feat(writer): 🎉 Add support for check constraints in schema generation

* Implement check constraints in the schema writer.
* Generate SQL statements to add check constraints if they do not exist.
* Add tests to verify correct generation of check constraints.

pkg/readers/dbml/reader.go

@@ -604,7 +604,7 @@ func (r *Reader) parseColumn(line, tableName, schemaName string) (*models.Column
 				} else if attr == "unique" {
 					// Create a unique constraint
 					uniqueConstraint := models.InitConstraint(
-						fmt.Sprintf("uq_%s", columnName),
+						fmt.Sprintf("uq_%s_%s", tableName, columnName),
 						models.UniqueConstraint,
 					)
 					uniqueConstraint.Schema = schemaName
@@ -652,8 +652,8 @@ func (r *Reader) parseColumn(line, tableName, schemaName string) (*models.Column
 							constraint.Table = tableName
 							constraint.Columns = []string{columnName}
 						}
-						// Generate short constraint name based on the column
-						constraint.Name = fmt.Sprintf("fk_%s", constraint.Columns[0])
+						// Generate constraint name based on table and columns
+						constraint.Name = fmt.Sprintf("fk_%s_%s", constraint.Table, strings.Join(constraint.Columns, "_"))
 					}
 				}
 			}
@@ -737,7 +737,11 @@ func (r *Reader) parseIndex(line, tableName, schemaName string) *models.Index {
 
 	// Generate name if not provided
 	if index.Name == "" {
-		index.Name = fmt.Sprintf("idx_%s_%s", tableName, strings.Join(columns, "_"))
+		prefix := "idx"
+		if index.Unique {
+			prefix = "uidx"
+		}
+		index.Name = fmt.Sprintf("%s_%s_%s", prefix, tableName, strings.Join(columns, "_"))
 	}
 
 	return index
@@ -797,10 +801,10 @@ func (r *Reader) parseRef(refStr string) *models.Constraint {
 		return nil
 	}
 
-	// Generate short constraint name based on the source column
-	constraintName := fmt.Sprintf("fk_%s_%s", fromTable, toTable)
-	if len(fromColumns) > 0 {
-		constraintName = fmt.Sprintf("fk_%s", fromColumns[0])
+	// Generate constraint name based on table and columns
+	constraintName := fmt.Sprintf("fk_%s_%s", fromTable, strings.Join(fromColumns, "_"))
+	if len(fromColumns) == 0 {
+		constraintName = fmt.Sprintf("fk_%s_%s", fromTable, toTable)
 	}
 
 	constraint := models.InitConstraint(

pkg/readers/dbml/reader_test.go

@@ -777,6 +777,76 @@ func TestParseFilePrefix(t *testing.T) {
 	}
 }
 
+func TestConstraintNaming(t *testing.T) {
+	// Test that constraints are named with proper prefixes
+	opts := &readers.ReaderOptions{
+		FilePath: filepath.Join("..", "..", "..", "tests", "assets", "dbml", "complex.dbml"),
+	}
+
+	reader := NewReader(opts)
+	db, err := reader.ReadDatabase()
+	if err != nil {
+		t.Fatalf("ReadDatabase() error = %v", err)
+	}
+
+	// Find users table
+	var usersTable *models.Table
+	var postsTable *models.Table
+	for _, schema := range db.Schemas {
+		for _, table := range schema.Tables {
+			if table.Name == "users" {
+				usersTable = table
+			} else if table.Name == "posts" {
+				postsTable = table
+			}
+		}
+	}
+
+	if usersTable == nil {
+		t.Fatal("Users table not found")
+	}
+	if postsTable == nil {
+		t.Fatal("Posts table not found")
+	}
+
+	// Test unique constraint naming: uq_table_column
+	if _, exists := usersTable.Constraints["uq_users_email"]; !exists {
+		t.Error("Expected unique constraint 'uq_users_email' not found")
+		t.Logf("Available constraints: %v", getKeys(usersTable.Constraints))
+	}
+
+	if _, exists := postsTable.Constraints["uq_posts_slug"]; !exists {
+		t.Error("Expected unique constraint 'uq_posts_slug' not found")
+		t.Logf("Available constraints: %v", getKeys(postsTable.Constraints))
+	}
+
+	// Test foreign key naming: fk_table_column
+	if _, exists := postsTable.Constraints["fk_posts_user_id"]; !exists {
+		t.Error("Expected foreign key 'fk_posts_user_id' not found")
+		t.Logf("Available constraints: %v", getKeys(postsTable.Constraints))
+	}
+
+	// Test unique index naming: uidx_table_columns
+	if _, exists := postsTable.Indexes["uidx_posts_slug"]; !exists {
+		t.Error("Expected unique index 'uidx_posts_slug' not found")
+		t.Logf("Available indexes: %v", getKeys(postsTable.Indexes))
+	}
+
+	// Test regular index naming: idx_table_columns
+	if _, exists := postsTable.Indexes["idx_posts_user_id_published"]; !exists {
+		t.Error("Expected index 'idx_posts_user_id_published' not found")
+		t.Logf("Available indexes: %v", getKeys(postsTable.Indexes))
+	}
+}
+
+func getKeys[V any](m map[string]V) []string {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
 func TestHasCommentedRefs(t *testing.T) {
 	// Test with the actual multifile test fixtures
 	tests := []struct {