Issue #401: NPE in "SELECT DISTINCT * ORDER BY"

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #401: NPE in "SELECT DISTINCT * ORDER BY"
+</li>
 <li>Added BITGET function
 </li>
 <li>Fixed bug in FilePathRetryOnInterrupt that caused infinite loop

h2/src/main/org/h2/result/ResultTempTable.java

@@ -7,7 +7,6 @@ package org.h2.result;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-
 import org.h2.command.ddl.CreateTableData;
 import org.h2.engine.Constants;
 import org.h2.engine.Database;
@@ -88,7 +87,9 @@ public class ResultTempTable implements ResultExternal {
 
     private void createIndex() {
         IndexColumn[] indexCols = null;
-        if (sort != null) {
+        // If we need to do distinct, the distinct columns may not match the sort columns
+        // so we need to disregard the sort. Not ideal.
+        if (sort != null && !distinct) {
             int[] colIndex = sort.getQueryColumnIndexes();
             indexCols = new IndexColumn[colIndex.length];
             for (int i = 0; i < colIndex.length; i++) {

h2/src/main/org/h2/table/IndexColumn.java

@@ -74,4 +74,9 @@ public class IndexColumn {
             col.column = table.getColumn(col.columnName);
         }
     }
+
+    @Override
+    public String toString() {
+        return "IndexColumn " + getSQL();
+    }
 }

h2/src/test/org/h2/test/db/TestTempTables.java

@@ -10,7 +10,6 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
-
 import org.h2.api.ErrorCode;
 import org.h2.engine.Constants;
 import org.h2.store.fs.FileUtils;
@@ -48,6 +47,7 @@ public class TestTempTables extends TestBase {
         c1.close();
         c2.close();
         testLotsOfTables();
+        testCreateAsSelectDistinct();
         deleteDb("tempTables");
     }
 
@@ -333,4 +333,24 @@ public class TestTempTables extends TestBase {
         }
         conn.close();
     }
+
+    /**
+     * Issue #401: NPE in "SELECT DISTINCT * ORDER BY"
+     */
+    private void testCreateAsSelectDistinct() throws SQLException {
+        deleteDb("tempTables");
+        Connection conn = getConnection("tempTables;MAX_MEMORY_ROWS=1000");
+        Statement stat = conn.createStatement();
+        stat.execute("CREATE TABLE ONE(S1 VARCHAR(255), S2 VARCHAR(255))");
+        PreparedStatement prep = conn
+                .prepareStatement("insert into one values(?,?)");
+        for (int row = 0; row < 10000; row++) {
+            prep.setString(1, "abc");
+            prep.setString(2, "def" + row);
+            prep.execute();
+        }
+        stat.execute(
+                "CREATE TABLE TWO AS SELECT DISTINCT * FROM ONE ORDER BY S1");
+        conn.close();
+    }
 }