parser, executor: support show/set session_states (#35263)

close #35259

executor/executor_test.go

@@ -6070,3 +6070,12 @@ func TestIsFastPlan(t *testing.T) {
 		require.Equal(t, ca.isFastPlan, ok)
 	}
 }
+
+func TestShowSessionStates(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustQuery("show session_states").Check(testkit.Rows())
+	tk.MustExec("set session_states 'x'")
+	tk.MustGetErrCode("set session_states 1", errno.ErrParse)
+}

executor/show.go

@@ -235,6 +235,8 @@ func (e *ShowExec) fetchAll(ctx context.Context) error {
 		return e.fetchShowPlacementForTable(ctx)
 	case ast.ShowPlacementForPartition:
 		return e.fetchShowPlacementForPartition(ctx)
+	case ast.ShowSessionStates:
+		return e.fetchShowSessionStates(ctx)
 	}
 	return nil
 }
@@ -1927,6 +1929,10 @@ func (e *ShowExec) fetchShowBuiltins() error {
 	return nil
 }
 
+func (e *ShowExec) fetchShowSessionStates(ctx context.Context) error {
+	return nil
+}
+
 // tryFillViewColumnType fill the columns type info of a view.
 // Because view's underlying table's column could change or recreate, so view's column type may change over time.
 // To avoid this situation we need to generate a logical plan and extract current column types from Schema.

executor/simple.go

@@ -151,6 +151,8 @@ func (e *SimpleExec) Next(ctx context.Context, req *chunk.Chunk) (err error) {
 		err = e.executeRenameUser(x)
 	case *ast.SetPwdStmt:
 		err = e.executeSetPwd(ctx, x)
+	case *ast.SetSessionStatesStmt:
+		err = e.executeSetSessionStates(ctx, x)
 	case *ast.KillStmt:
 		err = e.executeKillStmt(ctx, x)
 	case *ast.BinlogStmt:
@@ -1684,6 +1686,10 @@ func asyncDelayShutdown(p *os.Process, delay time.Duration) {
 	}
 }
 
+func (e *SimpleExec) executeSetSessionStates(ctx context.Context, s *ast.SetSessionStatesStmt) error {
+	return nil
+}
+
 func (e *SimpleExec) executeAdmin(s *ast.AdminStmt) error {
 	switch s.Tp {
 	case ast.AdminReloadStatistics:

parser/ast/dml.go

@@ -2674,6 +2674,7 @@ const (
 	ShowPlacementForTable
 	ShowPlacementForPartition
 	ShowPlacementLabels
+	ShowSessionStates
 )
 
 const (
@@ -3025,6 +3026,8 @@ func (n *ShowStmt) Restore(ctx *format.RestoreCtx) error {
 			ctx.WriteKeyWord("PLACEMENT")
 		case ShowPlacementLabels:
 			ctx.WriteKeyWord("PLACEMENT LABELS")
+		case ShowSessionStates:
+			ctx.WriteKeyWord("SESSION_STATES")
 		default:
 			return errors.New("Unknown ShowStmt type")
 		}

parser/ast/misc.go

@@ -46,6 +46,7 @@ var (
 	_ StmtNode = &SetRoleStmt{}
 	_ StmtNode = &SetDefaultRoleStmt{}
 	_ StmtNode = &SetStmt{}
+	_ StmtNode = &SetSessionStatesStmt{}
 	_ StmtNode = &UseStmt{}
 	_ StmtNode = &FlushStmt{}
 	_ StmtNode = &KillStmt{}
@@ -1055,6 +1056,28 @@ func (n *SetConfigStmt) Accept(v Visitor) (Node, bool) {
 	return v.Leave(n)
 }
 
+// SetSessionStatesStmt is a statement to restore session states.
+type SetSessionStatesStmt struct {
+	stmtNode
+
+	SessionStates string
+}
+
+func (n *SetSessionStatesStmt) Restore(ctx *format.RestoreCtx) error {
+	ctx.WriteKeyWord("SET SESSION_STATES ")
+	ctx.WriteString(n.SessionStates)
+	return nil
+}
+
+func (n *SetSessionStatesStmt) Accept(v Visitor) (Node, bool) {
+	newNode, skipChildren := v.Enter(n)
+	if skipChildren {
+		return v.Leave(newNode)
+	}
+	n = newNode.(*SetSessionStatesStmt)
+	return v.Leave(n)
+}
+
 /*
 // SetCharsetStmt is a statement to assign values to character and collation variables.
 // See https://dev.mysql.com/doc/refman/5.7/en/set-statement.html

parser/misc.go

@@ -632,6 +632,7 @@ var tokenMap = map[string]int{
 	"SERIAL":                   serial,
 	"SERIALIZABLE":             serializable,
 	"SESSION":                  session,
+	"SESSION_STATES":           sessionStates,
 	"SET":                      set,
 	"SETVAL":                   setval,
 	"SHARD_ROW_ID_BITS":        shardRowIDBits,