public static IEnumerable <string> GetColumnNames(ExcelQueryArgs args)
{
var con = GetConnection(args);
var res = new List <string>();
try
{
if (con.State == System.Data.ConnectionState.Closed)
{
con.Open();
}
using (var cmd = con.CreateCommand())
{
cmd.CommandText = $"SELECT TOP 1 * FROM [{args.SheetName}$]";
var data = cmd.ExecuteReader();
var scheme = data?.GetSchemaTable();
foreach (DataRow item in scheme.Rows)
{
res.Add(item["ColumnName"].ToString());
}
}
return(res);
}
finally
{
con.Dispose();
}
}
public ExcelQueryModelVisitor(ExcelQueryArgs args)
{
this.args = args;
this.Builder = new SqlBuilder();
if (args.SheetName != null)
{
this.Builder.SheetName = args.SheetName + "$";
}
else
{
this.Builder.SheetName = "Sheet1$";
}
}
public ExcelQueryExecutor(ExcelQueryArgs args)
{
this.visitor = new ExcelQueryModelVisitor(args);
this.args = args;
}
public WhereClauseExpressionTree(ExcelQueryArgs args)
{
this.args = args;
this.listParams = new List <OleDbParameter>();
this.whereClause.Append("WHERE ");
}
public ExcelFactory(string filename)
{
this.args = new ExcelQueryArgs {
FileName = filename
};
}
public static OleDbConnection GetConnection(ExcelQueryArgs args)
{
var connString = CreateConnectionString(args.FileName);
return(new OleDbConnection(connString));
}
private static IQueryExecutor CreateExecutor(ExcelQueryArgs args)
{
return(new ExcelQueryExecutor(args));
}
public ExcelQuery(ExcelQueryArgs args) :
base(CreateExecutor(args))
{
}
