/// <summary>
/// Show the columns and column metadata from a specific table.
/// </summary>
/// <param name="tableName">The table to view.</param>
/// <returns>A list of column objects.</returns>
public List <Column> DescribeTable(string tableName)
{
if (String.IsNullOrEmpty(tableName))
{
throw new ArgumentNullException(nameof(tableName));
}
List <Column> columns = new List <Column>();
DataTable result = Query(PostgresqlHelper.LoadTableColumnsQuery(_Settings.DatabaseName, tableName));
if (result != null && result.Rows.Count > 0)
{
foreach (DataRow currColumn in result.Rows)
{
#region Process-Each-Column
/*
* public bool PrimaryKey;
* public string Name;
* public string DataType;
* public int? MaxLength;
* public bool Nullable;
*/
Column tempColumn = new Column();
tempColumn.Name = currColumn["COLUMN_NAME"].ToString();
tempColumn.MaxLength = null;
if (currColumn.Table.Columns.Contains("CHARACTER_MAXIMUM_LENGTH"))
{
int maxLength = 0;
if (Int32.TryParse(currColumn["CHARACTER_MAXIMUM_LENGTH"].ToString(), out maxLength))
{
tempColumn.MaxLength = maxLength;
}
}
tempColumn.Type = Helper.DataTypeFromString(currColumn["DATA_TYPE"].ToString());
if (currColumn.Table.Columns.Contains("IS_NULLABLE"))
{
if (String.Compare(currColumn["IS_NULLABLE"].ToString(), "YES") == 0)
{
tempColumn.Nullable = true;
}
else
{
tempColumn.Nullable = false;
}
}
else if (currColumn.Table.Columns.Contains("IS_NOT_NULLABLE"))
{
tempColumn.Nullable = !(Convert.ToBoolean(currColumn["IS_NOT_NULLABLE"]));
}
if (currColumn["IS_PRIMARY_KEY"] != null &&
currColumn["IS_PRIMARY_KEY"] != DBNull.Value &&
!String.IsNullOrEmpty(currColumn["IS_PRIMARY_KEY"].ToString()))
{
if (currColumn["IS_PRIMARY_KEY"].ToString().ToLower().Equals("yes"))
{
tempColumn.PrimaryKey = true;
}
}
if (!columns.Exists(c => c.Name.Equals(tempColumn.Name)))
{
columns.Add(tempColumn);
}
#endregion
}
}
return(columns);
}
