variable: add support for identity (pingcap#28449)

HelloMensa · Sep 28, 2021 · b50474c · b50474c
1 parent fd73942
commit b50474c
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Showing 4 changed files with 31 additions and 1 deletion.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -10338,3 +10338,17 @@ func (s *testIntegrationSuite) TestLastInsertId(c *C) {
 	tk.MustExec(`INSERT INTO lastinsertid VALUES (NULL);`)
 	tk.MustQuery("SELECT @@last_insert_id, LAST_INSERT_ID()").Check(testkit.Rows("3 3"))
 }
+
+func (s *testIntegrationSuite) TestIdentity(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test;`)
+	tk.MustExec(`drop table if exists identity;`)
+	tk.MustExec(`create table identity (id int not null primary key auto_increment);`)
+	tk.MustQuery("SELECT @@identity;").Check(testkit.Rows("0"))
+	tk.MustExec(`INSERT INTO identity VALUES (NULL);`)
+	tk.MustQuery("SELECT @@identity, LAST_INSERT_ID()").Check(testkit.Rows("1 1"))
+	tk.MustExec(`INSERT INTO identity VALUES (NULL);`)
+	tk.MustQuery("SELECT @@identity, LAST_INSERT_ID()").Check(testkit.Rows("2 2"))
+	tk.MustExec(`INSERT INTO identity VALUES (NULL);`)
+	tk.MustQuery("SELECT @@identity, LAST_INSERT_ID()").Check(testkit.Rows("3 3"))
+}
diff --git a/sessionctx/variable/noop.go b/sessionctx/variable/noop.go
@@ -485,7 +485,6 @@ var noopSysVars = []*SysVar{
 	{Scope: ScopeGlobal, Name: AvoidTemporalUpgrade, Value: Off, Type: TypeBool},
 	{Scope: ScopeGlobal, Name: "key_cache_age_threshold", Value: "300"},
 	{Scope: ScopeGlobal, Name: InnodbStatusOutput, Value: Off, Type: TypeBool, AutoConvertNegativeBool: true},
-	{Scope: ScopeSession, Name: "identity", Value: ""},
 	{Scope: ScopeGlobal | ScopeSession, Name: "min_examined_row_limit", Value: "0"},
 	{Scope: ScopeGlobal, Name: "sync_frm", Type: TypeBool, Value: On},
 	{Scope: ScopeGlobal, Name: "innodb_online_alter_log_max_size", Value: "134217728"},

diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
@@ -807,6 +807,9 @@ var defaultSysVars = []*SysVar{
 	{Scope: ScopeSession, Name: LastInsertID, Value: "", skipInit: true, GetSession: func(s *SessionVars) (string, error) {
 		return strconv.FormatUint(s.StmtCtx.PrevLastInsertID, 10), nil
 	}},
+	{Scope: ScopeSession, Name: Identity, Value: "", skipInit: true, GetSession: func(s *SessionVars) (string, error) {
+		return strconv.FormatUint(s.StmtCtx.PrevLastInsertID, 10), nil
+	}},
 	{Scope: ScopeNone, Name: "have_ssl", Value: "DISABLED"},
 	{Scope: ScopeNone, Name: "have_openssl", Value: "DISABLED"},
 	{Scope: ScopeNone, Name: "ssl_ca", Value: ""},
@@ -2136,6 +2139,8 @@ const (
 	DefaultAuthPlugin = "default_authentication_plugin"
 	// LastInsertID is the name of 'last_insert_id' system variable.
 	LastInsertID = "last_insert_id"
+	// Identity is the name of 'identity' system variable.
+	Identity = "identity"
 )
 
 // GlobalVarAccessor is the interface for accessing global scope system and status variables.

diff --git a/sessionctx/variable/sysvar_test.go b/sessionctx/variable/sysvar_test.go
@@ -734,3 +734,15 @@ func TestLastInsertID(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, val, "21")
 }
+
+func TestIdentity(t *testing.T) {
+	vars := NewSessionVars()
+	val, err := GetSessionOrGlobalSystemVar(vars, Identity)
+	require.NoError(t, err)
+	require.Equal(t, val, "0")
+
+	vars.StmtCtx.PrevLastInsertID = 21
+	val, err = GetSessionOrGlobalSystemVar(vars, Identity)
+	require.NoError(t, err)
+	require.Equal(t, val, "21")
+}