/// <summary>
/// Visits the given <paramref name="alterTableNode"/>.
/// </summary>
/// <param name="alterTableNode"></param>
public override void Visit(IAlterTableNode alterTableNode)
{
ITableDefinition table = Environment.Schema.GetTable(alterTableNode.Name);
foreach(IAstNode node in alterTableNode.ChildNodes)
{
if(node is IRemoveColumnNode)
table.RemoveColumn(((IRemoveColumnNode)node).Name);
else if(node is IAddColumnNode)
{
IAddColumnNode addColumnNode = (IAddColumnNode)node;
table.AddColumn(BindAddColumn(addColumnNode));
addColumnNode.Table = table.Name;
} // else
else if(node is IAlterColumnNode)
{
IColumnDefinition columnDefinition = table.GetColumn(((IAlterColumnNode)node).Name);
IColumnNode columnNode = (IColumnNode)node;
columnNode.Type = columnDefinition.Type;
columnNode.Length = columnDefinition.Length;
BindColumnProperties(columnNode, columnDefinition);
AlterColumn(columnDefinition, (IAlterColumnNode)node);
} // else if
node.Accept(this);
} // foreach
}
/// <summary>
/// Visits the given <paramref name="alterTableNode"/>.
/// </summary>
/// <param name="alterTableNode"></param>
public override void Visit(IAlterTableNode alterTableNode)
{
Visit(alterTableNode.ChildNodes);
}
/// <summary>
/// Visits the given <paramref name="alterTableNode" />.
/// </summary>
/// <param name="alterTableNode"></param>
public override void Visit(IAlterTableNode alterTableNode)
{
textWriter.Write("alter table {0}", GetIdentifier(alterTableNode.Name));
WriteProperties(alterTableNode);
VisitBlock(alterTableNode);
}
public override void Visit(IAlterTableNode alterTableNode)
{
IncludeTemplates(alterTableNode);
}
protected override void AlterTableAlterColumn(IAlterTableNode alterTableNode, IAlterColumnNode alterColumnNode)
{
}
protected override void AlterTableRemoveColumn(IAlterTableNode alterTableNode, IRemoveColumnNode removeColumnNode)
{
}
protected virtual void AlterTableRemoveColumn(IAlterTableNode alterTableNode, IRemoveColumnNode removeColumnNode)
{
TextWriter.WriteLine("alter table {0} drop column {1};",
Platform.Dialect.EscapeIdentifier(alterTableNode.Name),
Platform.Dialect.EscapeIdentifier(removeColumnNode.Name));
}
protected virtual void AlterTableAlterColumn(IAlterTableNode alterTableNode, IAlterColumnNode alterColumnNode)
{
TextWriter.WriteLine("alter table {0} alter column {1};",
Platform.Dialect.EscapeIdentifier(alterTableNode.Name),
GetAlterColumnDefinition(alterColumnNode));
}
public override void Visit(IAlterTableNode alterTableNode)
{
foreach(IAstNode astNode in alterTableNode.ChildNodes)
{
if(astNode is IAddColumnNode)
{
//
// Here's the situation: when downgrading, we potentially may encounter
// a situation when we restore a previously deleted column. If table
// in question contains data and column being added is non-nullable,
// we won't be able to do so. To circumvent this problem, enforce
// column to be nullable.
var addColumnNode = (IAddColumnNode)astNode;
TextWriter.WriteLine("alter table {0} add {1};",
Platform.Dialect.EscapeIdentifier(alterTableNode.Name),
GetColumnDefinition(addColumnNode, alterTableNode.Parent is IDowngradeNode));
} // if
if(astNode is IRemoveColumnNode)
{
var removeColumnNode = (IRemoveColumnNode)astNode;
AlterTableRemoveColumn(alterTableNode, removeColumnNode);
} // if
if(astNode is IAlterColumnNode)
{
var alterColumnNode = (IAlterColumnNode)astNode;
AlterTableAlterColumn(alterTableNode, alterColumnNode);
} // if
} // foreach
}
