[planner bugfix] add expressions to HAVING (vitessio#12668) (vitessio#12699)

* [planner bugfix] add expressions to HAVING

When a predicate contains aggregation, it should not
be added to the WHERE clause. It should go to the



* update test expecteations



---------

Signed-off-by: Andres Taylor <andres@planetscale.com>
Signed-off-by: Florent Poinsard <florent.poinsard@outlook.fr>
Co-authored-by: Andres Taylor <andres@planetscale.com>

Author: frouioui

go/vt/sqlparser/ast_funcs.go

@@ -991,10 +991,8 @@ func (node *Select) AddHaving(expr Expr) {
 		}
 		return
 	}
-	node.Having.Expr = &AndExpr{
-		Left:  node.Having.Expr,
-		Right: expr,
-	}
+	exprs := SplitAndExpression(nil, node.Having.Expr)
+	node.Having.Expr = AndExpressions(append(exprs, expr)...)
 }
 
 // AddGroupBy adds a grouping expression, unless it's already present

go/vt/sqlparser/ast_test.go

@@ -57,32 +57,22 @@ func TestSelect(t *testing.T) {
 	sel.AddWhere(expr)
 	buf := NewTrackedBuffer(nil)
 	sel.Where.Format(buf)
-	want := " where a = 1"
-	if buf.String() != want {
-		t.Errorf("where: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " where a = 1", buf.String())
 	sel.AddWhere(expr)
 	buf = NewTrackedBuffer(nil)
 	sel.Where.Format(buf)
-	want = " where a = 1"
-	if buf.String() != want {
-		t.Errorf("where: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " where a = 1", buf.String())
+
 	sel = &Select{}
 	sel.AddHaving(expr)
 	buf = NewTrackedBuffer(nil)
 	sel.Having.Format(buf)
-	want = " having a = 1"
-	if buf.String() != want {
-		t.Errorf("having: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " having a = 1", buf.String())
+
 	sel.AddHaving(expr)
 	buf = NewTrackedBuffer(nil)
 	sel.Having.Format(buf)
-	want = " having a = 1 and a = 1"
-	if buf.String() != want {
-		t.Errorf("having: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " having a = 1", buf.String())
 
 	tree, err = Parse("select * from t where a = 1 or b = 1")
 	require.NoError(t, err)
@@ -91,18 +81,14 @@ func TestSelect(t *testing.T) {
 	sel.AddWhere(expr)
 	buf = NewTrackedBuffer(nil)
 	sel.Where.Format(buf)
-	want = " where a = 1 or b = 1"
-	if buf.String() != want {
-		t.Errorf("where: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " where a = 1 or b = 1", buf.String())
+
 	sel = &Select{}
 	sel.AddHaving(expr)
 	buf = NewTrackedBuffer(nil)
 	sel.Having.Format(buf)
-	want = " having a = 1 or b = 1"
-	if buf.String() != want {
-		t.Errorf("having: %q, want %s", buf.String(), want)
-	}
+	assert.Equal(t, " having a = 1 or b = 1", buf.String())
+
 }
 
 func TestUpdate(t *testing.T) {

go/vt/vtgate/planbuilder/operator_to_query.go

@@ -89,7 +89,7 @@ func buildQuery(op abstract.PhysicalOperator, qb *queryBuilder) {
 		sel.Limit = opQuery.Limit
 		sel.OrderBy = opQuery.OrderBy
 		sel.GroupBy = opQuery.GroupBy
-		sel.Having = opQuery.Having
+		sel.Having = mergeHaving(sel.Having, opQuery.Having)
 		sel.SelectExprs = opQuery.SelectExprs
 		qb.addTableExpr(op.Alias, op.Alias, op.TableID(), &sqlparser.DerivedTable{
 			Select: sel,
@@ -161,12 +161,16 @@ func (qb *queryBuilder) addPredicate(expr sqlparser.Expr) {
 	}
 
 	sel := qb.sel.(*sqlparser.Select)
-	if sel.Where == nil {
-		sel.AddWhere(expr)
-		return
+	_, isSubQuery := expr.(*sqlparser.ExtractedSubquery)
+	var addPred func(sqlparser.Expr)
+
+	if sqlparser.ContainsAggregation(expr) && !isSubQuery {
+		addPred = sel.AddHaving
+	} else {
+		addPred = sel.AddWhere
 	}
 	for _, exp := range sqlparser.SplitAndExpression(nil, expr) {
-		sel.AddWhere(exp)
+		addPred(exp)
 	}
 }
 
@@ -288,3 +292,17 @@ func (ts *tableSorter) Less(i, j int) bool {
 func (ts *tableSorter) Swap(i, j int) {
 	ts.sel.From[i], ts.sel.From[j] = ts.sel.From[j], ts.sel.From[i]
 }
+
+func mergeHaving(h1, h2 *sqlparser.Where) *sqlparser.Where {
+	switch {
+	case h1 == nil && h2 == nil:
+		return nil
+	case h1 == nil:
+		return h2
+	case h2 == nil:
+		return h1
+	default:
+		h1.Expr = sqlparser.AndExpressions(h1.Expr, h2.Expr)
+		return h1
+	}
+}

go/vt/vtgate/planbuilder/testdata/aggr_cases.json

@@ -4996,5 +4996,42 @@
         "user.user"
       ]
     }
+  },
+  {
+    "comment": "when pushing predicates into derived tables, make sure to put them in HAVING when they contain aggregations",
+    "query": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as count from user_extra where localDate > :v1 group by user_id, flowId order by null) as t1 where count >= :v2",
+    "v3-plan": {
+      "QueryType": "SELECT",
+      "Original": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as count from user_extra where localDate > :v1 group by user_id, flowId order by null) as t1 where count >= :v2",
+      "Instructions": {
+        "OperatorType": "Route",
+        "Variant": "Scatter",
+        "Keyspace": {
+          "Name": "user",
+          "Sharded": true
+        },
+        "FieldQuery": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as `count` from user_extra where 1 != 1 group by user_id, flowId) as t1 where 1 != 1",
+        "Query": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as `count` from user_extra where localDate > :v1 group by user_id, flowId order by null) as t1 where `count` >= :v2",
+        "Table": "user_extra"
+      }
+    },
+    "gen4-plan": {
+      "QueryType": "SELECT",
+      "Original": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as count from user_extra where localDate > :v1 group by user_id, flowId order by null) as t1 where count >= :v2",
+      "Instructions": {
+        "OperatorType": "Route",
+        "Variant": "Scatter",
+        "Keyspace": {
+          "Name": "user",
+          "Sharded": true
+        },
+        "FieldQuery": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as `count` from user_extra where 1 != 1 group by user_id, flowId) as t1 where 1 != 1",
+        "Query": "select t1.portalId, t1.flowId from (select portalId, flowId, count(*) as `count` from user_extra where localDate > :v1 group by user_id, flowId having count(*) >= :v2 order by null) as t1",
+        "Table": "user_extra"
+      },
+      "TablesUsed": [
+        "user.user_extra"
+      ]
+    }
   }
 ]