Vah*_*hid 5 .net c# oledb datareader oledbconnection
OleDb我使用下面的代码通过连接来连接到 Access 数据库C# .Net
我如何知道硬编码到程序中的表是否确实存在于文件中,以便我可以向用户显示适当的消息?
try
{
var dbSource = "Data Source = " + source;
const string dbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;";
using (var con = new OleDbConnection())
{
con.ConnectionString = dbProvider + dbSource;
con.Open();
using (var cmd = new OleDbCommand())
{
cmd.Connection = con;
cmd.CommandText = "SELECT * FROM [Concrete Design Table 1]";
// How do I know the table name is valid? It results in errors when it is not?
// How to prevent it?
using (var dataReader = cmd.ExecuteReader())
{
while (dataReader != null && dataReader.Read())
{
// read the table here
}
}
}
}
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
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您可以使用以下命令获取表列表
var schema = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
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并浏览它们:
foreach (var row in schema.Rows.OfType<DataRow>())
{
string tableName = row.ItemArray[2].ToString();
}
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或检查是否存在:
if (schema.Rows
.OfType<DataRow>()
.Any(r => r.ItemArray[2].ToString().ToLower() == tablename.ToLower()))
{
// table exists
}
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丑陋,我知道。:(