implement stddev_pop(), stddev_samp(), var_pop(), var_samp(), and aliases

enginetest/queries/script_queries.go

@@ -7887,6 +7887,226 @@ where
 			},
 		},
 	},
+	{
+		Name:    "std, stdev, stddev_pop, variance, var_pop, var_samp tests",
+		Dialect: "mysql",
+		SetUpScript: []string{
+			"create table t (i int);",
+			"create table tt (i int, j int);",
+			"insert into tt values (0, 1), (0, 2), (0, 3);",
+			"insert into tt values (1, 123), (1, 456), (1, 789);",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: "select std(i), stddev(i), stddev_pop(i), stddev_samp(i) from t;",
+				Expected: []sql.Row{
+					{nil, nil, nil, nil},
+				},
+			},
+			{
+				Query: "select variance(i), var_pop(i), var_samp(i) from t;",
+				Expected: []sql.Row{
+					{nil, nil, nil},
+				},
+			},
+			{
+				Query: "insert into t values (1);",
+				Expected: []sql.Row{
+					{types.NewOkResult(1)},
+				},
+			},
+			{
+				Query: "select std(i), stddev(i), stddev_pop(i), stddev_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.0, 0.0, 0.0, nil},
+				},
+			},
+			{
+				Query: "select variance(i), var_pop(i), var_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.0, 0.0, nil},
+				},
+			},
+			{
+				Query: "insert into t values (2);",
+				Expected: []sql.Row{
+					{types.NewOkResult(1)},
+				},
+			},
+			{
+				Query: "select std(i), stddev(i), stddev_pop(i), stddev_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.5, 0.5, 0.5, 0.7071067811865476},
+				},
+			},
+			{
+				Query: "select variance(i), var_pop(i), var_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.25, 0.25, 0.5},
+				},
+			},
+			{
+				Query: "insert into t values (3);",
+				Expected: []sql.Row{
+					{types.NewOkResult(1)},
+				},
+			},
+			{
+				Query: "select std(i), stddev(i), stddev_pop(i), stddev_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.816496580927726, 0.816496580927726, 0.816496580927726, 1.0},
+				},
+			},
+			{
+				Query: "select variance(i), var_pop(i), var_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.6666666666666666, 0.6666666666666666, 1.0},
+				},
+			},
+			{
+				Query: "insert into t values (null), (null);",
+				Expected: []sql.Row{
+					{types.NewOkResult(2)},
+				},
+			},
+			{
+				Query: "select std(i), stddev(i), stddev_pop(i), stddev_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.816496580927726, 0.816496580927726, 0.816496580927726, 1.0},
+				},
+			},
+			{
+				Query: "select variance(i), var_pop(i), var_samp(i) from t;",
+				Expected: []sql.Row{
+					{0.6666666666666666, 0.6666666666666666, 1.0},
+				},
+			},
+			{
+				Query: "select i, std(j), stddev_samp(j) from tt group by i;",
+				Expected: []sql.Row{
+					{0, 0.816496580927726, 1.0},
+					{1, 271.89336144893275, 333.0},
+				},
+			},
+			{
+				Query: "select i, variance(i), var_samp(i) from tt group by i;",
+				Expected: []sql.Row{
+					{0, 0.0, 0.0},
+					{1, 0.0, 0.0},
+				},
+			},
+			{
+				Query: "select std(i) over(), std(j) over(), stddev_samp(j) over() from tt order by i;",
+				Expected: []sql.Row{
+					{0.5, 297.47660972475353, 325.86929895281634},
+					{0.5, 297.47660972475353, 325.86929895281634},
+					{0.5, 297.47660972475353, 325.86929895281634},
+					{0.5, 297.47660972475353, 325.86929895281634},
+					{0.5, 297.47660972475353, 325.86929895281634},
+					{0.5, 297.47660972475353, 325.86929895281634},
+				},
+			},
+			{
+				Query: "select i, std(j) over(partition by i), stddev_samp(j) over(partition by i) from tt order by i;",
+				Expected: []sql.Row{
+					{0, 0.816496580927726, 1.0},
+					{0, 0.816496580927726, 1.0},
+					{0, 0.816496580927726, 1.0},
+					{1, 271.89336144893275, 333.0},
+					{1, 271.89336144893275, 333.0},
+					{1, 271.89336144893275, 333.0},
+				},
+			},
+			{
+				Query: "select i, variance(i) over(), var_samp(i) over() from tt order by i;",
+				Expected: []sql.Row{
+					{0, 0.25, 0.3},
+					{0, 0.25, 0.3},
+					{0, 0.25, 0.3},
+					{1, 0.25, 0.3},
+					{1, 0.25, 0.3},
+					{1, 0.25, 0.3},
+				},
+			},
+			{
+				Query: "select i, variance(j) over(partition by i), var_samp(i) over(partition by i) from tt order by i;",
+				Expected: []sql.Row{
+					{0, 0.6666666666666666, 0.0},
+					{0, 0.6666666666666666, 0.0},
+					{0, 0.6666666666666666, 0.0},
+					{1, 73926.0, 0.0},
+					{1, 73926.0, 0.0},
+					{1, 73926.0, 0.0},
+				},
+			},
+			{
+				Query: "insert into tt values (null, null);",
+				Expected: []sql.Row{
+					{types.NewOkResult(1)},
+				},
+			},
+			{
+				Query: "select i, std(i) over(), std(j) over(), stddev_samp(j) over() from tt order by i;",
+				Expected: []sql.Row{
+					{nil, 0.5, 297.47660972475353, 325.86929895281634},
+					{0, 0.5, 297.47660972475353, 325.86929895281634},
+					{0, 0.5, 297.47660972475353, 325.86929895281634},
+					{0, 0.5, 297.47660972475353, 325.86929895281634},
+					{1, 0.5, 297.47660972475353, 325.86929895281634},
+					{1, 0.5, 297.47660972475353, 325.86929895281634},
+					{1, 0.5, 297.47660972475353, 325.86929895281634},
+				},
+			},
+			{
+				Query: "select i, std(j) over(partition by i), stddev_samp(j) over(partition by i) from tt order by i;",
+				Expected: []sql.Row{
+					{nil, nil, nil},
+					{0, 0.816496580927726, 1.0},
+					{0, 0.816496580927726, 1.0},
+					{0, 0.816496580927726, 1.0},
+					{1, 271.89336144893275, 333.0},
+					{1, 271.89336144893275, 333.0},
+					{1, 271.89336144893275, 333.0},
+				},
+			},
+			{
+				Query: "select i, variance(i) over(), var_samp(i) over() from tt order by i;",
+				Expected: []sql.Row{
+					{nil, 0.25, 0.3},
+					{0, 0.25, 0.3},
+					{0, 0.25, 0.3},
+					{0, 0.25, 0.3},
+					{1, 0.25, 0.3},
+					{1, 0.25, 0.3},
+					{1, 0.25, 0.3},
+				},
+			},
+			{
+				Query: "select i, variance(j) over(partition by i), var_samp(i) over(partition by i) from tt order by i;",
+				Expected: []sql.Row{
+					{nil, nil, nil},
+					{0, 0.6666666666666666, 0.0},
+					{0, 0.6666666666666666, 0.0},
+					{0, 0.6666666666666666, 0.0},
+					{1, 73926.0, 0.0},
+					{1, 73926.0, 0.0},
+					{1, 73926.0, 0.0},
+				},
+			},
+			{
+				Query: "select i, stddev_pop(j) over w, stddev_samp(j) over w, variance(j) over w, var_samp(i) over w from tt window w as (partition by i) order by i;",
+				Expected: []sql.Row{
+					{nil, nil, nil, nil, nil},
+					{0, 0.816496580927726, 1.0, 0.6666666666666666, 0.0},
+					{0, 0.816496580927726, 1.0, 0.6666666666666666, 0.0},
+					{0, 0.816496580927726, 1.0, 0.6666666666666666, 0.0},
+					{1, 271.89336144893275, 333.0, 73926.0, 0.0},
+					{1, 271.89336144893275, 333.0, 73926.0, 0.0},
+					{1, 271.89336144893275, 333.0, 73926.0, 0.0},
+				},
+			},
+		},
+	},
 }
 
 var SpatialScriptTests = []ScriptTest{

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/dolthub/go-icu-regex v0.0.0-20250327004329-6799764f2dad
 	github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71
 	github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81
-	github.com/dolthub/vitess v0.0.0-20250409183615-d8335325e91c
+	github.com/dolthub/vitess v0.0.0-20250410090211-143e6b272ad4
 	github.com/go-kit/kit v0.10.0
 	github.com/go-sql-driver/mysql v1.7.2-0.20231213112541-0004702b931d
 	github.com/gocraft/dbr/v2 v2.7.2

go.sum

@@ -58,10 +58,8 @@ github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71 h1:bMGS25NWAGTE
 github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71/go.mod h1:2/2zjLQ/JOOSbbSboojeg+cAwcRV0fDLzIiWch/lhqI=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81 h1:7/v8q9XGFa6q5Ap4Z/OhNkAMBaK5YeuEzwJt+NZdhiE=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81/go.mod h1:siLfyv2c92W1eN/R4QqG/+RjjX5W2+gCTRjZxBjI3TY=
-github.com/dolthub/vitess v0.0.0-20250325024605-8131be3ca6d3 h1:euU+adNAYw46Zcp1HnoaSDWhqjfaL8s/1SPU+i16gYM=
-github.com/dolthub/vitess v0.0.0-20250325024605-8131be3ca6d3/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
-github.com/dolthub/vitess v0.0.0-20250409183615-d8335325e91c h1:hl+yPanHdJML9aMB0MgrTCpzsd3jIf/o3r8pC6Tqx6E=
-github.com/dolthub/vitess v0.0.0-20250409183615-d8335325e91c/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
+github.com/dolthub/vitess v0.0.0-20250410090211-143e6b272ad4 h1:LGTt2LtYX8vaai32d+c9L0sMcP+Dg9w1kO6+lbsxxYg=
+github.com/dolthub/vitess v0.0.0-20250410090211-143e6b272ad4/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
 github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=

optgen/cmd/source/unary_aggs.yaml

@@ -31,4 +31,12 @@ unaryAggs:
   desc: "returns the minimum value of expr in all rows."
 - name:     "Sum"
   desc:     "returns the sum of expr in all rows"
-  nullable: false
+  nullable: false
+- name:     "StdDevPop"
+  desc:     "returns the population standard deviation of expr"
+- name:     "StdDevSamp"
+  desc:     "returns the sample standard deviation of expr"
+- name:     "VarPop"
+  desc:     "returns the population variance of expr"
+- name:     "VarSamp"
+  desc:     "returns the sample variance of expr"

sql/expression/function/aggregation/common.go

@@ -125,11 +125,11 @@ func (a *unaryAggBase) WithChildren(children ...sql.Expression) (sql.Expression,
 	return &na, nil
 }
 
-func (a unaryAggBase) FunctionName() string {
+func (a *unaryAggBase) FunctionName() string {
 	return a.functionName
 }
 
-func (a unaryAggBase) Description() string {
+func (a *unaryAggBase) Description() string {
 	return a.description
 }