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Merged
Hydrocharged merged 1 commit into from
Jan 10, 2026
Merged

Added DISTINCT ON handling #2181

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4 changes: 2 additions & 2 deletions go.mod
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Original file line number Diff line number Diff line change
Expand Up @@ -9,10 +9,10 @@ require (
github.com/dolthub/dolt/go v0.40.5-0.20260108000424-ed62ee89285b
github.com/dolthub/eventsapi_schema v0.0.0-20250915094920-eadfd39051ca
github.com/dolthub/flatbuffers/v23 v23.3.3-dh.2
github.com/dolthub/go-mysql-server v0.20.1-0.20260108224859-4dd05696542e
github.com/dolthub/go-mysql-server v0.20.1-0.20260110001532-5eb9ccaba8a1
github.com/dolthub/pg_query_go/v6 v6.0.0-20251215122834-fb20be4254d1
github.com/dolthub/sqllogictest/go v0.0.0-20240618184124-ca47f9354216
github.com/dolthub/vitess v0.0.0-20260108222406-f8a2587c4954
github.com/dolthub/vitess v0.0.0-20260109110924-205efc8530f1
github.com/fatih/color v1.13.0
github.com/goccy/go-json v0.10.2
github.com/gogo/protobuf v1.3.2
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8 changes: 4 additions & 4 deletions go.sum
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Original file line number Diff line number Diff line change
Expand Up @@ -238,8 +238,8 @@ github.com/dolthub/fslock v0.0.3 h1:iLMpUIvJKMKm92+N1fmHVdxJP5NdyDK5bK7z7Ba2s2U=
github.com/dolthub/fslock v0.0.3/go.mod h1:QWql+P17oAAMLnL4HGB5tiovtDuAjdDTPbuqx7bYfa0=
github.com/dolthub/go-icu-regex v0.0.0-20250916051405-78a38d478790 h1:zxMsH7RLiG+dlZ/y0LgJHTV26XoiSJcuWq+em6t6VVc=
github.com/dolthub/go-icu-regex v0.0.0-20250916051405-78a38d478790/go.mod h1:F3cnm+vMRK1HaU6+rNqQrOCyR03HHhR1GWG2gnPOqaE=
github.com/dolthub/go-mysql-server v0.20.1-0.20260108224859-4dd05696542e h1:OKp5W4bgSJIAKESEtBtyOWF85HwvE7UIe+T204v5EN0=
github.com/dolthub/go-mysql-server v0.20.1-0.20260108224859-4dd05696542e/go.mod h1:2bgnal91FRGVdJyirmUSMCd1Tp3Ci8dTDsrJWkTp/hs=
github.com/dolthub/go-mysql-server v0.20.1-0.20260110001532-5eb9ccaba8a1 h1:n2BXaNdJZWPu7Bpeeb0gSxG0fHqfFWCiO2Agcyygndo=
github.com/dolthub/go-mysql-server v0.20.1-0.20260110001532-5eb9ccaba8a1/go.mod h1:ZODUC6XlqCx3DgHl6x7cWwMR0uq7XzVU0adsJvjZJTY=
github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63 h1:OAsXLAPL4du6tfbBgK0xXHZkOlos63RdKYS3Sgw/dfI=
github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63/go.mod h1:lV7lUeuDhH5thVGDCKXbatwKy2KW80L4rMT46n+Y2/Q=
github.com/dolthub/ishell v0.0.0-20240701202509-2b217167d718 h1:lT7hE5k+0nkBdj/1UOSFwjWpNxf+LCApbRHgnCA17XE=
Expand All @@ -250,8 +250,8 @@ github.com/dolthub/pg_query_go/v6 v6.0.0-20251215122834-fb20be4254d1 h1:GY17cGA4
github.com/dolthub/pg_query_go/v6 v6.0.0-20251215122834-fb20be4254d1/go.mod h1:qnrZP3/1slFl2Bq5yw38HLOsArZareGwdpEceriblLc=
github.com/dolthub/sqllogictest/go v0.0.0-20240618184124-ca47f9354216 h1:JWkKRE4EHUcEVQCMRBej8DYxjYjRz/9MdF/NNQh0o70=
github.com/dolthub/sqllogictest/go v0.0.0-20240618184124-ca47f9354216/go.mod h1:e/FIZVvT2IR53HBCAo41NjqgtEnjMJGKca3Y/dAmZaA=
github.com/dolthub/vitess v0.0.0-20260108222406-f8a2587c4954 h1:VN2ZjnYPyxcAN/XetvcdumFbI2Ad/Gb47Qwdo9REY3A=
github.com/dolthub/vitess v0.0.0-20260108222406-f8a2587c4954/go.mod h1:FLWqdXsAeeBQyFwDjmBVu0GnbjI2MKeRf3tRVdJEKlI=
github.com/dolthub/vitess v0.0.0-20260109110924-205efc8530f1 h1:souetbYNBRHrt9y990VGD1jkzCIQ0jC+gxMdFOEjL+g=
github.com/dolthub/vitess v0.0.0-20260109110924-205efc8530f1/go.mod h1:FLWqdXsAeeBQyFwDjmBVu0GnbjI2MKeRf3tRVdJEKlI=
github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
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17 changes: 14 additions & 3 deletions server/ast/select_clause.go
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,6 @@
package ast

import (
"github.com/cockroachdb/errors"
"github.com/dolthub/go-mysql-server/sql/expression"

vitess "github.com/dolthub/vitess/go/vt/sqlparser"
Expand Down Expand Up @@ -160,8 +159,17 @@ PostJoinRewrite:
}
}
}
distinct := node.Distinct
var distinctOn vitess.Exprs
if len(node.DistinctOn) > 0 {
return nil, errors.Errorf("DISTINCT ON is not yet supported")
distinct = true
distinctOn = make(vitess.Exprs, len(node.DistinctOn))
for i, expr := range node.DistinctOn {
distinctOn[i], err = nodeExpr(ctx, expr)
if err != nil {
return nil, err
}
}
}
where, err := nodeWhere(ctx, node.Where)
if err != nil {
Expand All @@ -180,7 +188,10 @@ PostJoinRewrite:
return nil, err
}
return &vitess.Select{
QueryOpts: vitess.QueryOpts{Distinct: node.Distinct},
QueryOpts: vitess.QueryOpts{
Distinct: distinct,
DistinctOn: distinctOn,
},
SelectExprs: selectExprs,
From: from,
Where: where,
Expand Down
107 changes: 107 additions & 0 deletions testing/go/select_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,113 @@ import (
// TestSelect covers SELECT syntax not covered by our MySQL select tests
func TestSelect(t *testing.T) {
RunScripts(t, []ScriptTest{
{
Name: "SELECT DISTINCT ON",
SetUpScript: []string{
"CREATE TABLE test (v1 INT4, v2 INT4);",
"INSERT INTO test VALUES (1, 3), (1, 4), (2, 3), (2, 4);",
"CREATE TABLE test2 (v1 INT4, v2 INT4, v3 INT4);",
"INSERT INTO test2 VALUES (1, 3, 5), (2, 3, 5), (1, 4, 5), (2, 4, 5);",
},
Assertions: []ScriptTestAssertion{
{
Query: "SELECT * FROM test ORDER BY v1, v2;",
Expected: []sql.Row{
{1, 3},
{1, 4},
{2, 3},
{2, 4},
},
},
{
Query: "SELECT DISTINCT * FROM test ORDER BY v1, v2;",
Expected: []sql.Row{
{1, 3},
{1, 4},
{2, 3},
{2, 4},
},
},
{
Query: "SELECT DISTINCT ON(v1) * FROM test ORDER BY v1, v2;",
Expected: []sql.Row{
{1, 3},
{2, 3},
},
},
{
Query: "SELECT DISTINCT ON(v2) * FROM test ORDER BY v2, v1;",
Expected: []sql.Row{
{1, 3},
{1, 4},
},
},
{
Query: "SELECT DISTINCT ON(v1) * FROM test ORDER BY v2, v1;",
ExpectedErr: sql.ErrDistinctOnMatchOrderBy.Message,
},
{
Query: "SELECT DISTINCT ON(v2) * FROM test ORDER BY v2 DESC, v1 DESC;",
Expected: []sql.Row{
{2, 4},
{2, 3},
},
},
{
Query: "SELECT DISTINCT ON(v2, v1) * FROM test2 ORDER BY v1, v2;",
Expected: []sql.Row{
{1, 3, 5},
{1, 4, 5},
{2, 3, 5},
{2, 4, 5},
},
},
{
Query: "SELECT DISTINCT ON(v2, v1) * FROM test2 ORDER BY v1, v2 DESC;",
Expected: []sql.Row{
{1, 4, 5},
{1, 3, 5},
{2, 4, 5},
{2, 3, 5},
},
},
{
Query: "SELECT DISTINCT ON(v2, v1) * FROM test2 ORDER BY v1, v2 LIMIT 1;",
Expected: []sql.Row{
{1, 3, 5},
},
},
{
Query: "SELECT DISTINCT ON(v2, v1) * FROM test2 ORDER BY v1, v2 DESC LIMIT 1;",
Expected: []sql.Row{
{1, 4, 5},
},
},
{
Query: "SELECT DISTINCT ON(v1, v2, v3) * FROM test2 ORDER BY v1, v2;",
Expected: []sql.Row{
{1, 3, 5},
{1, 4, 5},
{2, 3, 5},
{2, 4, 5},
},
},
{
Query: "SELECT DISTINCT ON(v3) v1 FROM test2;",
Expected: []sql.Row{
{1},
},
},
{
Query: "SELECT DISTINCT ON(v1, v3) * FROM test2 ORDER BY v1, v2;",
ExpectedErr: sql.ErrDistinctOnMatchOrderBy.Message,
},
{
Query: "SELECT DISTINCT ON(v2) * FROM test2 ORDER BY v1, v2;",
ExpectedErr: sql.ErrDistinctOnMatchOrderBy.Message,
},
},
},
{
Name: "select values",
Assertions: []ScriptTestAssertion{
Expand Down