Deny adding a not null column in Redshift connector

Author: ebyhr

plugin/trino-redshift/src/main/java/io/trino/plugin/redshift/RedshiftClient.java

@@ -38,6 +38,7 @@
 import io.trino.plugin.jdbc.ObjectWriteFunction;
 import io.trino.plugin.jdbc.PreparedQuery;
 import io.trino.plugin.jdbc.QueryBuilder;
+import io.trino.plugin.jdbc.RemoteTableName;
 import io.trino.plugin.jdbc.SliceWriteFunction;
 import io.trino.plugin.jdbc.StandardColumnMappings;
 import io.trino.plugin.jdbc.WriteMapping;
@@ -58,6 +59,7 @@
 import io.trino.spi.TrinoException;
 import io.trino.spi.connector.AggregateFunction;
 import io.trino.spi.connector.ColumnHandle;
+import io.trino.spi.connector.ColumnMetadata;
 import io.trino.spi.connector.ConnectorSession;
 import io.trino.spi.connector.JoinCondition;
 import io.trino.spi.connector.JoinStatistics;
@@ -442,6 +444,17 @@ public OptionalLong delete(ConnectorSession session, JdbcTableHandle handle)
         }
     }
 
+    @Override
+    protected void addColumn(ConnectorSession session, Connection connection, RemoteTableName table, ColumnMetadata column)
+            throws SQLException
+    {
+        if (!column.isNullable()) {
+            // Redshift doesn't support adding not null columns without default expression
+            throw new TrinoException(NOT_SUPPORTED, "This connector does not support adding not null columns");
+        }
+        super.addColumn(session, connection, table, column);
+    }
+
     @Override
     protected void verifySchemaName(DatabaseMetaData databaseMetadata, String schemaName)
             throws SQLException

plugin/trino-redshift/src/test/java/io/trino/plugin/redshift/TestRedshiftConnectorTest.java

@@ -76,6 +76,7 @@ protected boolean hasBehavior(TestingConnectorBehavior connectorBehavior)
                 return false;
 
             case SUPPORTS_ADD_COLUMN_WITH_COMMENT:
+            case SUPPORTS_ADD_COLUMN_NOT_NULL_CONSTRAINT:
             case SUPPORTS_SET_COLUMN_TYPE:
                 return false;
 
@@ -198,6 +199,15 @@ public Object[][] redshiftTypeToTrinoTypes()
                 {"TIMESTAMPTZ", "timestamp(6) with time zone"}};
     }
 
+    @Test
+    public void testRedshiftAddNotNullColumn()
+    {
+        try (TestTable table = new TestTable(getQueryRunner()::execute, TEST_SCHEMA + ".test_add_column_", "(col int)")) {
+            assertThatThrownBy(() -> onRemoteDatabase().execute("ALTER TABLE " + table.getName() + " ADD COLUMN new_col int NOT NULL"))
+                    .hasMessageContaining("ERROR: ALTER TABLE ADD COLUMN defined as NOT NULL must have a non-null default expression");
+        }
+    }
+
     @Override
     public void testDelete()
     {