Merge pull request #6374 from influxdata/js-6296-rename-time-field

Allow the implicit time field to be renamed

CHANGELOG.md

@@ -20,6 +20,7 @@
 - [#6287](https://github.com/influxdata/influxdb/issues/6287): Fix data race in Influx Client.
 - [#6252](https://github.com/influxdata/influxdb/pull/6252): Remove TSDB listener accept message @simnv
 - [#6202](https://github.com/influxdata/influxdb/pull/6202): Check default SHARD DURATION when recreating the same database.
+- [#6296](https://github.com/influxdata/influxdb/issues/6296): Allow the implicit time field to be renamed again.
 
 ## v0.12.0 [2016-04-05]
 ### Release Notes

influxql/ast.go

@@ -903,6 +903,9 @@ type SelectStatement struct {
 	// The value to fill empty aggregate buckets with, if any
 	FillValue interface{}
 
+	// Renames the implicit time field name.
+	TimeAlias string
+
 	// Removes the "time" column from the output.
 	OmitTime bool
 
@@ -968,6 +971,14 @@ func (s *SelectStatement) TimeAscending() bool {
 	return len(s.SortFields) == 0 || s.SortFields[0].Ascending
 }
 
+// TimeFieldName returns the name of the time field.
+func (s *SelectStatement) TimeFieldName() string {
+	if s.TimeAlias != "" {
+		return s.TimeAlias
+	}
+	return "time"
+}
+
 // Clone returns a deep copy of the statement.
 func (s *SelectStatement) Clone() *SelectStatement {
 	clone := &SelectStatement{
@@ -1133,6 +1144,7 @@ func (s *SelectStatement) RewriteTimeFields() {
 		switch expr := s.Fields[i].Expr.(type) {
 		case *VarRef:
 			if expr.Val == "time" {
+				s.TimeAlias = s.Fields[i].Alias
 				s.Fields = append(s.Fields[:i], s.Fields[i+1:]...)
 			}
 		}
@@ -1169,7 +1181,7 @@ func (s *SelectStatement) ColumnNames() []string {
 	columnNames := make([]string, len(columnFields)+offset)
 	if !s.OmitTime {
 		// Add the implicit time if requested.
-		columnNames[0] = "time"
+		columnNames[0] = s.TimeFieldName()
 	}
 
 	// Keep track of the encountered column names.

influxql/ast_test.go

@@ -447,6 +447,56 @@ func TestSelectStatement_RewriteWildcards(t *testing.T) {
 	}
 }
 
+// Test SELECT statement time field rewrite.
+func TestSelectStatement_RewriteTimeFields(t *testing.T) {
+	var tests = []struct {
+		s    string
+		stmt influxql.Statement
+	}{
+		{
+			s: `SELECT time, field1 FROM cpu`,
+			stmt: &influxql.SelectStatement{
+				IsRawQuery: true,
+				Fields: []*influxql.Field{
+					{Expr: &influxql.VarRef{Val: "field1"}},
+				},
+				Sources: []influxql.Source{
+					&influxql.Measurement{Name: "cpu"},
+				},
+			},
+		},
+		{
+			s: `SELECT time AS timestamp, field1 FROM cpu`,
+			stmt: &influxql.SelectStatement{
+				IsRawQuery: true,
+				Fields: []*influxql.Field{
+					{Expr: &influxql.VarRef{Val: "field1"}},
+				},
+				Sources: []influxql.Source{
+					&influxql.Measurement{Name: "cpu"},
+				},
+				TimeAlias: "timestamp",
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		// Parse statement.
+		stmt, err := influxql.NewParser(strings.NewReader(tt.s)).ParseStatement()
+		if err != nil {
+			t.Fatalf("invalid statement: %q: %s", tt.s, err)
+		}
+
+		// Rewrite statement.
+		stmt.(*influxql.SelectStatement).RewriteTimeFields()
+		if !reflect.DeepEqual(tt.stmt, stmt) {
+			t.Logf("\n# %s\nexp=%s\ngot=%s\n", tt.s, mustMarshalJSON(tt.stmt), mustMarshalJSON(stmt))
+			t.Logf("\nSQL exp=%s\nSQL got=%s\n", tt.stmt.String(), stmt.String())
+			t.Errorf("%d. %q\n\nstmt mismatch:\n\nexp=%#v\n\ngot=%#v\n\n", i, tt.s, tt.stmt, stmt)
+		}
+	}
+}
+
 // Ensure that the IsRawQuery flag gets set properly
 func TestSelectStatement_IsRawQuerySet(t *testing.T) {
 	var tests = []struct {
@@ -1248,6 +1298,15 @@ func TestSelect_ColumnNames(t *testing.T) {
 			},
 			columns: []string{"time", "value_1", "value", "value_2"},
 		},
+		{
+			stmt: &influxql.SelectStatement{
+				Fields: influxql.Fields([]*influxql.Field{
+					{Expr: &influxql.VarRef{Val: "value"}},
+				}),
+				TimeAlias: "timestamp",
+			},
+			columns: []string{"timestamp", "value"},
+		},
 	} {
 		columns := tt.stmt.ColumnNames()
 		if !reflect.DeepEqual(columns, tt.columns) {