make update join case insensitive (#3000)

Author: jycor

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{

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

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
 		}
 	}