[release-22.0] fix: remove database qualifier after building query in operator to sql (#18602)

go/test/endtoend/vtgate/queries/orderby/orderby_test.go

@@ -53,6 +53,15 @@ func TestSimpleOrderBy(t *testing.T) {
 	mcmp.AssertMatches(`SELECT id2 FROM t1 ORDER BY id2 ASC`, `[[INT64(5)] [INT64(6)] [INT64(7)] [INT64(8)] [INT64(9)] [INT64(10)]]`)
 }
 
+// TestQueryWithDBQualifier tests that we remove the db qualifier in the plan output that is sent down to the database.
+func TestQueryWithDBQualifier(t *testing.T) {
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into t1(id1, id2) values (0,10),(1,9),(2,8),(3,7),(4,6),(5,5)")
+	mcmp.Exec(`SELECT ks_orderby.t1.id1, ks_orderby.t1.id2 FROM ks_orderby.t1 ORDER BY ks_orderby.t1.id2 ASC, ks_orderby.t1.id1 desc`)
+}
+
 func TestOrderBy(t *testing.T) {
 	mcmp, closer := start(t)
 	defer closer()

go/vt/vtgate/planbuilder/operators/SQL_builder.go

@@ -55,6 +55,7 @@ func ToSQL(ctx *plancontext.PlanningContext, op Operator) (_ sqlparser.Statement
 	if ctx.SemTable != nil {
 		q.sortTables()
 	}
+	sqlparser.RemoveKeyspaceIgnoreSysSchema(q.stmt)
 	return q.stmt, q.dmlOperator, nil
 }
 
@@ -395,15 +396,6 @@ func (ts *tableSorter) Swap(i, j int) {
 	ts.sel.From[i], ts.sel.From[j] = ts.sel.From[j], ts.sel.From[i]
 }
 
-func removeKeyspaceFromSelectExpr(expr sqlparser.SelectExpr) {
-	switch expr := expr.(type) {
-	case *sqlparser.AliasedExpr:
-		sqlparser.RemoveKeyspaceInCol(expr.Expr)
-	case *sqlparser.StarExpr:
-		expr.TableName.Qualifier = sqlparser.NewIdentifierCS("")
-	}
-}
-
 func stripDownQuery(from, to sqlparser.TableStatement) {
 	switch node := from.(type) {
 	case *sqlparser.Select:
@@ -418,9 +410,6 @@ func stripDownQuery(from, to sqlparser.TableStatement) {
 		toNode.Comments = node.Comments
 		toNode.Limit = node.Limit
 		toNode.SelectExprs = node.SelectExprs
-		for _, expr := range toNode.SelectExprs.Exprs {
-			removeKeyspaceFromSelectExpr(expr)
-		}
 	case *sqlparser.Union:
 		toNode, ok := to.(*sqlparser.Union)
 		if !ok {
@@ -666,8 +655,6 @@ func buildFilter(op *Filter, qb *queryBuilder) {
 func buildDerived(op *Horizon, qb *queryBuilder) {
 	buildQuery(op.Source, qb)
 
-	sqlparser.RemoveKeyspaceInCol(op.Query)
-
 	stmt := qb.stmt
 	qb.stmt = nil
 	switch sel := stmt.(type) {
@@ -718,7 +705,6 @@ func buildDerivedSelect(op *Horizon, qb *queryBuilder, sel *sqlparser.Select) {
 func buildHorizon(op *Horizon, qb *queryBuilder) {
 	buildQuery(op.Source, qb)
 	stripDownQuery(op.Query, qb.asSelectStatement())
-	sqlparser.RemoveKeyspaceInCol(qb.stmt)
 }
 
 func buildRecursiveCTE(op *RecurseCTE, qb *queryBuilder) {

go/vt/vtgate/planbuilder/operators/route.go

@@ -567,8 +567,6 @@ func createProjection(ctx *plancontext.PlanningContext, src Operator, derivedNam
 }
 
 func (r *Route) AddColumn(ctx *plancontext.PlanningContext, reuse bool, gb bool, expr *sqlparser.AliasedExpr) int {
-	removeKeyspaceFromSelectExpr(expr)
-
 	if reuse {
 		offset := r.FindCol(ctx, expr.Expr, true)
 		if offset != -1 {

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

@@ -5074,5 +5074,50 @@
         "user.user"
       ]
     }
+  },
+  {
+    "comment": "order by and project pushed under route having database qualifier - it should be removed in final query",
+    "query": "select user.user.col from user.user order by user.user.id",
+    "plan": {
+      "Type": "Scatter",
+      "QueryType": "SELECT",
+      "Original": "select user.user.col from user.user order by user.user.id",
+      "Instructions": {
+        "OperatorType": "Route",
+        "Variant": "Scatter",
+        "Keyspace": {
+          "Name": "user",
+          "Sharded": true
+        },
+        "FieldQuery": "select `user`.col, `user`.id, weight_string(`user`.id) from `user` where 1 != 1",
+        "OrderBy": "(1|2) ASC",
+        "Query": "select `user`.col, `user`.id, weight_string(`user`.id) from `user` order by `user`.id asc",
+        "ResultColumns": 1,
+        "Table": "`user`"
+      },
+      "TablesUsed": [
+        "user.user"
+      ]
+    }
+  },
+  {
+    "comment": "order by and project pushed under route having information_schema database qualifier - it should not be removed in final query",
+    "query": "select information_schema.table.col from information_schema.table order by information_schema.table.name",
+    "plan": {
+      "Type": "Passthrough",
+      "QueryType": "SELECT",
+      "Original": "select information_schema.table.col from information_schema.table order by information_schema.table.name",
+      "Instructions": {
+        "OperatorType": "Route",
+        "Variant": "DBA",
+        "Keyspace": {
+          "Name": "main",
+          "Sharded": false
+        },
+        "FieldQuery": "select information_schema.`table`.col from information_schema.`table` where 1 != 1",
+        "Query": "select information_schema.`table`.col from information_schema.`table` order by information_schema.`table`.`name` asc",
+        "Table": "information_schema.`table`"
+      }
+    }
   }
 ]