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Appender fix UNION has members after STRUCT (1.5) #563

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Merged
staticlibs merged 1 commit into from
Feb 9, 2026
Merged

Appender fix UNION has members after STRUCT (1.5) #563

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19 changes: 8 additions & 11 deletions src/main/java/org/duckdb/DuckDBAppender.java
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Original file line number Diff line number Diff line change
Expand Up @@ -985,7 +985,13 @@ private Column nextColumn(Column curCol) {
if (null == curCol.parent) {
cols = columns;
} else {
cols = curCol.parent.children;
if (DUCKDB_TYPE_UNION == curCol.parent.colType) {
curCol = curCol.parent;
// recurse up the union
return nextColumn(curCol);
} else {
cols = curCol.parent.children;
}
}
int nextColIdx = curCol.idx + 1;
if (nextColIdx < cols.size()) {
Expand All @@ -1004,11 +1010,7 @@ private Column nextColumn(Column curCol) {
private void moveToNextColumn() throws SQLException {
Column col = currentColumn();
this.prevColumn = currentColumn;
if (unionBegunInvariant()) {
this.currentColumn = nextColumn(col.parent);
} else {
this.currentColumn = nextColumn(col);
}
this.currentColumn = nextColumn(col);
}

// checks
Expand Down Expand Up @@ -2127,11 +2129,6 @@ private boolean structCompletedInvariant() {
prevColumn.idx == prevColumn.parent.children.size() - 1;
}

private boolean unionBegunInvariant() {
return null != currentColumn && null != currentColumn.parent &&
currentColumn.parent.colType == DUCKDB_TYPE_UNION;
}

private boolean unionCompletedInvariant() {
return null != prevColumn && null != prevColumn.parent && prevColumn.parent.colType == DUCKDB_TYPE_UNION;
}
Expand Down
107 changes: 107 additions & 0 deletions src/test/java/org/duckdb/TestAppenderComposite.java
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Original file line number Diff line number Diff line change
Expand Up @@ -480,6 +480,113 @@ public static void test_appender_union_nested() throws Exception {
}
}

public static void test_appender_union_struct() throws Exception {
try (DuckDBConnection conn = DriverManager.getConnection(JDBC_URL).unwrap(DuckDBConnection.class);
Statement stmt = conn.createStatement()) {
stmt.execute("CREATE TABLE tab1 ("
+ "col1 INTEGER, "
+ "col2 UNION("
+ " u1 STRUCT("
+ " s1 INTEGER, "
+ " s2 INTEGER"
+ " ), "
+ " u2 INTEGER"
+ " )"
+ ")");

try (DuckDBAppender appender = conn.createAppender("tab1")) {
appender.beginRow()
.append(42)
.beginUnion("u1")
.beginStruct()
.append(43)
.append(44)
.endStruct()
.endUnion()
.endRow()

.beginRow()
.append(45)
.beginUnion("u2")
.append(46)
.endUnion()
.endRow()

.beginRow()
.append(47)
.beginUnion("u1")
.appendNull()
.endUnion()
.endRow()

.beginRow()
.append(48)
.beginUnion("u2")
.appendNull()
.endUnion()
.endRow()

.beginRow()
.append(49)
.appendNull()
.endRow()

.beginRow()
.append(50)
.beginUnion("u1")
.beginStruct()
.append(51)
.append(52)
.endStruct()
.endUnion()
.endRow();
}

try (ResultSet rs = stmt.executeQuery("SELECT * FROM tab1 ORDER BY col1")) {
{
assertTrue(rs.next());
assertEquals(rs.getInt(1), 42);
DuckDBStruct struct = (DuckDBStruct) rs.getObject(2);
Map<String, Object> map = struct.getMap();
assertEquals(map.size(), 2);
assertEquals(map.get("s1"), 43);
assertEquals(map.get("s2"), 44);
}

assertTrue(rs.next());
assertEquals(rs.getInt(1), 45);
assertEquals(rs.getInt(2), 46);

assertTrue(rs.next());
assertEquals(rs.getInt(1), 47);
assertNull(rs.getObject(2));
assertFalse(rs.wasNull());

assertTrue(rs.next());
assertEquals(rs.getInt(1), 48);
assertNull(rs.getObject(2));
assertFalse(rs.wasNull());

assertTrue(rs.next());
assertEquals(rs.getInt(1), 49);
assertNull(rs.getObject(2));
assertTrue(rs.wasNull());

{
assertTrue(rs.next());
assertEquals(rs.getInt(1), 50);
DuckDBStruct struct = (DuckDBStruct) rs.getObject(2);
Map<String, Object> map = struct.getMap();
assertEquals(map.size(), 2);
assertEquals(map.get("s1"), 51);
assertEquals(map.get("s2"), 52);
}

assertFalse(rs.next());
}
}
}

private static void assertFetchedStructEquals(Object dbs, Collection<Object> struct) throws Exception {
DuckDBStruct dbStruct = (DuckDBStruct) dbs;
Map<String, Object> map = dbStruct.getMap();
Expand Down