public override async Task <DataTable> GetSchemaTableAsync(CancellationToken cancellationToken = default)
#endif
{
CheckState();
if (_schemaTable != null)
{
return(_schemaTable);
}
DataRow schemaRow = null;
var tableCount = 0;
var currentTable = string.Empty;
_schemaTable = GetSchemaTableStructure();
/* Prepare statement for schema fields information */
var schemaCmd = new FbCommand(GetSchemaCommandText(), _command.Connection, _command.Connection.InnerConnection.ActiveTransaction);
try
{
schemaCmd.Parameters.Add("@TABLE_NAME", FbDbType.Char, 31);
schemaCmd.Parameters.Add("@COLUMN_NAME", FbDbType.Char, 31);
await schemaCmd.PrepareAsync(cancellationToken).ConfigureAwait(false);
_schemaTable.BeginLoadData();
for (var i = 0; i < _fields.Count; i++)
{
var isKeyColumn = false;
var isUnique = false;
var isReadOnly = false;
var precision = 0;
var isExpression = false;
/* Get Schema data for the field */
schemaCmd.Parameters[0].Value = _fields[i].Relation;
schemaCmd.Parameters[1].Value = _fields[i].Name;
var reader = await schemaCmd.ExecuteReaderAsync(CommandBehavior.Default, cancellationToken).ConfigureAwait(false);
try
{
if (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
isReadOnly = IsReadOnly(reader) || IsExpression(reader);
isKeyColumn = reader.GetInt32(2) == 1;
isUnique = reader.GetInt32(3) == 1;
precision = reader.IsDBNull(4) ? -1 : reader.GetInt32(4);
isExpression = IsExpression(reader);
}
}
finally
{
#if NET48 || NETSTANDARD2_0
reader.Dispose();
#else
await reader.DisposeAsync().ConfigureAwait(false);
#endif
}
/* Create new row for the Schema Table */
schemaRow = _schemaTable.NewRow();
schemaRow["ColumnName"] = GetName(i);
schemaRow["ColumnOrdinal"] = i;
schemaRow["ColumnSize"] = _fields[i].GetSize();
if (_fields[i].IsDecimal())
{
schemaRow["NumericPrecision"] = schemaRow["ColumnSize"];
if (precision > 0)
{
schemaRow["NumericPrecision"] = precision;
}
schemaRow["NumericScale"] = _fields[i].NumericScale * (-1);
}
schemaRow["DataType"] = GetFieldType(i);
schemaRow["ProviderType"] = GetProviderType(i);
schemaRow["IsLong"] = _fields[i].IsLong();
schemaRow["AllowDBNull"] = _fields[i].AllowDBNull();
schemaRow["IsRowVersion"] = false;
schemaRow["IsAutoIncrement"] = false;
schemaRow["IsReadOnly"] = isReadOnly;
schemaRow["IsKey"] = isKeyColumn;
schemaRow["IsUnique"] = isUnique;
schemaRow["IsAliased"] = _fields[i].IsAliased();
schemaRow["IsExpression"] = isExpression;
schemaRow["BaseSchemaName"] = DBNull.Value;
schemaRow["BaseCatalogName"] = DBNull.Value;
schemaRow["BaseTableName"] = _fields[i].Relation;
schemaRow["BaseColumnName"] = _fields[i].Name;
_schemaTable.Rows.Add(schemaRow);
if (!string.IsNullOrEmpty(_fields[i].Relation) && currentTable != _fields[i].Relation)
{
tableCount++;
currentTable = _fields[i].Relation;
}
await schemaCmd.CloseAsync().ConfigureAwait(false);
}
if (tableCount > 1)
{
foreach (DataRow row in _schemaTable.Rows)
{
row["IsKey"] = false;
row["IsUnique"] = false;
}
}
_schemaTable.EndLoadData();
}
finally
{
#if NET48 || NETSTANDARD2_0
schemaCmd.Dispose();
#else
await schemaCmd.DisposeAsync().ConfigureAwait(false);
#endif
}
return(_schemaTable);
}
