fix case insensitivity for str to date

Author: James Cor

enginetest/queries/queries.go

@@ -10520,10 +10520,18 @@ var DateParseQueries = []QueryTest{
 		Query:    "SELECT STR_TO_DATE('a09:30:17','a%h:%i:%s')",
 		Expected: []sql.Row{{"09:30:17"}},
 	},
+	{
+		Query:    "SELECT STR_TO_DATE('A09:30:17','A%h:%i:%s')",
+		Expected: []sql.Row{{"09:30:17"}},
+	},
 	{
 		Query:    "SELECT STR_TO_DATE('a09:30:17','%h:%i:%s')",
 		Expected: []sql.Row{{nil}},
 	},
+	{
+		Query:    "SELECT STR_TO_DATE('A09:30:17','a%h:%i:%s')",
+		Expected: []sql.Row{{nil}},
+	},
 	{
 		Query:    "SELECT STR_TO_DATE('09:30:17a','%h:%i:%s')",
 		Expected: []sql.Row{{"09:30:17"}},

sql/planbuilder/dateparse/date.go

@@ -51,7 +51,7 @@ func ParseDateWithFormat(date, format string) (interface{}, error) {
 	date = strings.TrimSpace(date)
 
 	// convert to all lowercase
-	date = strings.ToLower(date)
+	//date = strings.ToLower(date)
 
 	var dt datetime
 	target := date
@@ -272,7 +272,7 @@ func boolPtr(a bool) *bool { return &a }
 
 // Convert a week abbreviation to a defined weekday.
 func weekdayAbbrev(abbrev string) (time.Weekday, bool) {
-	switch abbrev {
+	switch strings.ToLower(abbrev) {
 	case "sun":
 		return time.Sunday, true
 	case "mon":
@@ -293,7 +293,7 @@ func weekdayAbbrev(abbrev string) (time.Weekday, bool) {
 
 // Convert a month abbreviation to a defined month.
 func monthAbbrev(abbrev string) (time.Month, bool) {
-	switch abbrev {
+	switch strings.ToLower(abbrev) {
 	case "jan":
 		return time.January, true
 	case "feb":
@@ -327,7 +327,7 @@ func monthAbbrev(abbrev string) (time.Month, bool) {
 func monthName(name string) (month time.Month, charCount int, ok bool) {
 	for i := 1; i < 13; i++ {
 		m := time.Month(i)
-		if strings.HasPrefix(name, strings.ToLower(m.String())) {
+		if strings.HasPrefix(strings.ToLower(name), strings.ToLower(m.String())) {
 			return m, len(m.String()), true
 		}
 	}

sql/planbuilder/dateparse/parsers.go

@@ -2,7 +2,8 @@ package dateparse
 
 import (
 	"fmt"
-	"time"
+	"strings"
+"time"
 )
 
 // parser defines a function that processes a string and returns the
@@ -39,7 +40,7 @@ func parseAmPm(result *datetime, chars string) (rest string, _ error) {
 	if len(chars) < 2 {
 		return "", fmt.Errorf("expected > 2 chars, found %d", len(chars))
 	}
-	switch chars[:2] {
+	switch strings.ToLower(chars[:2]) {
 	case "am":
 		result.am = boolPtr(true)
 	case "pm":