parenthesised storage-parameter list from an
+// @postgres: with (...) index directive, e.g. "fillfactor=90", or "".
+func pgIndexDirectiveWith(index *models.Index) string {
+	for _, d := range models.DirectivesForNamespace(index.Metadata, directiveNamespace) {
+		if d.Key != "with" {
+			continue
+		}
+		inner := d.Args
+		if i := strings.Index(inner, "("); i >= 0 {
+			if j := strings.LastIndex(inner, ")"); j > i {
+				return strings.TrimSpace(inner[i+1 : j])
+			}
+		}
+		return strings.TrimSpace(strings.TrimPrefix(strings.ToLower(inner), "with"))
+	}
+	return ""
+}
+
+// pgIndexWithParams returns the storage-parameter list to use for an index,
+// preferring an @postgres: with (...) directive over the given fallback (e.g.
+// one derived from the index comment).
+func pgIndexWithParams(index *models.Index, fallback string) string {
+	if p := pgIndexDirectiveWith(index); p != "" {
+		return p
+	}
+	return fallback
+}
+
+// pgIndexDirectiveTablespace returns the tablespace name from an
+// @postgres: tablespace <name> index directive, or "".
+func pgIndexDirectiveTablespace(index *models.Index) string {
+	for _, d := range models.DirectivesForNamespace(index.Metadata, directiveNamespace) {
+		if d.Key == "tablespace" {
+			return strings.TrimSpace(strings.TrimPrefix(strings.ToLower(d.Args), "tablespace"))
+		}
+	}
+	return ""
+}
+
+// firstByKey indexes directives by key, keeping the first occurrence (the
+// documented postgres keys used here are all singletons).
+func firstByKey(directives []models.Directive) map[string]models.Directive {
+	byKey := make(map[string]models.Directive, len(directives))
+	for _, d := range directives {
+		if _, exists := byKey[d.Key]; !exists {
+			byKey[d.Key] = d
+		}
+	}
+	return byKey
+}

pkg/writers/pgsql/directives_test.go

@@ -0,0 +1,107 @@
+package pgsql
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/writers"
+)
+
+func directiveTestDB(t *testing.T) *models.Database {
+	t.Helper()
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+	table := models.InitTable("events", "public")
+
+	id := models.InitColumn("id", "events", "public")
+	id.Type = "bigint"
+	id.IsPrimaryKey = true
+	id.NotNull = true
+	models.AddDirective(id.Metadata, models.Directive{Namespace: "postgres", Args: "identity always"})
+	models.AddDirective(id.Metadata, models.Directive{Namespace: "sqlite", Args: "collate NOCASE"})
+	table.Columns["id"] = id
+
+	created := models.InitColumn("created_at", "events", "public")
+	created.Type = "timestamp"
+	created.NotNull = true
+	table.Columns["created_at"] = created
+
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "postgres", Args: "partition by RANGE (created_at)"})
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "postgres", Args: "tablespace fast_data"})
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "sqlite", Args: "without rowid"})
+
+	idx := models.InitIndex("idx_events_created", "events", "public")
+	idx.Columns = []string{"created_at"}
+	models.AddDirective(idx.Metadata, models.Directive{Namespace: "postgres", Args: "with (fillfactor=90)"})
+	models.AddDirective(idx.Metadata, models.Directive{Namespace: "postgres", Args: "tablespace idx_space"})
+	table.Indexes["idx_events_created"] = idx
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+	return db
+}
+
+func TestPgDirectives_WriteDatabasePath(t *testing.T) {
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{})
+	w.writer = &buf
+	if err := w.WriteDatabase(directiveTestDB(t)); err != nil {
+		t.Fatalf("WriteDatabase: %v", err)
+	}
+	out := buf.String()
+
+	for _, want := range []string{
+		") PARTITION BY RANGE (created_at) TABLESPACE fast_data",
+		"GENERATED ALWAYS AS IDENTITY",
+		"WITH (fillfactor=90) TABLESPACE idx_space",
+	} {
+		if !strings.Contains(out, want) {
+			t.Errorf("missing %q in:\n%s", want, out)
+		}
+	}
+	// sqlite directives must never reach PG output.
+	if strings.Contains(out, "WITHOUT ROWID") || strings.Contains(strings.ToUpper(out), "COLLATE NOCASE") {
+		t.Errorf("sqlite directive leaked into PG output:\n%s", out)
+	}
+}
+
+func TestPgDirectives_WriteSchemaPath(t *testing.T) {
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{})
+	w.writer = &buf
+	if err := w.WriteSchema(directiveTestDB(t).Schemas[0]); err != nil {
+		t.Fatalf("WriteSchema: %v", err)
+	}
+	out := buf.String()
+	if !strings.Contains(out, ") PARTITION BY RANGE (created_at) TABLESPACE fast_data;") {
+		t.Errorf("table suffix missing from WriteSchema path:\n%s", out)
+	}
+	if !strings.Contains(out, "WITH (fillfactor=90) TABLESPACE idx_space") {
+		t.Errorf("index clauses missing from WriteSchema path:\n%s", out)
+	}
+}
+
+func TestPgDirectives_StrictUnknownKeyErrors(t *testing.T) {
+	db := directiveTestDB(t)
+	models.AddDirective(db.Schemas[0].Tables[0].Metadata, models.Directive{Namespace: "postgres", Args: "frobnicate x"})
+
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{StrictDirectives: true})
+	w.writer = &buf
+	err := w.WriteSchema(db.Schemas[0])
+	if err == nil || !strings.Contains(err.Error(), "frobnicate") {
+		t.Fatalf("want strict error for unknown postgres key, got %v", err)
+	}
+}
+
+func TestPgDirectives_StrictIgnoresOtherNamespaces(t *testing.T) {
+	// sqlite directives are present but must not trip PG strict mode.
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{StrictDirectives: true})
+	w.writer = &buf
+	if err := w.WriteSchema(directiveTestDB(t).Schemas[0]); err != nil {
+		t.Fatalf("strict mode should ignore non-postgres directives, got %v", err)
+	}
+}

pkg/writers/pgsql/writer.go

@@ -143,6 +143,10 @@ func (w *Writer) GenerateDatabaseStatements(db *models.Database) ([]string, erro
 func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, error) {
 	statements := []string{}
 
+	if err := w.checkDirectives(schema); err != nil {
+		return nil, err
+	}
+
 	// Phase 1: Create schema (skip entirely when flattening)
 	if schema.Name != "public" && !w.options.FlattenSchema {
 		statements = append(statements, fmt.Sprintf("-- Schema: %s", schema.Name))
@@ -277,17 +281,22 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 			columnExprs := buildIndexColumnExpressions(table, index, indexType)
 
 			withClause := ""
-			if params := indexStorageParameters(index.Comment); params != "" {
+			if params := pgIndexWithParams(index, indexStorageParameters(index.Comment)); params != "" {
 				withClause = fmt.Sprintf(" WITH (%s)", params)
 			}
 
+			tablespaceClause := ""
+			if ts := pgIndexDirectiveTablespace(index); ts != "" {
+				tablespaceClause = fmt.Sprintf(" TABLESPACE %s", ts)
+			}
+
 			whereClause := ""
 			if index.Where != "" {
 				whereClause = fmt.Sprintf(" WHERE %s", index.Where)
 			}
 
-			stmt := fmt.Sprintf("CREATE %sINDEX IF NOT EXISTS %s ON %s USING %s (%s)%s%s",
-				uniqueStr, quoteIdentifier(index.Name), w.qualTable(schema.SQLName(), table.SQLName()), indexType, strings.Join(columnExprs, ", "), withClause, whereClause)
+			stmt := fmt.Sprintf("CREATE %sINDEX IF NOT EXISTS %s ON %s USING %s (%s)%s%s%s",
+				uniqueStr, quoteIdentifier(index.Name), w.qualTable(schema.SQLName(), table.SQLName()), indexType, strings.Join(columnExprs, ", "), withClause, tablespaceClause, whereClause)
 			statements = append(statements, stmt)
 		}
 	}
@@ -581,8 +590,9 @@ func (w *Writer) generateCreateTableStatement(schema *models.Schema, table *mode
 		columnDefs = append(columnDefs, "  "+def)
 	}
 
-	stmt := fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (\n%s\n)",
-		w.qualTable(schema.SQLName(), table.SQLName()), strings.Join(columnDefs, ",\n"))
+	stmt := fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (\n%s\n)%s",
+		w.qualTable(schema.SQLName(), table.SQLName()), strings.Join(columnDefs, ",\n"),
+		pgTableDirectiveSuffix(table))
 	statements = append(statements, stmt)
 
 	return statements, nil
@@ -611,7 +621,7 @@ func (w *Writer) generateColumnDefinition(col *models.Column) string {
 		}
 	}
 
-	return strings.Join(parts, " ")
+	return strings.Join(parts, " ") + pgColumnDirectiveSuffix(col)
 }
 
 func effectiveColumnSQLType(col *models.Column) string {
@@ -678,6 +688,10 @@ func (w *Writer) WriteSchema(schema *models.Schema) error {
 		w.writer = os.Stdout
 	}
 
+	if err := w.checkDirectives(schema); err != nil {
+		return err
+	}
+
 	// Phase 1: Create schema (priority 1)
 	if err := w.writeCreateSchema(schema); err != nil {
 		return err
@@ -884,7 +898,7 @@ func (w *Writer) writeCreateTables(schema *models.Schema) error {
 		}
 
 		fmt.Fprintf(w.writer, "%s\n", strings.Join(columnDefs, ",\n"))
-		fmt.Fprintf(w.writer, ");\n\n")
+		fmt.Fprintf(w.writer, ")%s;\n\n", pgTableDirectiveSuffix(table))
 	}
 
 	return nil
@@ -1079,10 +1093,15 @@ func (w *Writer) writeIndexes(schema *models.Schema) error {
 			}
 
 			withClause := ""
-			if params := indexStorageParameters(index.Comment); params != "" {
+			if params := pgIndexWithParams(index, indexStorageParameters(index.Comment)); params != "" {
 				withClause = fmt.Sprintf(" WITH (%s)", params)
 			}
 
+			tablespaceClause := ""
+			if ts := pgIndexDirectiveTablespace(index); ts != "" {
+				tablespaceClause = fmt.Sprintf(" TABLESPACE %s", ts)
+			}
+
 			whereClause := ""
 			if index.Where != "" {
 				whereClause = fmt.Sprintf(" WHERE %s", index.Where)
@@ -1095,8 +1114,8 @@ func (w *Writer) writeIndexes(schema *models.Schema) error {
 
 			fmt.Fprintf(w.writer, "CREATE %sINDEX %sIF NOT EXISTS %s\n",
 				unique, concurrently, indexName)
-			fmt.Fprintf(w.writer, "  ON %s USING %s (%s)%s%s;\n\n",
-				w.qualTable(schema.SQLName(), table.SQLName()), indexType, strings.Join(columnExprs, ", "), withClause, whereClause)
+			fmt.Fprintf(w.writer, "  ON %s USING %s (%s)%s%s%s;\n\n",
+				w.qualTable(schema.SQLName(), table.SQLName()), indexType, strings.Join(columnExprs, ", "), withClause, tablespaceClause, whereClause)
 		}
 	}
 

pkg/writers/sqlite/README.md

@@ -118,6 +118,21 @@ CREATE TABLE "posts" (
 - **Check Constraints**: Generated as comments (should be added to CREATE TABLE manually)
 - **Indexes**: Generated without PostgreSQL-specific features (no GIN, GiST, operator classes)
 
+## DBML dialect directives
+
+`@sqlite:` directives carried on a model object's `Metadata` (typically from a
+DBML source file) are translated to SQL:
+
+| Directive | Location | Emitted |
+|-----------|----------|---------|
+| `@sqlite: without rowid` | table | `WITHOUT ROWID` table option |
+| `@sqlite: strict` | table | `STRICT` table option (after `WITHOUT ROWID`) |
+| `@sqlite(col): collate …` | column | ` COLLATE …` in the column definition |
+
+Directives for other dialects (`@postgres:` …) are ignored. With
+`WriterOptions.StrictDirectives` (CLI `--strict-directives`) an untranslatable
+`@sqlite:` key is an error. Full reference: [`docs/DBML_DIRECTIVES.md`](../../../docs/DBML_DIRECTIVES.md).
+
 ## Output Structure
 
 Generated SQL follows this order:

pkg/writers/sqlite/directives.go

@@ -0,0 +1,84 @@
+package sqlite
+
+import (
+	"fmt"
+	"strings"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+)
+
+// directiveNamespace is the dialect namespace this writer consumes. Directives
+// for other namespaces (e.g. "postgres") are ignored and never emitted as SQL.
+const directiveNamespace = "sqlite"
+
+// sqliteHandledDirectives maps a directive location to the set of sqlite keys
+// this writer knows how to translate. In strict mode an unknown key for this
+// namespace at a supported location is a hard error.
+var sqliteHandledDirectives = map[string]map[string]bool{
+	models.DirectiveLocationTable:  {"without": true, "strict": true},
+	models.DirectiveLocationColumn: {"collate": true},
+}
+
+// checkDirectives validates sqlite directives across a schema when strict mode
+// is enabled. With strict mode off it is a no-op.
+func (w *Writer) checkDirectives(schema *models.Schema) error {
+	if w.options == nil || !w.options.StrictDirectives {
+		return nil
+	}
+	for _, table := range schema.Tables {
+		if err := checkObjectDirectives(table.Metadata, models.DirectiveLocationTable, table.Name); err != nil {
+			return err
+		}
+		for _, col := range table.Columns {
+			if err := checkObjectDirectives(col.Metadata, models.DirectiveLocationColumn, table.Name+"."+col.Name); err != nil {
+				return err
+			}
+		}
+		for _, idx := range table.Indexes {
+			if err := checkObjectDirectives(idx.Metadata, models.DirectiveLocationIndex, idx.Name); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func checkObjectDirectives(meta map[string]any, location, owner string) error {
+	for _, d := range models.DirectivesForNamespace(meta, directiveNamespace) {
+		if !sqliteHandledDirectives[location][d.Key] {
+			return fmt.Errorf("sqlite: %s: unsupported @sqlite directive %q at %s level (strict mode)", owner, d.Key, location)
+		}
+	}
+	return nil
+}
+
+// sqliteTableOptions returns the trailing table-option clause for a CREATE TABLE
+// statement, e.g. "WITHOUT ROWID, STRICT". WITHOUT ROWID is emitted before
+// STRICT, matching SQLite's own grammar ordering.
+func sqliteTableOptions(table *models.Table) string {
+	var opts []string
+	if models.HasDirective(table.Metadata, directiveNamespace, "without") {
+		opts = append(opts, "WITHOUT ROWID")
+	}
+	if models.HasDirective(table.Metadata, directiveNamespace, "strict") {
+		opts = append(opts, "STRICT")
+	}
+	return strings.Join(opts, ", ")
+}
+
+// sqliteColumnCollate returns a " COLLATE <name>" clause for a column carrying an
+// @sqlite(col): collate <name> directive, or "".
+func sqliteColumnCollate(col *models.Column) string {
+	for _, d := range models.DirectivesForNamespace(col.Metadata, directiveNamespace) {
+		if d.Key != "collate" {
+			continue
+		}
+		name := strings.TrimSpace(strings.TrimPrefix(strings.TrimSpace(d.Args), "collate"))
+		name = strings.TrimSpace(name)
+		if name == "" {
+			return ""
+		}
+		return " COLLATE " + name
+	}
+	return ""
+}

pkg/writers/sqlite/directives_test.go

@@ -0,0 +1,82 @@
+package sqlite
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/writers"
+)
+
+func sqliteDirectiveDB(t *testing.T) *models.Database {
+	t.Helper()
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+	table := models.InitTable("events", "public")
+
+	id := models.InitColumn("id", "events", "public")
+	id.Type = "bigint"
+	id.IsPrimaryKey = true
+	id.NotNull = true
+	table.Columns["id"] = id
+
+	name := models.InitColumn("name", "events", "public")
+	name.Type = "varchar(200)"
+	name.NotNull = true
+	models.AddDirective(name.Metadata, models.Directive{Namespace: "sqlite", Args: "collate NOCASE"})
+	// A postgres directive on the same column must be ignored by the sqlite writer.
+	models.AddDirective(name.Metadata, models.Directive{Namespace: "postgres", Args: "storage plain"})
+	table.Columns["name"] = name
+
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "sqlite", Args: "without rowid"})
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "sqlite", Args: "strict"})
+	models.AddDirective(table.Metadata, models.Directive{Namespace: "postgres", Args: "partition by RANGE (id)"})
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+	return db
+}
+
+func TestSqliteDirectives_TableOptionsAndCollate(t *testing.T) {
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{})
+	w.writer = &buf
+	if err := w.WriteDatabase(sqliteDirectiveDB(t)); err != nil {
+		t.Fatalf("WriteDatabase: %v", err)
+	}
+	out := buf.String()
+
+	if !strings.Contains(out, ") WITHOUT ROWID, STRICT;") {
+		t.Errorf("missing table options clause:\n%s", out)
+	}
+	if !strings.Contains(out, `"name" TEXT COLLATE NOCASE NOT NULL`) {
+		t.Errorf("missing column COLLATE clause:\n%s", out)
+	}
+	// postgres directives must never reach sqlite output.
+	if strings.Contains(strings.ToUpper(out), "PARTITION BY") || strings.Contains(strings.ToUpper(out), "STORAGE PLAIN") {
+		t.Errorf("postgres directive leaked into sqlite output:\n%s", out)
+	}
+}
+
+func TestSqliteDirectives_StrictUnknownKeyErrors(t *testing.T) {
+	db := sqliteDirectiveDB(t)
+	models.AddDirective(db.Schemas[0].Tables[0].Metadata, models.Directive{Namespace: "sqlite", Args: "frobnicate x"})
+
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{StrictDirectives: true})
+	w.writer = &buf
+	err := w.WriteDatabase(db)
+	if err == nil || !strings.Contains(err.Error(), "frobnicate") {
+		t.Fatalf("want strict error for unknown sqlite key, got %v", err)
+	}
+}
+
+func TestSqliteDirectives_StrictIgnoresPostgres(t *testing.T) {
+	var buf bytes.Buffer
+	w := NewWriter(&writers.WriterOptions{StrictDirectives: true})
+	w.writer = &buf
+	if err := w.WriteDatabase(sqliteDirectiveDB(t)); err != nil {
+		t.Fatalf("strict mode should ignore postgres directives, got %v", err)
+	}
+}

pkg/writers/sqlite/template_functions.go

@@ -22,9 +22,10 @@ func GetTemplateFuncs(opts *writers.WriterOptions) template.FuncMap {
 		"format_constraint_name": func(schema, table, constraint string) string {
 			return FormatConstraintName(schema, table, constraint, opts)
 		},
-		"join":  strings.Join,
-		"lower": strings.ToLower,
-		"upper": strings.ToUpper,
+		"join":           strings.Join,
+		"lower":          strings.ToLower,
+		"upper":          strings.ToUpper,
+		"column_collate": sqliteColumnCollate,
 	}
 }
 

pkg/writers/sqlite/templates.go

@@ -40,11 +40,12 @@ func NewTemplateExecutor(opts *writers.WriterOptions) (*TemplateExecutor, error)
 
 // TableTemplateData contains data for table template
 type TableTemplateData struct {
-	Schema      string
-	Name        string
-	Columns     []*models.Column
-	PrimaryKey  *models.Constraint
-	ForeignKeys []ForeignKeyTemplateData
+	Schema       string
+	Name         string
+	Columns      []*models.Column
+	PrimaryKey   *models.Constraint
+	ForeignKeys  []ForeignKeyTemplateData
+	TableOptions string
 }
 
 // ForeignKeyTemplateData contains data for an inline FOREIGN KEY clause
@@ -188,11 +189,12 @@ func BuildTableTemplateData(schema string, table *models.Table) TableTemplateDat
 	}
 
 	return TableTemplateData{
-		Schema:      schema,
-		Name:        table.Name,
-		Columns:     columns,
-		PrimaryKey:  pk,
-		ForeignKeys: fks,
+		Schema:       schema,
+		Name:         table.Name,
+		Columns:      columns,
+		PrimaryKey:   pk,
+		ForeignKeys:  fks,
+		TableOptions: sqliteTableOptions(table),
 	}
 }
 

pkg/writers/sqlite/templates/create_table.tmpl

@@ -1,7 +1,7 @@
 CREATE TABLE {{quote_ident (qualified_table_name .Schema .Name)}} (
 {{- $hasAutoIncrement := false}}
 {{- range $i, $col := .Columns}}{{if $i}},{{end}}
-    {{quote_ident $col.Name}} {{map_type $col.Type}}{{if is_autoincrement $col}}{{$hasAutoIncrement = true}} PRIMARY KEY AUTOINCREMENT{{else}}{{if $col.NotNull}} NOT NULL{{end}}{{if ne (format_default $col) ""}} DEFAULT {{format_default $col}}{{end}}{{end}}
+    {{quote_ident $col.Name}} {{map_type $col.Type}}{{column_collate $col}}{{if is_autoincrement $col}}{{$hasAutoIncrement = true}} PRIMARY KEY AUTOINCREMENT{{else}}{{if $col.NotNull}} NOT NULL{{end}}{{if ne (format_default $col) ""}} DEFAULT {{format_default $col}}{{end}}{{end}}
 {{- end}}
 {{- if and .PrimaryKey (not $hasAutoIncrement)}}{{if gt (len .Columns) 0}},{{end}}
     PRIMARY KEY ({{range $i, $colName := .PrimaryKey.Columns}}{{if $i}}, {{end}}{{quote_ident $colName}}{{end}})
@@ -9,4 +9,4 @@ CREATE TABLE {{quote_ident (qualified_table_name .Schema .Name)}} (
 {{- range .ForeignKeys}},
     FOREIGN KEY ({{range $i, $col := .Columns}}{{if $i}}, {{end}}{{quote_ident $col}}{{end}}) REFERENCES {{quote_ident (qualified_table_name .ForeignSchema .ForeignTable)}} ({{range $i, $col := .ForeignColumns}}{{if $i}}, {{end}}{{quote_ident $col}}{{end}}){{if .OnDelete}} ON DELETE {{.OnDelete}}{{end}}{{if .OnUpdate}} ON UPDATE {{.OnUpdate}}{{end}}
 {{- end}}
-);
+){{if .TableOptions}} {{.TableOptions}}{{end}};

pkg/writers/sqlite/writer.go

@@ -186,6 +186,10 @@ func tableSchemaName(schema string) string {
 func (w *Writer) WriteSchema(schema *models.Schema) error {
 	tableSchema := tableSchemaName(schema.Name)
 
+	if err := w.checkDirectives(schema); err != nil {
+		return err
+	}
+
 	// SQLite doesn't have schemas, so we just write a comment (skip for the
 	// default schema, since its tables aren't actually being prefixed)
 	if tableSchema != "" {

pkg/writers/writer.go

@@ -86,6 +86,10 @@ type WriterOptions struct {
 	// Prisma7 enables Prisma 7-specific output for Prisma writers.
 	Prisma7 bool
 
+	// StrictDirectives makes dialect directive translation fail on an
+	// unsupported key for the writer's own namespace instead of skipping it.
+	StrictDirectives bool
+
 	// ContinueOnError instructs SQL writers to prepend `\set ON_ERROR_STOP off`
 	// to their output so that psql continues past errors instead of stopping.
 	ContinueOnError bool