public override DataTable GetColumns()
{
var dataTable = SchemaTables.GetColumnsDataTable();
// There is no way to get the scale of a decimal with DAO. Looks like someone at Microsoft just forgot to
// implement it.
// Therefore, either ADO has to be used, or DAO together with the GetSchema()
// method (that contains precision and scale, but no default value when using ODBC, because again, looks
// like someone at Microsoft just forgot to implement it).
Dictionary <(string TableName, string ColumnName), int?> numericScales = null;
if (!_naturalOnly)
{
var schemaTable = _connection.InnerConnection.GetSchema("Columns");
numericScales = schemaTable.Rows
.Cast <DataRow>()
.ToDictionary(
t => (TableName: (string)t["TABLE_NAME"], ColumnName: (string)t["COLUMN_NAME"]),
t => t.Table.Columns.Contains("DECIMAL_DIGITS")
? t["DECIMAL_DIGITS"] != DBNull.Value
? (int?)(short?)t["DECIMAL_DIGITS"]
: null
: t["NUMERIC_SCALE"] != DBNull.Value
? (int?)(short?)t["NUMERIC_SCALE"]
: null);
}
var objectDefsCollection = new[]
public override DataTable GetColumns()
{
var dataTable = SchemaTables.GetColumnsDataTable();
// There is no way to get the ordinal position of a column with ADOX. Looks like someone at Microsoft just forgot to
// implement it.
// Therefore, either DAO has to be used, or ADOX together with the OpenSchema()
// method.
Dictionary <(string TableName, string ColumnName), int> ordinalPositions = null;
if (!_naturalOnly)
{
using (var recordset = _connection.OpenSchema(SchemaEnum.adSchemaColumns))
{
ordinalPositions = new Dictionary <(string TableName, string ColumnName), int>();
using var fields = recordset.Fields;
using var tableNameField = fields["TABLE_NAME"];
using var columnNameField = fields["COLUMN_NAME"];
using var ordinalPositionField = fields["ORDINAL_POSITION"];
recordset.MoveFirst();
while (!recordset.EOF)
{
var tableName = (string)tableNameField.Value;
var columnName = (string)columnNameField.Value;
var ordinalPosition = (int)ordinalPositionField.Value - 1;
ordinalPositions.Add((tableName, columnName), ordinalPosition);
recordset.MoveNext();
}
recordset.Close();
}
}
using var tables = _catalog.Tables;
var tableCount = tables.Count;
for (var i = 0; i < tableCount; i++)
{
using var table = tables[i];
var tableName = (string)table.Name;
using var columns = table.Columns;
var columnCount = columns.Count;
for (var j = 0; j < columnCount; j++)
{
using var column = columns[j];
using var properties = column.Properties;
var columnName = (string)column.Name;
var attributes = (ColumnAttributesEnum)column.Attributes;
var ordinalPosition = ordinalPositions?[(tableName, columnName)] ?? j;