Rezoom.SQL.Plans

This namespace contains extension methods to run SQL commands as Rezoom plans.

Simple execution

This extension creates a plan that will run the given command and return its result directly.

static member Plan : cmd : Command<'a> -> Plan<'a>

Taking the only result

If you execute a query with a limit 1 clause, you will probably not want to deal with the list of rows you get back. You'll only care about the first returned row, and you might want to assert that there aren't more rows just as a sanity check. These methods do that. Both will throw if the result list contains more than one object. The TryExactlyOne variant will accept empty lists and return None, while the ExactlyOne variant will throw on empty lists.

static member TryExactlyOne : cmd : Command<#IReadOnlyList<'a>> -> Plan<'a option>
static member ExactlyOne : command : Command<#IReadOnlyList<'a>> -> Plan<'a>

Note that it is not necessary to use these methods when RZSQL can statically infer that a query will always return exactly one row. For example, if you execute a simple select 1 as x, 2 as y; with no where or limit clause, that will always produce a single row, so RZSQL will generate the command type as Command<Query.Row> instead of Command<IReadOnlyList<Query.Row>>.

Processing scalar results

When a generated row type has only one column, it will get an automatic implementation of IScalar<TypeOfColumn>. This allows you to use this extension method for convenient handling of single-row, single-column queries like select rowcount() as x;.

static member Scalar : cmd : Command<#IScalar<'a>> -> Plan<'a>