implement ntile

enginetest/queries/script_queries.go

@@ -8107,6 +8107,208 @@ where
 			},
 		},
 	},
+	{
+		Name:    "ntile tests",
+		Dialect: "mysql",
+		SetUpScript: []string{
+			"create table t (i int primary key, j int);",
+			"insert into t values (1, 1), (2, 1), (3, 1), (4, 1), (5, 1), (6, 2), (7, 2), (8, 2), (9, 2), (10, 2);",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query:       "select i, ntile(null) over() from t;",
+				ExpectedErr: sql.ErrInvalidArgument,
+			},
+			{
+				Query:       "select i, ntile(0) over() from t;",
+				ExpectedErr: sql.ErrInvalidArgument,
+			},
+			{
+				Query:       "select i, ntile(-1) over() from t;",
+				ExpectedErr: sql.ErrInvalidArgument,
+			},
+			{
+				Query: "select i, ntile(100) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(2)},
+					{3, uint64(3)},
+					{4, uint64(4)},
+					{5, uint64(5)},
+					{6, uint64(6)},
+					{7, uint64(7)},
+					{8, uint64(8)},
+					{9, uint64(9)},
+					{10, uint64(10)},
+				},
+			},
+			{
+				Query: "select i, ntile(10) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(2)},
+					{3, uint64(3)},
+					{4, uint64(4)},
+					{5, uint64(5)},
+					{6, uint64(6)},
+					{7, uint64(7)},
+					{8, uint64(8)},
+					{9, uint64(9)},
+					{10, uint64(10)},
+				},
+			},
+			{
+				Query: "select i, ntile(9) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(2)},
+					{4, uint64(3)},
+					{5, uint64(4)},
+					{6, uint64(5)},
+					{7, uint64(6)},
+					{8, uint64(7)},
+					{9, uint64(8)},
+					{10, uint64(9)},
+				},
+			},
+			{
+				Query: "select i, ntile(8) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(2)},
+					{4, uint64(2)},
+					{5, uint64(3)},
+					{6, uint64(4)},
+					{7, uint64(5)},
+					{8, uint64(6)},
+					{9, uint64(7)},
+					{10, uint64(8)},
+				},
+			},
+			{
+				Query: "select i, ntile(7) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(2)},
+					{4, uint64(2)},
+					{5, uint64(3)},
+					{6, uint64(3)},
+					{7, uint64(4)},
+					{8, uint64(5)},
+					{9, uint64(6)},
+					{10, uint64(7)},
+				},
+			},
+			{
+				Query: "select i, ntile(6) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(2)},
+					{4, uint64(2)},
+					{5, uint64(3)},
+					{6, uint64(3)},
+					{7, uint64(4)},
+					{8, uint64(4)},
+					{9, uint64(5)},
+					{10, uint64(6)},
+				},
+			},
+			{
+				Query: "select i, ntile(5) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(2)},
+					{4, uint64(2)},
+					{5, uint64(3)},
+					{6, uint64(3)},
+					{7, uint64(4)},
+					{8, uint64(4)},
+					{9, uint64(5)},
+					{10, uint64(5)},
+				},
+			},
+			{
+				Query: "select i, ntile(4) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(1)},
+					{4, uint64(2)},
+					{5, uint64(2)},
+					{6, uint64(2)},
+					{7, uint64(3)},
+					{8, uint64(3)},
+					{9, uint64(4)},
+					{10, uint64(4)},
+				},
+			},
+			{
+				Query: "select i, ntile(3) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(1)},
+					{4, uint64(1)},
+					{5, uint64(2)},
+					{6, uint64(2)},
+					{7, uint64(2)},
+					{8, uint64(3)},
+					{9, uint64(3)},
+					{10, uint64(3)},
+				},
+			},
+			{
+				Query: "select i, ntile(2) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(1)},
+					{4, uint64(1)},
+					{5, uint64(1)},
+					{6, uint64(2)},
+					{7, uint64(2)},
+					{8, uint64(2)},
+					{9, uint64(2)},
+					{10, uint64(2)},
+				},
+			},
+			{
+				Query: "select i, ntile(1) over() from t;",
+				Expected: []sql.Row{
+					{1, uint64(1)},
+					{2, uint64(1)},
+					{3, uint64(1)},
+					{4, uint64(1)},
+					{5, uint64(1)},
+					{6, uint64(1)},
+					{7, uint64(1)},
+					{8, uint64(1)},
+					{9, uint64(1)},
+					{10, uint64(1)},
+				},
+			},
+			{
+				Query: "select i, j, ntile(2) over(partition by j) from t;",
+				Expected: []sql.Row{
+					{1, 1, uint64(1)},
+					{2, 1, uint64(1)},
+					{3, 1, uint64(1)},
+					{4, 1, uint64(2)},
+					{5, 1, uint64(2)},
+					{6, 2, uint64(1)},
+					{7, 2, uint64(1)},
+					{8, 2, uint64(1)},
+					{9, 2, uint64(2)},
+					{10, 2, uint64(2)},
+				},
+			},
+		},
+	},
 }
 
 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 v0.0.0-20250410090211-143e6b272ad4
+	github.com/dolthub/vitess v0.0.0-20250410233614-8d8c7a5b3d6b
 	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

@@ -58,8 +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 v0.0.0-20250410090211-143e6b272ad4 h1:LGTt2LtYX8vaai32d+c9L0sMcP+Dg9w1kO6+lbsxxYg=
-github.com/dolthub/vitess v0.0.0-20250410090211-143e6b272ad4/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
+github.com/dolthub/vitess v0.0.0-20250410233614-8d8c7a5b3d6b h1:2wE+qJwJ5SRIzz+dJQT8XbkpK+g8/pFt34AU/iJ5K+Y=
+github.com/dolthub/vitess v0.0.0-20250410233614-8d8c7a5b3d6b/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

@@ -32,11 +32,11 @@ unaryAggs:
 - name:     "Sum"
   desc:     "returns the sum of expr in all rows"
   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"
+- 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/window/ntile.go

@@ -0,0 +1,142 @@
+// Copyright 2025 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package window
+
+import (
+	"strings"
+
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/expression/function/aggregation"
+	"github.com/dolthub/go-mysql-server/sql/types"
+)
+
+type NTile struct {
+	pos   uint64
+	count uint64
+
+	bucketExpr sql.Expression
+	bucketSize uint64
+
+	id     sql.ColumnId
+	window *sql.WindowDefinition
+}
+
+var _ sql.FunctionExpression = (*NTile)(nil)
+var _ sql.WindowAggregation = (*NTile)(nil)
+var _ sql.WindowAdaptableExpression = (*NTile)(nil)
+var _ sql.CollationCoercible = (*NTile)(nil)
+
+func NewNTile(expr sql.Expression) sql.Expression {
+	return &NTile{
+		bucketExpr: expr,
+	}
+}
+
+// Id implements sql.IdExpression
+func (n *NTile) Id() sql.ColumnId {
+	return n.id
+}
+
+// WithId implements sql.IdExpression
+func (n *NTile) WithId(id sql.ColumnId) sql.IdExpression {
+	ret := *n
+	ret.id = id
+	return &ret
+}
+
+// Description implements sql.FunctionExpression
+func (n *NTile) Description() string {
+	return "returns percentage rank value."
+}
+
+// Window implements sql.WindowExpression
+func (n *NTile) Window() *sql.WindowDefinition {
+	return n.window
+}
+
+func (n *NTile) Resolved() bool {
+	return windowResolved(n.window)
+}
+
+func (n *NTile) String() string {
+	sb := strings.Builder{}
+	sb.WriteString("ntile()")
+	if n.window != nil {
+		sb.WriteString(" ")
+		sb.WriteString(n.window.String())
+	}
+	return sb.String()
+}
+
+func (n *NTile) DebugString() string {
+	sb := strings.Builder{}
+	sb.WriteString("ntile()")
+	if n.window != nil {
+		sb.WriteString(" ")
+		sb.WriteString(sql.DebugString(n.window))
+	}
+	return sb.String()
+}
+
+// FunctionName implements sql.FunctionExpression
+func (n *NTile) FunctionName() string {
+	return "NTILE"
+}
+
+// Type implements sql.Expression
+func (n *NTile) Type() sql.Type {
+	return types.Float64
+}
+
+// CollationCoercibility implements the interface sql.CollationCoercible.
+func (*NTile) CollationCoercibility(ctx *sql.Context) (collation sql.CollationID, coercibility byte) {
+	return sql.Collation_binary, 5
+}
+
+// IsNullable implements sql.Expression
+func (n *NTile) IsNullable() bool {
+	return false
+}
+
+// Eval implements sql.Expression
+func (n *NTile) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
+	return nil, sql.ErrWindowUnsupported.New(n.FunctionName())
+}
+
+// Children implements sql.Expression
+func (n *NTile) Children() []sql.Expression {
+	return n.window.ToExpressions()
+}
+
+// WithChildren implements sql.Expression
+func (n *NTile) WithChildren(children ...sql.Expression) (sql.Expression, error) {
+	window, err := n.window.FromExpressions(children)
+	if err != nil {
+		return nil, err
+	}
+
+	return n.WithWindow(window), nil
+}
+
+// WithWindow implements sql.WindowAggregation
+func (n *NTile) WithWindow(window *sql.WindowDefinition) sql.WindowAdaptableExpression {
+	nr := *n
+	nr.window = window
+	return &nr
+}
+
+func (n *NTile) NewWindowFunction() (sql.WindowFunction, error) {
+	return aggregation.NewNTile(n.bucketExpr), nil
+}