private void EnsureSchemaTable()
{
if (_currentSchemaTable != null || FieldCount == 0)
{
return;
}
var formats = CurrentResultSet?.Formats;
if (formats == null)
{
return;
}
var table = new DataTable("SchemaTable");
var columns = table.Columns;
var columnName = columns.Add(SchemaTableColumn.ColumnName, typeof(string));
var columnOrdinal = columns.Add(SchemaTableColumn.ColumnOrdinal, typeof(int));
var columnSize = columns.Add(SchemaTableColumn.ColumnSize, typeof(int));
var numericPrecision = columns.Add(SchemaTableColumn.NumericPrecision, typeof(int));
var numericScale = columns.Add(SchemaTableColumn.NumericScale, typeof(int));
var isUnique = columns.Add(SchemaTableColumn.IsUnique, typeof(bool));
var isKey = columns.Add(SchemaTableColumn.IsKey, typeof(bool));
var baseServerName = columns.Add(SchemaTableOptionalColumn.BaseServerName, typeof(string));
var baseCatalogName = columns.Add(SchemaTableOptionalColumn.BaseCatalogName, typeof(string));
var baseColumnName = columns.Add(SchemaTableColumn.BaseColumnName, typeof(string));
var baseSchemaName = columns.Add(SchemaTableColumn.BaseSchemaName, typeof(string));
var baseTableName = columns.Add(SchemaTableColumn.BaseTableName, typeof(string));
var dataType = columns.Add(SchemaTableColumn.DataType, typeof(Type));
var allowDBNull = columns.Add(SchemaTableColumn.AllowDBNull, typeof(bool));
var providerType = columns.Add(SchemaTableColumn.ProviderType, typeof(int));
var isAliased = columns.Add(SchemaTableColumn.IsAliased, typeof(bool));
var isExpression = columns.Add(SchemaTableColumn.IsExpression, typeof(bool));
var isIdentity = columns.Add("IsIdentity", typeof(bool));
var isAutoIncrement = columns.Add(SchemaTableOptionalColumn.IsAutoIncrement, typeof(bool));
var isRowVersion = columns.Add(SchemaTableOptionalColumn.IsRowVersion, typeof(bool));
var isHidden = columns.Add(SchemaTableOptionalColumn.IsHidden, typeof(bool));
var isLong = columns.Add(SchemaTableColumn.IsLong, typeof(bool));
var isReadOnly = columns.Add(SchemaTableOptionalColumn.IsReadOnly, typeof(bool));
columns.Add(SchemaTableOptionalColumn.ProviderSpecificDataType, typeof(Type));
var dataTypeName = columns.Add("DataTypeName", typeof(string));
//do we need these?
columns.Add("XmlSchemaCollectionDatabase", typeof(string));
columns.Add("XmlSchemaCollectionOwningSchema", typeof(string));
columns.Add("XmlSchemaCollectionName", typeof(string));
columns.Add("UdtAssemblyQualifiedName");
columns.Add(SchemaTableColumn.NonVersionedProviderType, typeof(int));
//means "is column [a sparse] set", not "is column set [to a value]"
columns.Add("IsColumnSet", typeof(bool));
string baseCatalogNameValue = null;
string baseSchemaNameValue = null;
string baseTableNameValue = null;
for (var i = 0; i < formats.Length; i++)
{
var column = formats[i];
var row = table.NewRow();
var aseDbType = TypeMap.GetAseDbType(column);
row[columnName] = column.DisplayColumnName;
row[columnOrdinal] = i;
row[columnSize] = column.Length ?? -1;
row[numericPrecision] = column.Precision ?? -1;
row[numericScale] = column.Scale ?? -1;
row[isUnique] = false; // This gets set below.
row[isKey] = false; // This gets set below - no idea why TDS_ROW_KEY is never set.
row[baseServerName] = string.Empty;
row[baseCatalogName] = column.CatalogName;
row[baseColumnName] = column.ColumnName;
row[baseSchemaName] = column.SchemaName;
row[baseTableName] = column.TableName;
row[dataType] = TypeMap.GetNetType(column);
row[allowDBNull] = column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_NULLALLOWED);
row[providerType] = aseDbType;
row[isAliased] = !string.IsNullOrWhiteSpace(column.ColumnLabel);
row[isExpression] = false; // It doesn't seem to matter that this isn't supported. The column gets flagged as TDS_ROW_UPDATABLE|TDS_ROW_NULLALLOWED so it doesn't cause an issue when an insert/update ignores it.
row[isIdentity] = column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_IDENTITY);
row[isAutoIncrement] = column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_IDENTITY);
row[isRowVersion] = column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_VERSION);
row[isHidden] = column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_HIDDEN);
row[isLong] = LongTdsTypes.Contains(column.DataType);
row[isReadOnly] = !column.RowStatus.HasFlag(RowFormatItemStatus.TDS_ROW_UPDATABLE);
row[dataTypeName] = $"{aseDbType}";
table.Rows.Add(row);
if (string.IsNullOrEmpty(baseTableNameValue))
{
baseTableNameValue = column.TableName;
baseSchemaNameValue = column.SchemaName;
baseCatalogNameValue = column.CatalogName;
}
}
// Try to load the key info
//if ((_behavior & CommandBehavior.KeyInfo) == CommandBehavior.KeyInfo)
{
if (_command.Connection == null)
{
throw new InvalidOperationException("Invalid AseCommand.Connection");
}
if (_command.Connection.State != ConnectionState.Open)
{
throw new InvalidOperationException("Invalid AseCommand.Connection.ConnectionState");
}
using (var command = _command.Connection.CreateCommand())
{
command.CommandText = $"{baseCatalogNameValue}..sp_oledb_getindexinfo";
command.CommandType = CommandType.StoredProcedure;
var tableName = command.CreateParameter();
tableName.ParameterName = "@table_name";
tableName.AseDbType = AseDbType.VarChar;
tableName.Value = baseTableNameValue;
command.Parameters.Add(tableName);
var tableOwner = command.CreateParameter();
tableOwner.ParameterName = "@table_owner";
tableOwner.AseDbType = AseDbType.VarChar;
tableOwner.Value = baseSchemaNameValue;
command.Parameters.Add(tableOwner);
var tableQualifier = command.CreateParameter();
tableQualifier.ParameterName = "@table_qualifier";
tableQualifier.AseDbType = AseDbType.VarChar;
tableQualifier.Value = baseCatalogNameValue;
command.Parameters.Add(tableQualifier);
try
{
using (var keyInfoDataReader = command.ExecuteReader())
{
while (keyInfoDataReader.Read())
{
var keyColumnName = keyInfoDataReader["COLUMN_NAME"].ToString();
var keySchemaName = keyInfoDataReader["TABLE_SCHEMA"].ToString();
var keyCatalogName = keyInfoDataReader["TABLE_CATALOG"].ToString();
foreach (DataRow row in table.Rows)
{
// Use the base column name in case the column is aliased.
if (
string.Equals(keyColumnName, row[baseColumnName].ToString(),
StringComparison.OrdinalIgnoreCase) &&
string.Equals(keySchemaName, row[baseSchemaName].ToString(),
StringComparison.OrdinalIgnoreCase) &&
string.Equals(keyCatalogName, row[baseCatalogName].ToString(),
StringComparison.OrdinalIgnoreCase))
{
row[isKey] = (bool)keyInfoDataReader["PRIMARY_KEY"];
row[isUnique] = (bool)keyInfoDataReader["UNIQUE"];
}
}
}
}
}
catch
{
// ignored
}
}
}
_currentSchemaTable = table;
}
