bug fix for db2 v10 new column def of syscat.columns.default

lib/Doctrine/DBAL/Platforms/DB2Platform.php

@@ -234,7 +234,7 @@ class DB2Platform extends AbstractPlatform
     }
 
     /**
-     * This code fragment is originally from the Zend_Db_Adapter_Db2 class.
+     * This code fragment is originally from the Zend_Db_Adapter_Db2 class, but has been edited.
      *
      * @license New BSD License
      *
@@ -245,22 +245,47 @@ class DB2Platform extends AbstractPlatform
      */
     public function getListTableColumnsSQL($table, $database = null)
     {
-        return "SELECT DISTINCT c.tabschema, c.tabname, c.colname, c.colno,
-                c.typename, c.default, c.nulls, c.length, c.scale,
-                c.identity, tc.type AS tabconsttype, k.colseq,
-                CASE
-                    WHEN c.generated = 'D' THEN 1
-                    ELSE 0
-                END AS autoincrement
-                FROM syscat.columns c
-                LEFT JOIN (syscat.keycoluse k JOIN syscat.tabconst tc
-                ON (k.tabschema = tc.tabschema
-                    AND k.tabname = tc.tabname
-                    AND tc.type = 'P'))
-                ON (c.tabschema = k.tabschema
-                    AND c.tabname = k.tabname
-                    AND c.colname = k.colname)
-                WHERE UPPER(c.tabname) = UPPER('" . $table . "') ORDER BY c.colno";
+        // We do the funky subquery and join syscat.columns.default this crazy way because
+        // as of db2 v10, the column is CLOB(64k) and the distinct operator won't allow a CLOB,
+        // it wants shorter stuff like a varchar.
+        return "
+        SELECT
+          cols.default,
+          subq.*
+        FROM (
+               SELECT DISTINCT
+                 c.tabschema,
+                 c.tabname,
+                 c.colname,
+                 c.colno,
+                 c.typename,
+                 c.nulls,
+                 c.length,
+                 c.scale,
+                 c.identity,
+                 tc.type AS tabconsttype,
+                 k.colseq,
+                 CASE
+                 WHEN c.generated = 'D' THEN 1
+                 ELSE 0
+                 END     AS autoincrement
+               FROM syscat.columns c
+                 LEFT JOIN (syscat.keycoluse k JOIN syscat.tabconst tc
+                     ON (k.tabschema = tc.tabschema
+                         AND k.tabname = tc.tabname
+                         AND tc.type = 'P'))
+                   ON (c.tabschema = k.tabschema
+                       AND c.tabname = k.tabname
+                       AND c.colname = k.colname)
+               WHERE UPPER(c.tabname) = UPPER('" . $table . "')
+               ORDER BY c.colno
+             ) subq
+          JOIN syscat.columns cols
+            ON subq.tabschema = cols.tabschema
+               AND subq.tabname = cols.tabname
+               AND subq.colno = cols.colno
+        ORDER BY subq.colno
+        ";
     }
 
     /**

tests/Doctrine/Tests/DBAL/Platforms/DoctrineDb2v10AdaptorTest.php

+<?php
+
+
+class DoctrineDb2v10AdaptorTest extends PHPUnit_Framework_TestCase {
+    // The only difference this query has compared to the original is that
+    // I cast the column named "DEFAULT" to varchar(254). I don't feel this will
+    // affect the ability of the DISTINCT clause from doing it's job properly, because
+    // I don't feel we would ever have any rows which only differ in the value of that column.
+    // I had to do this to get it to run on db2 v10.
+    private $oldSql = "
+        SELECT DISTINCT
+          c.tabschema,
+          c.tabname,
+          c.colname,
+          c.colno,
+          c.typename,
+          CAST(c.default AS VARCHAR(254)) AS DEFAULT,
+          c.nulls,
+          c.length,
+          c.scale,
+          c.identity,
+          tc.type                         AS tabconsttype,
+          k.colseq,
+          CASE
+          WHEN c.generated = 'D' THEN 1
+          ELSE 0
+          END                             AS autoincrement
+        FROM syscat.columns c
+          LEFT JOIN (syscat.keycoluse k JOIN syscat.tabconst tc
+              ON (k.tabschema = tc.tabschema
+                  AND k.tabname = tc.tabname
+                  AND tc.type = 'P'))
+            ON (c.tabschema = k.tabschema
+                AND c.tabname = k.tabname
+                AND c.colname = k.colname)
+        WHERE UPPER(c.tabname) = UPPER(?)
+        ORDER BY c.colno
+";
+
+    // This query wraps the original query into a subquery, but omits the column named "DEFAULT".
+    // This way the distinct clause can operate on the remaining columns without error, and then we join the
+    // results back to the syscat.columns table in order to attach the values of the column we omitted.
+    private $newSql = "
+        SELECT
+          cols.default,
+          subq.*
+        FROM (
+               SELECT DISTINCT
+                 c.tabschema,
+                 c.tabname,
+                 c.colname,
+                 c.colno,
+                 c.typename,
+                 c.nulls,
+                 c.length,
+                 c.scale,
+                 c.identity,
+                 tc.type AS tabconsttype,
+                 k.colseq,
+                 CASE
+                 WHEN c.generated = 'D' THEN 1
+                 ELSE 0
+                 END     AS autoincrement
+               FROM syscat.columns c
+                 LEFT JOIN (syscat.keycoluse k JOIN syscat.tabconst tc
+                     ON (k.tabschema = tc.tabschema
+                         AND k.tabname = tc.tabname
+                         AND tc.type = 'P'))
+                   ON (c.tabschema = k.tabschema
+                       AND c.tabname = k.tabname
+                       AND c.colname = k.colname)
+               WHERE UPPER(c.tabname) = UPPER(?)
+               ORDER BY c.colno
+             ) subq
+          JOIN syscat.columns cols
+            ON subq.tabschema = cols.tabschema
+               AND subq.tabname = cols.tabname
+               AND subq.colno = cols.colno
+        ORDER BY subq.colno
+";
+
+    private $conn;
+
+    function setUp()
+    {
+        $config = require '../../config/autoload/global.php';
+        extract($config['doctrine']['connection']['orm_default']['params']);
+        $this->conn = db2_connect("DRIVER={IBM DB2 ODBC DRIVER};HOSTNAME=$host;PORT=$port;DATABASE=$dbname;PROTOCOL=TCPIP;UID=$user;PWD=$password;", $user, $password);
+    }
+
+    function testQueriesProduceIdenticalRowsForAllTables()
+    {
+        foreach ($this->getAllTables() as $tbl) {
+            $this->checkRowsMatchForTable($tbl);
+        }
+    }
+
+    private function checkRowsMatchForTable($tbl)
+    {
+        // run each query and fetch the rows they produce
+        $oldRows = $this->fetchall($this->oldSql, [$tbl], $this->conn);
+        $newRows = $this->fetchall($this->newSql, [$tbl], $this->conn);
+
+        // compare the num of rows
+        $this->assertEquals(count($oldRows), count($newRows));
+
+        // sort them so that I can compare the correct rows
+        $cmp = function($a, $b) {
+            $fmt = "%s,%s,%s";
+            return strcmp(
+                sprintf($fmt, $a['TABSCHEMA'], $a['TABNAME'], $a['COLNO']),
+                sprintf($fmt, $b['TABSCHEMA'], $b['TABNAME'], $b['COLNO'])
+            );
+        };
+        usort($oldRows, $cmp);
+        usort($newRows, $cmp);
+
+        // compare the keys and values of row n in the old to row n in the new.
+        // this doesn't consider the order of the columns in the row, which shouldn't matter.
+        foreach ($oldRows as $k => $oldRow) {
+            $diff = array_diff_assoc($oldRow, $newRows[$k]);
+            if ($diff) {
+                var_dump($k, $diff);
+                print_r($oldRow);
+                print_r($newRows[$k]);
+                print_r($oldRows);
+                print_r($newRows);
+            }
+            $this->assertEmpty($diff);
+        }
+    }
+
+    private function getAllTables()
+    {
+        $sql = "
+        select distinct TABNAME
+        from syscat.columns
+        ";
+
+        return array_map(function($row) {
+            return $row['TABNAME'];
+        }, $this->fetchAll($sql, [], $this->conn));
+    }
+
+    private function fetchAll($sql, $args, $conn)
+    {
+        $ret = [];
+        $stmt = db2_prepare($conn, $sql);
+        db2_execute($stmt, $args);
+        while ($row = db2_fetch_assoc($stmt)) {
+            $ret[] = $row;
+        }
+        return $ret;
+    }
+}
+ 
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