Set operators

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Depending on context, USoft partly supports standard SQL set operator syntax, as follows. For details on syntax, semantics and nesting, consult any online SQL tutorial.

USoft is likely to send set operators to the RDBMS for evaluation. This may affect performance. Use Profiler in USoft Benchmark to find out whether evaluation is client-side or RDBMS-side, and to measure the performance penalty.

 

SQL Command

Logical View SQL

Constraint SQL, main statement

Constraint SQL, subqueries

UNION

Yes

No

No

Yes

UNION ALL

Yes

Yes

No

Yes

MINUS

Yes

No

No

Yes

INTERSECT

Yes

No

No

Yes

 

 

collapseUNION
collapseUNION ALL
collapseMINUS
collapseINTERSECT

 

 

See also

Queries and subqueries

Join constructs

DML statements

Table aliases

Transaction control statements

Method invocation statements