优化 string 字符串

mybatis-plus-extension/src/main/java/com/baomidou/mybatisplus/extension/plugins/pagination/dialects/MySqlDialect.java

@@ -28,12 +28,13 @@ public class MySqlDialect implements IDialect {
 
     @Override
     public DialectModel buildPaginationSql(String originalSql, long offset, long limit) {
+        StringBuilder sql = new StringBuilder();
+        sql.append(originalSql).append(" LIMIT ").append(FIRST_MARK);
         if (offset != 0L) {
-            String sql = originalSql + " LIMIT " + FIRST_MARK + StringPool.COMMA + SECOND_MARK;
-            return new DialectModel(sql, offset, limit).setConsumerChain();
+            sql.append(StringPool.COMMA).append(SECOND_MARK);
+            return new DialectModel(sql.toString(), offset, limit).setConsumerChain();
         } else {
-            String sql = originalSql + " LIMIT " + FIRST_MARK;
-            return new DialectModel(sql, limit).setConsumer(true);
+            return new DialectModel(sql.toString(), limit).setConsumer(true);
         }
     }
 }