From a8cc934dde1539c2e46f8a65153851c2ddc29739 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Thu, 29 May 2025 14:30:52 -0700
Subject: [PATCH 1/2] make update join case insensitive

---
 enginetest/queries/script_queries.go | 50 ++++++++++++++++++++++++++++
 sql/analyzer/unnest_insubqueries.go  |  2 ++
 sql/plan/update_join.go              |  3 ++
 sql/rowexec/update.go                | 14 ++++----
 4 files changed, 62 insertions(+), 7 deletions(-)

diff --git a/enginetest/queries/script_queries.go b/enginetest/queries/script_queries.go
index f8883ba7ec..540016559c 100644
--- a/enginetest/queries/script_queries.go
+++ b/enginetest/queries/script_queries.go
@@ -8477,6 +8477,56 @@ where
 			},
 		},
 	},
+	{
+		// This is a script test here because every table in the harness setup data is in all lowercase
+		Name:    "case insensitive update with insubqueries and update joins",
+		Dialect: "mysql",
+		SetUpScript: []string{
+			"create table MiXeDcAsE (i int primary key, j int)",
+			"insert into mixedcase values (1, 1);",
+			"insert into mixedcase values (2, 2);",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query: "update mixedcase set j = 999 where i in (select 1)",
+				Expected: []sql.Row{
+					{types.OkResult{
+						RowsAffected: 1,
+						Info: plan.UpdateInfo{
+							Matched: 1,
+							Updated: 1,
+						},
+					}},
+				},
+			},
+			{
+				Query: "select * from mixedcase;",
+				Expected: []sql.Row{
+					{1, 999},
+					{2, 2},
+				},
+			},
+			{
+				Query: " with cte(x) as (select 2) update mixedcase set j = 999 where i in (select x from cte)",
+				Expected: []sql.Row{
+					{types.OkResult{
+						RowsAffected: 1,
+						Info: plan.UpdateInfo{
+							Matched: 1,
+							Updated: 1,
+						},
+					}},
+				},
+			},
+			{
+				Query: "select * from mixedcase;",
+				Expected: []sql.Row{
+					{1, 999},
+					{2, 999},
+				},
+			},
+		},
+	},
 }
 
 var SpatialScriptTests = []ScriptTest{
diff --git a/sql/analyzer/unnest_insubqueries.go b/sql/analyzer/unnest_insubqueries.go
index c5f566373b..9b9dc6bba0 100644
--- a/sql/analyzer/unnest_insubqueries.go
+++ b/sql/analyzer/unnest_insubqueries.go
@@ -45,6 +45,8 @@ func unnestInSubqueries(ctx *sql.Context, a *Analyzer, n sql.Node, scope *plan.S
 	}
 
 	switch n.(type) {
+	case *plan.Update:
+		print()
 	case *plan.DeleteFrom, *plan.InsertInto:
 		return n, transform.SameTree, nil
 	}
diff --git a/sql/plan/update_join.go b/sql/plan/update_join.go
index f2c6e8ff30..814e953a26 100644
--- a/sql/plan/update_join.go
+++ b/sql/plan/update_join.go
@@ -15,6 +15,8 @@
 package plan
 
 import (
+	"strings"
+
 	"github.com/dolthub/go-mysql-server/sql"
 )
 
@@ -232,6 +234,7 @@ func SplitRowIntoTableRowMap(row sql.Row, joinSchema sql.Schema) map[string]sql.
 		}
 	}
 
+	currentTable = strings.ToLower(currentTable)
 	ret[currentTable] = currentRow
 
 	return ret
diff --git a/sql/rowexec/update.go b/sql/rowexec/update.go
index 91ad67ddb5..2c4cf4eff1 100644
--- a/sql/rowexec/update.go
+++ b/sql/rowexec/update.go
@@ -17,6 +17,7 @@ package rowexec
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/plan"
@@ -230,7 +231,7 @@ func (u *updateJoinIter) Next(ctx *sql.Context) (sql.Row, error) {
 		tableToNewRowMap := plan.SplitRowIntoTableRowMap(newJoinRow, u.joinSchema)
 
 		for tableName, _ := range u.updaters {
-			oldTableRow := tableToOldRowMap[tableName]
+			oldTableRow := tableToOldRowMap[strings.ToLower(tableName)]
 
 			// Handle the case of row being ignored due to it not being valid in the join row.
 			if isRightOrLeftJoin(u.joinNode) {
@@ -388,15 +389,14 @@ func recreateRowFromMap(rowMap map[string]sql.Row, joinSchema sql.Schema) sql.Ro
 		return ret
 	}
 
-	currentTable := joinSchema[0].Source
+	currentTable := strings.ToLower(joinSchema[0].Source)
 	ret = append(ret, rowMap[currentTable]...)
 
 	for i := 1; i < len(joinSchema); i++ {
-		c := joinSchema[i]
-
-		if c.Source != currentTable {
-			ret = append(ret, rowMap[c.Source]...)
-			currentTable = c.Source
+		newTable := strings.ToLower(joinSchema[i].Source)
+		if !strings.EqualFold(newTable, currentTable) {
+			ret = append(ret, rowMap[newTable]...)
+			currentTable = newTable
 		}
 	}
 

From ce0922d8325ed576a818295c50e923a870feb662 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Thu, 29 May 2025 14:31:35 -0700
Subject: [PATCH 2/2] remove debug

---
 sql/analyzer/unnest_insubqueries.go | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sql/analyzer/unnest_insubqueries.go b/sql/analyzer/unnest_insubqueries.go
index 9b9dc6bba0..c5f566373b 100644
--- a/sql/analyzer/unnest_insubqueries.go
+++ b/sql/analyzer/unnest_insubqueries.go
@@ -45,8 +45,6 @@ func unnestInSubqueries(ctx *sql.Context, a *Analyzer, n sql.Node, scope *plan.S
 	}
 
 	switch n.(type) {
-	case *plan.Update:
-		print()
 	case *plan.DeleteFrom, *plan.InsertInto:
 		return n, transform.SameTree, nil
 	}