private Ast.ImportColumn ParseImportColumn(TokenQueue q)
{
var n = new Ast.ImportColumn {
SourceToken = q.SourceToken
};
Check(q, n.ColumnName = ParseIdentifierOrExpr(q));
if (q.Peek() == "as")
{
q.Take("as");
n.AsName = Check(q, ParseIdentifierOrExpr(q));
}
switch (q.Peek())
{
case "text": q.Take(); n.TypeConversion = Ast.TypeConversion.Text; break;
case "integer": q.Take(); n.TypeConversion = Ast.TypeConversion.Integer; break;
case "real": q.Take(); n.TypeConversion = Ast.TypeConversion.Real; break;
case "date": q.Take(); n.TypeConversion = Ast.TypeConversion.Date; break;
case "datetime": q.Take(); n.TypeConversion = Ast.TypeConversion.DateTime; break;
case "datetimeoffset": q.Take(); n.TypeConversion = Ast.TypeConversion.DateTimeOffset; break;
}
return(n);
}
public static void GetDestinationColumns(IEnumerable <Ast.ImportColumn> importColumns, ScriptRunner runner,
ScriptEnv env, IReadOnlyList <string> srcColNames, out Ast.ImportColumn[] dstColNodes,
out string[] dstColNames)
{
// if there is no column list specified, then all columns are imported with default settings.
if (!importColumns.Any())
{
importColumns =
srcColNames.Select(x => new Ast.ImportColumn {
ColumnName = new Ast.IdentifierOrExpr {
Identifier = x
},
TypeConversion = Ast.TypeConversion.Text
}).ToList();
}
var lowercaseSrcColNames = srcColNames.Select(x => x.ToLower()).ToArray();
var lowercaseDstColNames = new HashSet <string>(); // to ensure we don't have duplicate column names
dstColNodes = new Ast.ImportColumn[srcColNames.Count];
dstColNames = new string[srcColNames.Count];
foreach (var importCol in importColumns)
{
var name = runner.EvaluateIdentifierOrExpr(importCol.ColumnName, env);
var colIndex = lowercaseSrcColNames.IndexOf(name.ToLower());
if (colIndex.HasValue)
{
if (dstColNodes[colIndex.Value] == null)
{
dstColNodes[colIndex.Value] = importCol;
}
else
{
throw new Exception($"The input column \"{name}\" was specified more than once in the column list.");
}
}
else
{
// the user specified a column name that does not exist in the CSV file
throw new Exception($"The column \"{name}\" does not exist in the CSV file. " +
$"The columns that were found are: {string.Join(", ", srcColNames.Select(DoubleQuote))}");
}
// apply the user's rename if specified
string dstName;
if (importCol.AsName != null)
{
dstName = runner.EvaluateIdentifierOrExpr(importCol.AsName, env);
}
else
{
dstName = name;
}
dstColNames[colIndex.Value] = dstName;
// ensure this isn't a duplicate destination column name
if (lowercaseDstColNames.Contains(dstName.ToLower()))
{
throw new Exception($"The column \"{dstName}\" was specified more than once as a destination column name.");
}
else
{
lowercaseDstColNames.Add(dstName.ToLower());
}
}
}