dialect/sql/sqljson: quote non-identifiers (#2910)

* dialect/sql: fixed invalid json path quote

* fix: fixed empty string

* fix: fixed lint issue

* Apply suggestions from code review

Co-authored-by: Ariel Mashraki <7413593+a8m@users.noreply.github.com>

* fix: added test to new case

Co-authored-by: Ariel Mashraki <7413593+a8m@users.noreply.github.com>

dialect/sql/sqljson/sqljson.go

@@ -430,15 +430,18 @@ func (p *PathOptions) mysqlFunc(fn string, b *sql.Builder) {
 
 // mysqlPath writes the JSON path in MySQL (or SQLite) format.
 func (p *PathOptions) mysqlPath(b *sql.Builder) {
-	b.WriteString(`"$`)
+	b.WriteString(`'$`)
 	for _, p := range p.Path {
-		if _, ok := isJSONIdx(p); ok {
+		switch _, isIndex := isJSONIdx(p); {
+		case isIndex:
 			b.WriteString(p)
-		} else {
+		case p == "*" || isQuoted(p) || isIdentifier(p):
 			b.WriteString("." + p)
+		default:
+			b.WriteString(`."` + p + `"`)
 		}
 	}
-	b.WriteByte('"')
+	b.WriteByte('\'')
 }
 
 // pgPath writes the JSON path in Postgres format `"a"->'b'->>'c'`.
@@ -529,6 +532,25 @@ func normalizePG(b *sql.Builder, arg any, opts []Option) []Option {
 	return append(base, opts...)
 }
 
+func isIdentifier(name string) bool {
+	if name == "" {
+		return false
+	}
+	for i, c := range name {
+		if !unicode.IsLetter(c) && c != '_' && (i == 0 || !unicode.IsDigit(c)) {
+			return false
+		}
+	}
+	return true
+}
+
+func isQuoted(s string) bool {
+	if s == "" {
+		return false
+	}
+	return s[0] == '"' && s[len(s)-1] == '"'
+}
+
 // isJSONIdx reports whether the string represents a JSON index.
 func isJSONIdx(s string) (string, bool) {
 	if len(s) > 2 && s[0] == '[' && s[len(s)-1] == ']' && isNumber(s[1:len(s)-1]) {