C# 使用C对Excel进行选择，如何使其不区分大小写？

此选择按预期查找Kelly：

从[Data$]中选择[First Name]、[Last Name]，其中[First Name]类似于%Kelly%

在Excel电子表格中，第一个名字是Kelly，带大写字母K-，选择也指定大写字母K

但是，如果K in>like%Kelly%<是小写形式的%Kelly%，则找不到该记录。SELECT是区分大小写的

SQL Server似乎没有可以应用于数据库列的lower或lcase方法？？？！！！。这是真的吗？网络上的广泛建议是，在SQL语句中附加COLLATE SQL\u Latin1\u General\u CP1\u CI\u AS，执行ExecuteReader时会产生错误IErrorInfo.GetDescription失败0x80004005

有人能建议一种方法，让我的SQL选择不区分大小写吗

我已将代码粘贴到下面

当传递有效字符串时，f.vs方法返回true，即IsEmptyOrNull为false的字符串

蒂亚-霍伊特斯特

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SQL Server确实有一个名为的函数，该函数将字符串转换为所有小写字母

[COLLATE SQL\u Latin1\u General\u CP1\u CI\u AS]仅在SQL Server中工作。从您的问题中我可以看出，您没有使用SQL Server；您正在使用OLEDB数据源查询Excel文件，在这种情况下，UCASE应该可以工作：

if (f.vs(firstName))
    select += "UCase([First Name]) like \"%" + firstName.ToUpper() + "%\" and ";
if (f.vs(lastName))
    select += "UCase([Last Name]) like \"%" + lastName.ToUpper() + "%\" and ";

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成功了，非常感谢，肯！Excel不是SQL Server，是吗！：

        // Build the select; [Data$] is the name of the worksheet
        string select = "select [First Name], [Last Name], Phone from [Data$] where ";
        if (f.vs(firstName))
            select += "[First Name] like \"%" + firstName + "%\" and ";
        if (f.vs(lastName))
            select += "[Last Name] like \"%" + lastName + "%\" and ";
        if (f.vs(category))
            select += "[Category] = \"" + category + "\" and ";
        select = select.Substring(0, select.Length - 4); // Lose the terminal "and "

        // This makes the SQL case-insensitive! BUT IT CAUSES ExecuteReader() FAIL
        // select += " [COLLATE SQL_Latin1_General_CP1_CI_AS]";

        // Build the connect string, using the specified Excel address file
        string connectionString =
            "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +
            @excelAddressFile +
            ";Extended Properties=Excel 8.0;";

        // Get a DB connection from an OLE DB provider factory
        DbProviderFactory factory = DbProviderFactories.GetFactory("System.Data.OleDb");
        using (DbConnection connection = factory.CreateConnection())
        {

            // Assign the connection string
            connection.ConnectionString = connectionString;

            // Create the DB command
            using (DbCommand command = connection.CreateCommand())
            {
                // Apply the select
                command.CommandText = select;

                // Retrieve the data -- THIS ExecuteReader() IS WHERE IT FAILS
                using (DbDataReader dr = command.ExecuteReader())
                {
                    while (dr.Read())
                    {

if (f.vs(firstName))
    select += "UCase([First Name]) like \"%" + firstName.ToUpper() + "%\" and ";
if (f.vs(lastName))
    select += "UCase([Last Name]) like \"%" + lastName.ToUpper() + "%\" and ";