x/sqbuilder: Make the Marker upgradable to QuerySegment

x/sqlbuilder/predicate_clause.go

@@ -160,8 +160,12 @@ func (svpcw *staticValuePredicateClauseWrapper) WriteTo(w QueryWriter, _ map[str
 	return svpcw.svpc.WriteTo(w)
 }
 
-type PredicateClause interface {
+type QuerySegment interface {
 	WriteTo(QueryWriter, map[string]interface{}) error
+}
+
+type PredicateClause interface {
+	QuerySegment
 	Clone() PredicateClause
 }
 

x/sqlbuilder/select_statement.go

@@ -42,6 +42,15 @@ func (ss SelectStatement) Clone() SelectStatement {
 	}
 }
 
+func writeSelectClause(c Marker, qw *queryWriter, vs map[string]interface{}) error {
+	if qs, ok := c.(QuerySegment); ok {
+		return qs.WriteTo(qw, vs)
+	}
+
+	qw.WriteString(c.ToSQL())
+	return nil
+}
+
 func (ss SelectStatement) buildQuery(vs map[string]interface{}) (string, []interface{}, []string, error) {
 	var (
 		qw       queryWriter
@@ -55,7 +64,9 @@ func (ss SelectStatement) buildQuery(vs map[string]interface{}) (string, []inter
 	qw.WriteString("SELECT ")
 
 	for i, c := range ss.SelectClauses {
-		qw.WriteString(c.ToSQL())
+		if err := writeSelectClause(c, &qw, vs); err != nil {
+			return "", nil, nil, err
+		}
 
 		if i < len(ss.SelectClauses)-1 {
 			qw.WriteString(", ")

x/sqlbuilder/update_statement.go

@@ -1,6 +1,9 @@
 package sqlbuilder
 
-import "fmt"
+import (
+	"fmt"
+	"io"
+)
 
 type UpdateStatement struct {
 	Table string
@@ -17,6 +20,22 @@ func (us UpdateStatement) Clone() UpdateStatement {
 	}
 }
 
+func writeUpdateClause(f Marker, qw *queryWriter, vs map[string]interface{}) error {
+	if qs, ok := f.(QuerySegment); ok {
+		return qs.WriteTo(qw, vs)
+	}
+
+	k := f.Binding()
+	v, ok := vs[k]
+
+	if !ok {
+		return ErrMissingKey{Key: k}
+	}
+
+	_, err := io.WriteString(qw, qw.RedeemVariable(v))
+	return err
+}
+
 func (us UpdateStatement) buildQuery(vs map[string]interface{}) (string, []interface{}, error) {
 	var qw queryWriter
 
@@ -27,15 +46,12 @@ func (us UpdateStatement) buildQuery(vs map[string]interface{}) (string, []inter
 	fmt.Fprintf(&qw, "UPDATE %s SET ", us.Table)
 
 	for i, f := range us.Fields {
-		k := f.Binding()
-		v, ok := vs[k]
+		fmt.Fprintf(&qw, "%s = ", columnName(f))
 
-		if !ok {
-			return "", nil, ErrMissingKey{Key: k}
+		if err := writeUpdateClause(f, &qw, vs); err != nil {
+			return "", nil, err
 		}
 
-		fmt.Fprintf(&qw, "%s = %s", columnName(f), qw.RedeemVariable(v))
-
 		if i < len(us.Fields)-1 {
 			qw.WriteString(", ")
 		}