feat(domains): ✨ add domain support for DrawDB integration

- Introduce Domain and DomainTable models for logical grouping of tables.
- Implement export and import functionality for domains in DrawDB format.
- Update template execution modes to include domain processing.
- Enhance documentation for domain features and usage.

pkg/models/models.go

@@ -21,6 +21,7 @@ type Database struct {
 	Name            string       `json:"name" yaml:"name"`
 	Description     string       `json:"description,omitempty" yaml:"description,omitempty" xml:"description,omitempty"`
 	Schemas         []*Schema    `json:"schemas" yaml:"schemas" xml:"schemas"`
+	Domains         []*Domain    `json:"domains,omitempty" yaml:"domains,omitempty" xml:"domains,omitempty"`
 	Comment         string       `json:"comment,omitempty" yaml:"comment,omitempty" xml:"comment,omitempty"`
 	DatabaseType    DatabaseType `json:"database_type,omitempty" yaml:"database_type,omitempty" xml:"database_type,omitempty"`
 	DatabaseVersion string       `json:"database_version,omitempty" yaml:"database_version,omitempty" xml:"database_version,omitempty"`
@@ -32,6 +33,32 @@ func (d *Database) SQLName() string {
 	return strings.ToLower(d.Name)
 }
 
+// Domain represents a logical business domain grouping multiple tables from potentially different schemas.
+// Domains allow for organizing database tables by functional areas (e.g., authentication, user data, financial).
+type Domain struct {
+	Name        string         `json:"name" yaml:"name" xml:"name"`
+	Description string         `json:"description,omitempty" yaml:"description,omitempty" xml:"description,omitempty"`
+	Tables      []*DomainTable `json:"tables" yaml:"tables" xml:"tables"`
+	Comment     string         `json:"comment,omitempty" yaml:"comment,omitempty" xml:"comment,omitempty"`
+	Metadata    map[string]any `json:"metadata,omitempty" yaml:"metadata,omitempty" xml:"-"`
+	Sequence    uint           `json:"sequence,omitempty" yaml:"sequence,omitempty" xml:"sequence,omitempty"`
+}
+
+// SQLName returns the domain name in lowercase for SQL compatibility.
+func (d *Domain) SQLName() string {
+	return strings.ToLower(d.Name)
+}
+
+// DomainTable represents a reference to a specific table within a domain.
+// It identifies the table by name and schema, allowing a single domain to include
+// tables from multiple schemas.
+type DomainTable struct {
+	TableName  string `json:"table_name" yaml:"table_name" xml:"table_name"`
+	SchemaName string `json:"schema_name" yaml:"schema_name" xml:"schema_name"`
+	Sequence   uint   `json:"sequence,omitempty" yaml:"sequence,omitempty" xml:"sequence,omitempty"`
+	RefTable   *Table `json:"-" yaml:"-" xml:"-"` // Excluded to prevent circular references
+}
+
 // Schema represents a database schema, which is a logical grouping of database objects
 // such as tables, views, sequences, and relationships within a database.
 type Schema struct {
@@ -295,6 +322,7 @@ func InitDatabase(name string) *Database {
 	return &Database{
 		Name:    name,
 		Schemas: make([]*Schema, 0),
+		Domains: make([]*Domain, 0),
 	}
 }
 
@@ -402,3 +430,20 @@ func InitSequence(name, schema string) *Sequence {
 		StartValue:  1,
 	}
 }
+
+// InitDomain initializes a new Domain with empty slices and maps
+func InitDomain(name string) *Domain {
+	return &Domain{
+		Name:     name,
+		Tables:   make([]*DomainTable, 0),
+		Metadata: make(map[string]any),
+	}
+}
+
+// InitDomainTable initializes a new DomainTable reference
+func InitDomainTable(tableName, schemaName string) *DomainTable {
+	return &DomainTable{
+		TableName:  tableName,
+		SchemaName: schemaName,
+	}
+}