From e80853e7f5eb5313be1c41ae122b34335cbafcf7 Mon Sep 17 00:00:00 2001
From: heige <daheige@users.noreply.github.com>
Date: Sun, 7 Feb 2021 10:12:13 +0800
Subject: [PATCH] optimization check for ParseCheckConstraints (#4063)

---
 schema/check.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/schema/check.go b/schema/check.go
index 7d31ec70..ec66bad2 100644
--- a/schema/check.go
+++ b/schema/check.go
@@ -5,6 +5,11 @@ import (
 	"strings"
 )
 
+var (
+	// match English letters and midline
+	regEnLetterAndmidline = regexp.MustCompile("^[A-Za-z-_]+$")
+)
+
 type Check struct {
 	Name       string
 	Constraint string // length(phone) >= 10
@@ -17,7 +22,7 @@ func (schema *Schema) ParseCheckConstraints() map[string]Check {
 	for _, field := range schema.FieldsByDBName {
 		if chk := field.TagSettings["CHECK"]; chk != "" {
 			names := strings.Split(chk, ",")
-			if len(names) > 1 && regexp.MustCompile("^[A-Za-z-_]+$").MatchString(names[0]) {
+			if len(names) > 1 && regEnLetterAndmidline.MatchString(names[0]) {
 				checks[names[0]] = Check{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
 			} else {
 				if names[0] == "" {