此 SELECT 按预期找到 Kelly:
选择 [First Name]、[Last Name]、Phone from [Data$] where [First Name] like "%Kelly%"
在 Excel 电子表格中,名字是大写“K”的“Kelly”——SELECT 还指定了大写“K”。
但是,如果 > 中的 K 像 "%Kelly%" < 是小写的——比如 "%kelly%"——那么就找不到记录。SELECT 区分大小写。
SQL Server 似乎没有可以应用于数据库列的 lower() 或 lcase() 方法(???!!!)。这是真的吗?网络上的广泛建议是将“COLLATE SQL_Latin1_General_CP1_CI_AS”附加到 SQL 语句,执行 ExecuteReader() 时会产生错误“IErrorInfo.GetDescription failed 0x80004005”。
有人可以建议一种方法让我的 SQL SELECT 对 Excel 不区分大小写吗?
我已经粘贴了下面的代码。
(f.vs() 方法在传递一个有效字符串时返回 true,即 IsEmptyOrNull() 为 false 的字符串。)
TIA - 霍伊斯特
// The user may specify the first or last names, or category, or // any combination, possibly all three.
// Build the select; [Data$] 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())
{