/// <summary>
/// Reads table with Database Objects which satisfy given restriction. Base implementation
/// uses direct SQL query to the INFORMATION_SCHEMA.
/// </summary>
/// <param name="connection">The DataConnectionWrapper to be used for enumeration.</param>
/// <param name="restrictions">The restrictions to be putted on the retrieved objects set.</param>
/// <param name="sort">Sort expresion to append after ORDER BY clause.</param>
/// <returns>Returns table with Database Objects which satisfy given restriction.</returns>
protected override DataTable ReadTable(DataConnectionWrapper connection, object[] restrictions, string sort)
{
if (connection == null)
{
throw new ArgumentNullException("connection");
}
// Extract server version
Version serverVersion = connection.ServerVersion;
// For latest version just return base result
if (serverVersion == null || serverVersion.Major >= 5)
{
return(base.ReadTable(connection, restrictions, sort));
}
// Temporary table to store result
DataTable merged = new DataTable();
// Enumerate all tables
DataTable tables = TableDescriptor.Enumerate(connection, restrictions);
// If there is now tables, return empty table with columns
if (tables == null || tables.Rows == null || tables.Rows.Count <= 0)
{
return(merged);
}
// Calculate column restrriction
object column = restrictions != null && restrictions.Length >= 4 ? restrictions[3] : null;
// Enumerate columns for each table
foreach (DataRow tableRow in tables.Rows)
{
// Enumerate columns
DataTable columns = ReadColumnsForTable(
connection,
new object[] {
null,
DataInterpreter.GetString(tableRow, TableDescriptor.Attributes.Schema),
DataInterpreter.GetString(tableRow, TableDescriptor.Attributes.Name),
column
},
sort);
// Merge results if any
if (columns != null)
{
merged.Merge(columns);
}
}
// Return results
return(merged);
}
/// <summary>
/// Reads table with Database Objects which satisfy given restriction. Uses table enumeration for legacy
/// version.
/// </summary>
/// <param name="connection">The DataConnectionWrapper to be used for enumeration.</param>
/// <param name="restrictions">The restrictions to be putted on the retrieved objects set.</param>
/// <param name="sort">Sort expresion to append after ORDER BY clause.</param>
/// <returns>Returns table with Database Objects which satisfy given restriction.</returns>
protected override DataTable ReadTable(DataConnectionWrapper connection, object[] restrictions, string sort)
{
if (connection == null)
{
throw new ArgumentNullException("connection");
}
// Extract server version
Version serverVersion = connection.ServerVersion;
// For latest version just return base result
if (serverVersion == null || serverVersion.Major >= 5)
{
return(base.ReadTable(connection, restrictions, sort));
}
;
// For legacy version enumerate tables
DataTable result = TableDescriptor.Enumerate(connection, restrictions);
// If result is empty, return it
if (result == null)
{
return(null);
}
// Add is updatable column
result.Columns.Add(Attributes.IsUpdatable, typeof(string));
// Set is updatable to true for each row
foreach (DataRow table in result.Rows)
{
DataInterpreter.SetValueIfChanged(table, Attributes.IsUpdatable, DataInterpreter.True);
}
// Finaly, return result
return(result);
}
