尽管有查询字符串，但使用sql COUNT时ExecuteNonQuery返回-1 [英] ExecuteNonQuery returning -1 when using sql COUNT despite the query string

问题描述

由于某种原因，C＃中的 ExecuteNonQuery（）返回 -1 ，尽管当我单独运行查询时，该值将返回所需的实际值。

For some reason, ExecuteNonQuery() in C# returns -1, though when I run a query separately, the value returns the actual value needed.

例如：

try
{

    var connString ="Data Source=ServerName;InitialCatalog=DatabaseName;Integrated Security=true;"
    SqlConnection conn = new SqlConnection(connString);

    SqlCommand someCmd = new SqlCommand("SELECT COUNT(*) FROM SomeTable");

    someCmd.Connection = conn;

    conn.Open();

    var theCount = cmd.ExecuteNonQuery();

    conn.Close();
}
catch(Exception ex)
{
    Console.WriteLine(ex.Message);
}

在执行命令时，它返回 -1 。尽管如果单独运行查询，

When the command is executed it returns -1. Though if run the query separately,

SELECT COUNT(*) FROM SomeTable;

列返回计数为 4 如果要查询的表有 4 行。

Column returns one row with a count of 4 if that table being queried has 4 rows.

推荐答案

基于 MSDN ：

用于UPDATE，INSERT和DELETE语句，返回值是该命令影响的行数。当要插入或更新的表上存在触发器时，返回值包括受插入或更新操作影响的行数以及受一个或多个触发器影响的行数。对于所有其他类型的语句，返回值为-1。如果发生回滚，则返回值也为-1。

For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. When a trigger exists on a table being inserted or updated, the return value includes the number of rows affected by both the insert or update operation and the number of rows affected by the trigger or triggers. For all other types of statements, the return value is -1. If a rollback occurs, the return value is also -1.

您要返回受命令影响的行数并保存将其保存为 int 变量，但由于语句类型为 select ，因此它返回 -1 。

You want to return the number of rows affected by the command and save it to an int variable but since the type of statement is select so it returns -1.

解决方案：如果要获取受SELECT命令影响的行数并将其保存到您可以使用 ExecuteScalar 。

Solution: If you want to get the number of rows affected by the SELECT command and save it to an int variable you can use ExecuteScalar.

var theCount = (int)cmd.ExecuteScalar();

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