/// <summary>
/// This sub creates a given <see cref="DASDataTable"></see> object with the schema information found for the given
/// table.
/// </summary>
/// <param name="columnList">String with a comma separated list of all columns.</param>
/// <param name="tableName">Name of the database table which schema should be used.</param>
/// <exception cref="ArgumentNullException"></exception>
/// <remarks>
/// <para>
/// You can use the column list to select the needed columns. You can also rename the database column by using
/// aliases in the list.
/// </para>
/// <para>
/// To use aliases just name them like in normal sql. For example
/// <quote>column1 as mycolumn1, column2 as mycolumn2</quote>.
/// </para>
/// </remarks>
/// <exception cref="NotConnectedException">Thrown when there is no established connection.</exception>
public DASDataTable CreateDASDataTable(string columnList, string tableName)
{
if ((string.IsNullOrEmpty(columnList)))
{
throw new ArgumentNullException(nameof(columnList));
}
if ((string.IsNullOrEmpty(tableName)))
{
throw new ArgumentNullException(nameof(tableName));
}
if (IsConnected)
{
var dataTable = new DASDataTable(this);
var cmd = _providerFactory.CreateCommand();
cmd.CommandText = $"SELECT {columnList} FROM {tableName}";
cmd.Connection = Connection;
cmd.Transaction = _transaction;
dataTable.Load(cmd.ExecuteReader(CommandBehavior.SchemaOnly));
var dasDataTable = new DASDataTable(this);
foreach (DataColumn column in dataTable.Columns)
{
var dasColumn = new DASDataColumn
{
ColumnName = column.ColumnName,
DBColumnName = column.ColumnName,
DataType = column.DataType,
MaxLength = column.MaxLength,
AllowDBNull = column.AllowDBNull,
Unique = column.Unique
};
dasDataTable.Columns.Add(dasColumn);
}
var keys = new DASDataColumn[dataTable.PrimaryKey.Length + 1];
var i = 0;
foreach (var column in dataTable.PrimaryKey)
{
keys[i] = dasDataTable.Columns.ItemByName(column.ColumnName);
i += 1;
}
dasDataTable.PrimaryKey = keys;
dasDataTable.DBTableName = tableName;
dasDataTable.BuildAndSetBaseSQL();
return(dasDataTable);
}
throw new NotConnectedException();
}
/// <summary>
/// This function checks whether a column exists.
/// </summary>
/// <param name="Column"><see cref=" DASDataColumn "></see> to be checked.</param>
/// <returns><c>True</c>, if column is part of the columns collection.</returns>
public bool ContainsColumn(DASDataColumn Column)
{
return(m_Columns.Contains(Column.ColumnName));
}
/// <summary>
/// This sub adds the given column to the collection.
/// </summary>
/// <param name="Column"><see cref=" DASDataColumn "></see> object to be added.</param>
public void Add(DASDataColumn Column)
{
m_Columns.Add(Column);
}
/// <summary>
/// This sub removes the given column from the collection.
/// </summary>
/// <param name="Column"><see cref=" DASDataColumn "></see> object to be removed.</param>
public void Remove(DASDataColumn Column)
{
m_Columns.Remove(Column);
}
/// <summary>
/// This is the constructor of the class.
/// </summary>
/// <param name="Row"><see cref=" DASDataRow "></see> object needed for initialization.</param>
/// <param name="Column"><see cref=" DASDataColumn "></see> object needed for initialization.</param>
public DASColumnValue(DASDataRow Row, DASDataColumn Column)
{
_row = Row;
_column = Column;
}