Method walkSelectList

datasource/sqlite/sqlrewrite.go:90–134

Aggregations from the SELECT FROM ... WHERE

()

//    SELECT <select_list> FROM ... WHERE
//
func (m *rewrite) walkSelectList() error {

	m.result.Columns = m.sel.Columns

	for i := len(m.result.Columns) - 1; i >= 0; i-- {
		col := m.result.Columns[i]
		//u.Debugf("i=%d of %d  %v %#v ", i, len(m.sel.Columns), col.Key(), col)
		if col.Expr != nil {
			switch curNode := col.Expr.(type) {
			// case *expr.NumberNode:
			// 	return nil, value.NewNumberValue(curNode.Float64), nil
			// case *expr.BinaryNode:
			// 	return m.walkBinary(curNode)
			// case *expr.TriNode: // Between
			// 	return m.walkTri(curNode)
			// case *expr.UnaryNode:
			// 	return m.walkUnary(curNode)
			case *expr.FuncNode:
				// All Func Nodes are Aggregates?
				newNode, err := m.selectFunc(curNode)
				if err == nil {
					col.Expr = newNode
				} else if err != nil {
					u.Error(err)
					return err
				}
				//u.Debugf("esm: %v:%v", col.As, esm)
				//u.Debugf(curNode.String())
			// case *expr.ArrayNode:
			// 	return m.walkArrayNode(curNode)
			// case *expr.IdentityNode:
			// 	return nil, value.NewStringValue(curNode.Text), nil
			// case *expr.StringNode:
			// 	return nil, value.NewStringValue(curNode.Text), nil
			case *expr.IdentityNode:
				//u.Debugf("likely a projection, not agg T:%T  %v", curNode, curNode)
			default:
				u.Warnf("unrecognized not agg T:%T  %v", curNode, curNode)
				//panic("Unrecognized node type")
			}
		}

	}
	return nil
}

// Group By Clause:  Mongo is a little weird where they move the
// group by expressions INTO the aggregation clause: