error on group by

Author: jakeheft

bttest/sql_parse.go

@@ -11,7 +11,8 @@ import (
 // restricted GoogleSQL subset using SPLIT(_key, sep)[SAFE_OFFSET(n)] AS alias
 // to extract row key components.
 var (
-	reFrom = regexp.MustCompile("(?i)FROM\\s+`([^`]+)`")
+	reFrom    = regexp.MustCompile("(?i)FROM\\s+`([^`]+)`")
+	reGroupBy = regexp.MustCompile(`(?i)\bGROUP\s+BY\b`)
 
 	// Matches: SPLIT(_key, '#')[SAFE_OFFSET(3)] AS alias
 	reSplitOffset = regexp.MustCompile(
@@ -38,6 +39,10 @@ var (
 //
 // The ORDER BY clause determines the CMV key component ordering.
 func ParseCMVConfigFromSQL(viewID, query string) (*CMVConfig, error) {
+	if reGroupBy.MatchString(query) {
+		return nil, fmt.Errorf("GROUP BY (aggregation) queries are not supported; only ORDER BY (key re-mapping) CMVs are emulated")
+	}
+
 	cfg := &CMVConfig{ViewID: viewID}
 
 	sourceTable, err := parseSourceTable(query)

bttest/sql_parse_test.go

@@ -99,62 +99,12 @@ ORDER BY b, a`,
 			},
 		},
 		{
-			// https://github.com/googleapis/google-cloud-go/blob/main/bigtable/integration_test.go#L4831C36-L4831C101
-			query: "SELECT _key, count(fam1['col1']) as count FROM `t1` GROUP BY _key",
-			expectCfg: &CMVConfig{
-				SourceTable:     "t1",
-				IncludeFamilies: []string{"fam1"},
-			},
-		},
-		{
-			// https://docs.cloud.google.com/bigtable/docs/continuous-materialized-view-queries#aggregated-data
-			query: `SELECT
-  fam["baz"] AS baz,
-  SUM(fam["foo"]) AS sum_foo,
-  SUM(fam["bar"]) AS sum_bar
-FROM
-  ` + "`TABLE`" + `
-GROUP BY
-  baz`,
-			expectCfg: &CMVConfig{
-				SourceTable: "TABLE",
-			},
-		},
-		{
-			// https://docs.cloud.google.com/bigtable/docs/continuous-materialized-view-queries#select-statement
-			query: `SELECT
-  myfamily["node"] AS node,
-  myfamily["type"] AS type,
-  COUNT(clicks) AS clicks_per_key
-FROM
-  ` + "`mytable`" + `
-GROUP BY
-  node,
-  type`,
-			expectCfg: &CMVConfig{
-				SourceTable: "mytable",
-			},
+			// GROUP BY (aggregation) queries are not supported — the emulator only handles
+			// ORDER BY (key re-mapping) CMVs. Aggregation requires maintaining running state
+			// across writes, which is a fundamentally different execution model.
+			query:     "SELECT _key, count(fam1['col1']) as count FROM `t1` GROUP BY _key",
+			expectErr: "GROUP BY",
 		},
-		{
-			// https://docs.cloud.google.com/bigtable/docs/continuous-materialized-view-queries#timestamps
-			query: `SELECT
-  _key,
-  TIMESTAMP_TRUNC(_timestamp, DAY) AS _timestamp,
-  SUM(sum_family["sum_column"]) AS sum_column,
-  SUM(sum_family["foo"]) AS second_sum_column
-FROM
-  UNPACK(
-  SELECT
-    *
-  FROM
-    my_table(with_history => TRUE))
-GROUP BY
-  1,
-  2`,
-			expectCfg: &CMVConfig{
-				SourceTable: "my_table",
-			},
-		}
 	}
 
 	for i, tc := range tests {