public override IEnumerable <string> SqlCommands(IDbConnection connection)
{
foreach (var cmd in base.SqlCommands(connection))
{
yield return(cmd);
}
CreateTable ct = new CreateTable(_modelType);
string pkName;
bool inPK = ct.InPrimaryKey(_columnRef.ColumnName, out pkName) || connection.IsColumnInPrimaryKey(_columnRef, out pkName);
if (inPK)
{
yield return($"ALTER TABLE [{_columnRef.Schema}].[{_columnRef.TableName}] DROP CONSTRAINT [{pkName}]");
}
ForeignKeyRef fk;
if (_columnRef.IsForeignKey(connection, out fk))
{
yield return($"ALTER TABLE [{_columnRef.Schema}].[{_columnRef.TableName}] DROP CONSTRAINT [{fk.ConstraintName}]");
}
yield return($"ALTER TABLE [{_columnRef.Schema}].[{_columnRef.TableName}] DROP COLUMN [{_columnRef.ColumnName}]");
if (inPK)
{
yield return($"ALTER TABLE [{_columnRef.Schema}].[{_columnRef.TableName}] ADD {ct.CreateTablePrimaryKey(ct.GetClusterAttribute())}");
}
}
//private readonly IEnumerable<ForeignKeyRef> _foreignKeys; you won't be dropping the key usually, so there's really no need to drop dependent FKs
internal DropColumn(ColumnRef columnRef, IDbConnection connection) : base(MergeObjectType.Column, MergeActionType.Delete, columnRef.ToString())
{
_columnRef = columnRef;
ForeignKeyRef fk;
if (columnRef.IsForeignKey(connection, out fk))
{
_dropFK = fk;
}
//_foreignKeys = GetReferencingForeignKeys(connection, columnRef.ObjectID);
_cn = connection;
}