Add SQLBuilder support for SQLite databases.

sqlite/set_statement.go

@@ -0,0 +1,99 @@
+package sqlite
+
+import "github.com/go-jet/jet/v2/internal/jet"
+
+// UNION effectively appends the result of sub-queries(select statements) into single query.
+// It eliminates duplicate rows from its result.
+func UNION(lhs, rhs jet.SerializerStatement, selects ...jet.SerializerStatement) setStatement {
+	return newSetStatementImpl(union, false, toSelectList(lhs, rhs, selects...))
+}
+
+// UNION_ALL effectively appends the result of sub-queries(select statements) into single query.
+// It does not eliminates duplicate rows from its result.
+func UNION_ALL(lhs, rhs jet.SerializerStatement, selects ...jet.SerializerStatement) setStatement {
+	return newSetStatementImpl(union, true, toSelectList(lhs, rhs, selects...))
+}
+
+type setStatement interface {
+	setOperators
+
+	ORDER_BY(orderByClauses ...OrderByClause) setStatement
+
+	LIMIT(limit int64) setStatement
+	OFFSET(offset int64) setStatement
+
+	AsTable(alias string) SelectTable
+}
+
+type setOperators interface {
+	jet.Statement
+	jet.HasProjections
+	jet.Expression
+
+	UNION(rhs SelectStatement) setStatement
+	UNION_ALL(rhs SelectStatement) setStatement
+}
+
+type setOperatorsImpl struct {
+	parent setOperators
+}
+
+func (s *setOperatorsImpl) UNION(rhs SelectStatement) setStatement {
+	return UNION(s.parent, rhs)
+}
+
+func (s *setOperatorsImpl) UNION_ALL(rhs SelectStatement) setStatement {
+	return UNION_ALL(s.parent, rhs)
+}
+
+type setStatementImpl struct {
+	jet.ExpressionStatement
+
+	setOperatorsImpl
+
+	setOperator jet.ClauseSetStmtOperator
+}
+
+func newSetStatementImpl(operator string, all bool, selects []jet.SerializerStatement) setStatement {
+	newSetStatement := &setStatementImpl{}
+	newSetStatement.ExpressionStatement = jet.NewExpressionStatementImpl(Dialect, jet.SetStatementType, newSetStatement,
+		&newSetStatement.setOperator)
+
+	newSetStatement.setOperator.Operator = operator
+	newSetStatement.setOperator.All = all
+	newSetStatement.setOperator.Selects = selects
+	newSetStatement.setOperator.Limit.Count = -1
+	newSetStatement.setOperator.Offset.Count = -1
+	newSetStatement.setOperator.SkipSelectWrap = true
+
+	newSetStatement.setOperatorsImpl.parent = newSetStatement
+
+	return newSetStatement
+}
+
+func (s *setStatementImpl) ORDER_BY(orderByClauses ...OrderByClause) setStatement {
+	s.setOperator.OrderBy.List = orderByClauses
+	return s
+}
+
+func (s *setStatementImpl) LIMIT(limit int64) setStatement {
+	s.setOperator.Limit.Count = limit
+	return s
+}
+
+func (s *setStatementImpl) OFFSET(offset int64) setStatement {
+	s.setOperator.Offset.Count = offset
+	return s
+}
+
+func (s *setStatementImpl) AsTable(alias string) SelectTable {
+	return newSelectTable(s, alias)
+}
+
+const (
+	union = "UNION"
+)
+
+func toSelectList(lhs, rhs jet.SerializerStatement, selects ...jet.SerializerStatement) []jet.SerializerStatement {
+	return append([]jet.SerializerStatement{lhs, rhs}, selects...)
+}