refactor: 移除antlr4减小包体积&ai助手优化

server/internal/db/dbm/sqlparser/tokenizer/token.go

@@ -0,0 +1,63 @@
+package tokenizer
+
+import "strings"
+
+// TokenType 表示词法单元类型
+type TokenType int
+
+const (
+	TokenEOF TokenType = iota
+	TokenKeyword
+	TokenIdentifier
+	TokenString
+	TokenNumber
+	TokenOperator
+	TokenPunctuation
+)
+
+// Token 是一个词法单元
+type Token struct {
+	Type  TokenType
+	Value string
+	Pos   int // 在原始 SQL 中的起始位置
+	End   int // 在原始 SQL 中的结束位置（不包含）
+}
+
+// IsKeyword 判断当前 token 是否匹配任意给定关键字（大小写不敏感）
+func (t Token) IsKeyword(keywords ...string) bool {
+	if t.Type != TokenKeyword {
+		return false
+	}
+	upper := strings.ToUpper(t.Value)
+	for _, kw := range keywords {
+		if upper == strings.ToUpper(kw) {
+			return true
+		}
+	}
+	return false
+}
+
+// IsEOF 判断是否为 EOF token
+func (t Token) IsEOF() bool {
+	return t.Type == TokenEOF
+}
+
+// Keywords 是 SQL 标准关键字集合
+var Keywords = map[string]bool{
+	"SELECT": true, "FROM": true, "WHERE": true, "INSERT": true, "INTO": true,
+	"UPDATE": true, "SET": true, "DELETE": true, "CREATE": true, "DROP": true,
+	"ALTER": true, "TABLE": true, "DATABASE": true, "INDEX": true, "VIEW": true,
+	"JOIN": true, "LEFT": true, "RIGHT": true, "INNER": true, "OUTER": true,
+	"NATURAL": true, "CROSS": true, "FULL": true, "ON": true, "AS": true,
+	"UNION": true, "ALL": true, "DISTINCT": true, "LIMIT": true, "OFFSET": true,
+	"ORDER": true, "BY": true, "GROUP": true, "HAVING": true, "WITH": true,
+	"SHOW": true, "VALUES": true, "AND": true, "OR": true, "NOT": true,
+	"NULL": true, "TRUE": true, "FALSE": true, "DESC": true, "ASC": true,
+	"IS": true, "LIKE": true, "IN": true, "BETWEEN": true, "EXISTS": true,
+	"CASE": true, "WHEN": true, "THEN": true, "ELSE": true, "END": true,
+	"IF": true, "FOR": true, "PRIMARY": true, "KEY": true, "FOREIGN": true,
+	"REFERENCES": true, "UNIQUE": true, "DEFAULT": true, "AUTO_INCREMENT": true,
+	"COMMENT": true, "ENGINE": true, "CHARSET": true, "COLLATE": true,
+	"RETURNING": true, "ONLY": true, "SIMILAR": true, "ESCAPE": true,
+	"INTERVAL": true, "CAST": true,
+}