protected override IEnumerable <Command> OnCreate(IMetadata sourceMetadata, IMetadata targetMetadata, IComparerContext context)
{
if (IsUserCreatedIndex)
{
var command = new Command();
command
.Append($"CREATE {(Unique ? "UNIQUE " : string.Empty)}{(Descending ? "DESCENDING" : "ASCENDING")} INDEX {IndexName.AsSqlIndentifier()}")
.AppendLine()
.Append($" ON {RelationName.AsSqlIndentifier()}");
if (ExpressionSource == null)
{
command.Append($"({string.Join(",", Segments.Select(s => s.FieldName.AsSqlIndentifier()))})");
}
else
{
command.Append($" COMPUTED BY {ExpressionSource}");
}
yield return(command);
if (Inactive)
{
yield return(HandleIndexActiveInactive(context));
}
}
}
private Command HandleIndexActiveInactive(IComparerContext context)
{
return(new Command()
.Append($"ALTER INDEX {IndexName.AsSqlIndentifier()} {(Inactive ? "INACTIVE" : "ACTIVE")}"));
}
private string AddConstraintUsingIndex(IMetadata sourceMetadata, IMetadata targetMetadata, IComparerContext context)
{
var builder = new StringBuilder();
if (RelationConstraintType == RelationConstraintType.PrimaryKey || RelationConstraintType == RelationConstraintType.ForeignKey || RelationConstraintType == RelationConstraintType.Unique)
{
if (ConstraintName != IndexName && !SqlHelper.HasSystemPrefix(IndexName) || Index.Descending)
{
builder
.AppendLine()
.Append($" USING {(Index.Descending ? "DESCENDING" : "ASCENDING")} INDEX {IndexName.AsSqlIndentifier()}");
}
}
return(builder.ToString());
}