kevinhinterlong / CalciteUnionError

Example of union error

CalciteUnionError

Attempt to union using

RelBuilder

builder.pushAll(Arrays.asList(first, second))
        .union(true);
String generatedSql = toSql(builder.build(), connection);

Manual

String manualSql = "(" + toSql(second, connection) + ")";
manualSql += "\nUNION ALL\n";
manualSql += "(" + toSql(first, connection) + ")";

The tests

Without ORDER BY AND LIMIT

[SUCCESS] Manual:

(SELECT * 
FROM "PUBLIC"."TEST")

UNION ALL

(SELECT * 
FROM "PUBLIC"."TEST")

[SUCCESS] Using RelBuilder:

SELECT * FROM (
  SELECT * FROM "PUBLIC"."TEST"
  
  UNION ALL
  
  SELECT * FROM "PUBLIC"."TEST"
)

With ORDER BY AND LIMIT

[SUCCESS] Manual:

(SELECT *
FROM "PUBLIC"."TEST"
ORDER BY "TEST_VALUE" NULLS LAST
OFFSET 10 ROWS
FETCH NEXT 20 ROWS ONLY)

UNION ALL

(SELECT *
FROM "PUBLIC"."TEST"
ORDER BY "TEST_VALUE" NULLS LAST
FETCH NEXT 10 ROWS ONLY)

[FAILED] Using RelBuilder:

SELECT * FROM (
    SELECT *
    FROM "PUBLIC"."TEST"
    ORDER BY "TEST_VALUE" NULLS LAST
    FETCH NEXT 10 ROWS ONLY
    
    UNION ALL

    SELECT *
    FROM "PUBLIC"."TEST"
    ORDER BY "TEST_VALUE" NULLS LAST
    OFFSET 10 ROWS
    FETCH NEXT 20 ROWS ONLY
)