Question

我将数据从SQL Server 2012表中提取到SQL SMO表中，然后循环遍历结果集。执行以下操作时，我在运行时收到内存不足错误：

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<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
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<body data-spy="scroll" data-target=".navbar">
  <!-- The navbar where the anchors <a> are used ot jump to a section in the scrollable container -->
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    <div class="container-fluid">
      <div class="navbar-header">
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        </button>
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      <a class="navbar-brand" href="#">Site</a>
      </div>
      <div class="collapse navbar-collapse" id="myNavbar">
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          <li><a href="#section1">Section1</a></li>
          <li><a href="#section2">Section2</a></li>
          <li><a href="#section3">Section3</a></li>
        </ul>
      </div>
    </div>
  </nav>
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  <div id="section1" class="container-fluid">
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它不会抛出错误，直到它遇到具有〜15MB（15127052字节）的DATALENGTH（[Data]）的行。

BitConverter.ToString（byte []）可以处理二进制数据的最大大小吗？

Answer 1

它实际上与SMO和数据库完全无关，而且与string.Replace()函数的明显限制有关。我打破了LINQ代码，以便逐步操作数据，并发现当我尝试执行s.Replace("-", "")时，这就是错误的地方。在Stack Exchange上挖掘了一下之后我发现：Does string.Replace(string, string) create additional strings?应用我在那里找到的东西，我将代码从使用字符串更改为使用StringBuilder，然后使用StringBuilder.Replace(string, string)函数并且它可以工作。显然因为string.Replace(string, string)创建源字符串的副本，必须存在某种内存限制，但由于StringBuilder对原始字符串而不是副本进行操作，因此该限制不适用。

最后代码最终看起来像：

StringBuilder sb = new StringBuilder(dr["Data"] == DBNull.Value ? "NULL" : BitConverter.ToString((byte[])dr["Data"]));

sb.Replace("-", "");

感谢您的帮助。

BitConverter.ToString（byte []）可以从SQL SMO查询处理的最大长度是多少？

1 个答案: