Cloning files from https://github.com/dropbox/godropbox/tree/master/database

sqlbuilder/types.go

@@ -0,0 +1,79 @@
+package sqlbuilder
+
+import (
+	"bytes"
+)
+
+type Clause interface {
+	SerializeSql(out *bytes.Buffer) error
+}
+
+// A clause that can be used in order by
+type OrderByClause interface {
+	Clause
+	isOrderByClauseInterface
+}
+
+// An expression
+type Expression interface {
+	Clause
+	isExpressionInterface
+}
+
+type BoolExpression interface {
+	Clause
+	isBoolExpressionInterface
+}
+
+// A clause that is selectable.
+type Projection interface {
+	Clause
+	isProjectionInterface
+	SerializeSqlForColumnList(out *bytes.Buffer) error
+}
+
+//
+// Boiler plates ...
+//
+
+type isOrderByClauseInterface interface {
+	isOrderByClauseType()
+}
+
+type isOrderByClause struct {
+}
+
+func (o *isOrderByClause) isOrderByClauseType() {
+}
+
+type isExpressionInterface interface {
+	isExpressionType()
+}
+
+type isExpression struct {
+	isOrderByClause // can always use expression in order by.
+}
+
+func (e *isExpression) isExpressionType() {
+}
+
+type isBoolExpressionInterface interface {
+	isExpressionInterface
+	isBoolExpressionType()
+}
+
+type isBoolExpression struct {
+}
+
+func (e *isBoolExpression) isBoolExpressionType() {
+}
+
+type isProjectionInterface interface {
+	isProjectionType()
+}
+
+type isProjection struct {
+}
+
+func (p *isProjection) isProjectionType() {
+}