diff --git a/sql/ast.go b/sql/ast.go
index c4f47a64..556ca62f 100644
--- a/sql/ast.go
+++ b/sql/ast.go
@@ -268,7 +268,7 @@ type DefineIndexStatement struct {
 	Name string   `cork:"name" codec:"name"`
 	What []string `cork:"-" codec:"-"`
 	Cols []string `cork:"cols" codec:"cols"`
-	Uniq bool     `cork:"unique" codec:"unique"`
+	Uniq bool     `cork:"uniq" codec:"uniq"`
 }
 
 // RemoveIndexStatement represents an SQL REMOVE INDEX statement.
@@ -317,18 +317,38 @@ type All struct{}
 // Asc represents the ASC expression.
 type Asc struct{}
 
+func (this Asc) MarshalText() (data []byte, err error) {
+	return []byte("~ASC~"), err
+}
+
 // Desc represents the DESC expression.
 type Desc struct{}
 
+func (this Desc) MarshalText() (data []byte, err error) {
+	return []byte("~DESC~"), err
+}
+
 // Null represents a null expression.
 type Null struct{}
 
+func (this Null) MarshalText() (data []byte, err error) {
+	return []byte("~NULL~"), err
+}
+
 // Void represents an expression which is not set.
 type Void struct{}
 
+func (this Void) MarshalText() (data []byte, err error) {
+	return []byte("~VOID~"), err
+}
+
 // Empty represents an expression which is null or "".
 type Empty struct{}
 
+func (this Empty) MarshalText() (data []byte, err error) {
+	return []byte("~EMPTY~"), err
+}
+
 // Field represents a SELECT AS clause.
 type Field struct {
 	Expr  Expr
@@ -386,6 +406,10 @@ func (this Ident) String() string {
 	return this.ID
 }
 
+func (this Ident) MarshalText() (data []byte, err error) {
+	return []byte("ID:" + this.ID), err
+}
+
 func NewIdent(ID string) *Ident {
 	return &Ident{ID}
 }
@@ -403,6 +427,10 @@ func (this Table) String() string {
 	return this.TB
 }
 
+func (this Table) MarshalText() (data []byte, err error) {
+	return []byte("TB:" + this.TB), err
+}
+
 func NewTable(TB string) *Table {
 	return &Table{TB}
 }
@@ -421,6 +449,10 @@ func (this Thing) String() string {
 	return fmt.Sprintf("@%s:%v", this.TB, this.ID)
 }
 
+func (this Thing) MarshalText() (data []byte, err error) {
+	return []byte(this.String()), err
+}
+
 func NewThing(TB string, ID interface{}) *Thing {
 	if str, ok := ID.(string); ok {
 		if cnv, err := strconv.ParseInt(str, 10, 64); err == nil {
diff --git a/sql/token.go b/sql/token.go
index c701cefe..08309166 100644
--- a/sql/token.go
+++ b/sql/token.go
@@ -418,6 +418,10 @@ func (tok Token) String() string {
 	return ""
 }
 
+func (tok Token) MarshalText() (data []byte, err error) {
+	return []byte(tok.String()), err
+}
+
 func (tok Token) isLiteral() bool { return tok > literalsBeg && tok < literalsEnd }
 
 func (tok Token) isKeyword() bool { return tok > keywordsBeg && tok < keywordsEnd }