public void Execute(DatabaseTable baseTable, DatabaseTable compareTable)
{
//find new columns (in compare, but not in base)
foreach (var column in compareTable.Columns)
{
var name = column.Name;
var match = baseTable.Columns.FirstOrDefault(t => t.Name == name);
if (match != null)
{
continue;
}
var script = "-- ADDED TABLE " + column.TableName + " COLUMN " + name + Environment.NewLine +
_writer.AddColumn(compareTable, column);
CreateResult(ResultType.Add, baseTable, name, script);
}
//find dropped and existing columns
foreach (var column in baseTable.Columns)
{
var name = column.Name;
var match = compareTable.Columns.FirstOrDefault(t => t.Name == name);
if (match == null)
{
CreateResult(ResultType.Delete, baseTable, name,
_writer.DropColumn(baseTable, column));
continue;
}
//has column changed?
if (string.Equals(column.DbDataType, match.DbDataType, StringComparison.OrdinalIgnoreCase) &&
column.Length == match.Length &&
column.Precision == match.Precision &&
column.Scale == match.Scale &&
column.Nullable == match.Nullable)
{
//we don't check IDENTITY
continue; //the same, no action
}
CreateResult(ResultType.Change, baseTable, name,
_writer.AlterColumn(baseTable, match, column));
}
}
public void Execute(DatabaseTable baseTable, DatabaseTable compareTable)
{
//find new columns (in compare, but not in base)
foreach (var column in compareTable.Columns)
{
var name = column.Name;
var match = baseTable.Columns.FirstOrDefault(t => t.Name == name);
if (match != null)
{
continue;
}
_sb.AppendLine("-- ADDED TABLE " + column.TableName + " COLUMN " + name);
_sb.AppendLine(_writer.AddColumn(compareTable, column));
}
//find dropped and existing columns
foreach (var column in baseTable.Columns)
{
var name = column.Name;
var match = compareTable.Columns.FirstOrDefault(t => t.Name == name);
if (match == null)
{
_sb.AppendLine(_writer.DropColumn(baseTable, column));
continue;
}
//has column changed?
if (column.DbDataType == match.DbDataType &&
column.Length == match.Length &&
column.Precision == match.Precision &&
column.Scale == match.Scale &&
column.Nullable == match.Nullable)
{
//we don't check IDENTITY
continue; //the same, no action
}
_sb.AppendLine(_writer.AlterColumn(baseTable, match, column));
}
}
public void Execute(DatabaseTable baseTable, DatabaseTable compareTable)
{
//find new columns (in compare, but not in base)
var copy = baseTable.Clone();
foreach (var column in compareTable.Columns)
{
var name = column.Name;
var match = baseTable.Columns.FirstOrDefault(t => t.Name == name);
if (match != null)
{
continue;
}
var script = "-- ADDED TABLE " + column.TableName + " COLUMN " + name + Environment.NewLine +
_writer.AddColumn(compareTable, column);
copy.AddColumn(column);
CreateResult(ResultType.Add, baseTable, name, script);
}
//find dropped and existing columns
var toDrop = new Dictionary <string, DatabaseColumn>();
var toAlter = new Dictionary <string, DatabaseColumn[]>();
foreach (var column in baseTable.Columns)
{
var name = column.Name;
var match = compareTable.Columns.FirstOrDefault(t => t.Name == name);
if (match == null)
{
toDrop.Add(name, column);
continue;
}
//has column changed?
if (string.Equals(column.DbDataType, match.DbDataType, StringComparison.OrdinalIgnoreCase) &&
column.Length == match.Length &&
column.Precision == match.Precision &&
column.Scale == match.Scale &&
column.Nullable == match.Nullable)
{
//we don't check IDENTITY
continue; //the same, no action
}
toAlter.Add(name, new[] { match, column });
}
//write drops and alters as last step to ensure valid queries
foreach (var kv in toAlter)
{
copy.Columns.Remove(kv.Value[1]);
copy.Columns.Add(kv.Value[0]);
CreateResult(ResultType.Change, baseTable, kv.Key,
_writer.AlterColumn(copy, kv.Value[0], kv.Value[1]));
}
foreach (var kv in toDrop)
{
copy.Columns.Remove(kv.Value);
CreateResult(ResultType.Delete, baseTable, kv.Key,
_writer.DropColumn(copy, kv.Value));
continue;
}
}
