Merge pull request #1170 from influxdb/parse-select-star

Make influxql parse SELECT *

influxql/ast.go

@@ -47,6 +47,7 @@ func (_ *TimeLiteral) node()     {}
 func (_ *DurationLiteral) node() {}
 func (_ *BinaryExpr) node()      {}
 func (_ *ParenExpr) node()       {}
+func (_ *Wildcard) node()        {}
 
 // Query represents a collection of order statements.
 type Query struct {
@@ -85,6 +86,7 @@ func (_ *TimeLiteral) expr()     {}
 func (_ *DurationLiteral) expr() {}
 func (_ *BinaryExpr) expr()      {}
 func (_ *ParenExpr) expr()       {}
+func (_ *Wildcard) expr()        {}
 
 // Source represents a source of data for a statement.
 type Source interface {
@@ -234,6 +236,10 @@ type ParenExpr struct {
 	Expr Expr
 }
 
+// Wildcard represents a wild card expression.
+type Wildcard struct {
+}
+
 // Visitor can be called by Walk to traverse an AST hierarchy.
 // The Visit() function is called once per node.
 type Visitor interface {

influxql/parser.go

@@ -90,8 +90,6 @@ func (p *Parser) ParseStatement() (Statement, error) {
 func (p *Parser) parseSelectStatement() (*SelectStatement, error) {
 	stmt := &SelectStatement{}
 
-	// TODO: handle SELECT *
-
 	// Parse fields: "SELECT FIELD+".
 	fields, err := p.parseFields()
 	if err != nil {
@@ -264,6 +262,14 @@ func (p *Parser) parseDropContinuousQueryStatement() (*DropContinuousQueryStatem
 // parseFields parses a list of one or more fields.
 func (p *Parser) parseFields() (Fields, error) {
 	var fields Fields
+
+	// Check for "*" (i.e., "all fields")
+	if tok, _, _ := p.scanIgnoreWhitespace(); tok == MUL {
+		fields = append(fields, &Field{&Wildcard{}, ""})
+		return fields, nil
+	}
+	p.unscan()
+
 	for {
 		// Parse the field.
 		f, err := p.parseField()

influxql/parser_test.go

@@ -45,6 +45,17 @@ func TestParser_ParseStatement(t *testing.T) {
 		stmt influxql.Statement
 		err  string
 	}{
+		// SELECT * statement
+		{
+			s: `SELECT * FROM myseries`,
+			stmt: &influxql.SelectStatement{
+				Fields: influxql.Fields{
+					&influxql.Field{Expr: &influxql.Wildcard{}},
+				},
+				Source: &influxql.Series{Name: "myseries"},
+			},
+		},
+
 		// SELECT statement
 		{
 			s: `SELECT field1, field2 ,field3 AS field_x FROM myseries WHERE host = 'hosta.influxdb.org' GROUP BY 10h LIMIT 20 ORDER BY ASC;`,