Missing dry-run support (`--empty`)

[baldwicc]

Issue Summary

dbt build model_name --empty executes select * from schema.model_name where false limit 0 statements.

These aren't valid in Synapse/T-SQL and return Incorrect syntax near 'limit'. errors.

Versions

dbt-core v1.8.9
dbt-synapse v1.8.1

Cause

SynapseRelation extends BaseRelation but doesn't override the default adapter's render_limited() class method, causing the above behaviour.

dbt-synapse/dbt/adapters/synapse/synapse_relation.py

Lines 10 to 11 in beedf08

	@dataclass(frozen=True, eq=False, repr=False)
	class SynapseRelation(BaseRelation):

Possible fix

dbt-fabric has implemented a render_limited() class method that should work for Synapse as well

    @classmethod
    # from https://github.com/microsoft/dbt-fabric/blob/525fe95c960beb3c8dc0b34130111d6284aa3eab/dbt/adapters/fabric/fabric_relation.py#L20
    def render_limited(self) -> str:
        rendered = self.render()
        if self.limit is None:
            return rendered
        elif self.limit == 0:
            return f"(select * from {rendered} where 1=0) {self._render_limited_alias()}"
        else:
            return f"(select TOP {self.limit} * from {rendered}) {self._render_limited_alias()}"

[alittlesliceoftom]

Hey Chris Baldwin (@baldwicc) , verified and repeated this behaviour.