[SCHEMA] Better DBMS information fetching

On PostgreSQL:
  - Parse defaults for strings and booleans properly.
  - Parse the "serial" definition type properly.
  - Get information on the "enum" definition type.
  - Re-work getting information about keys/indices.

On MariaDB:
  - Get information about lengths in indices.
  - Get foreign key information separately from the rest as they can have
    colliding names.

lib/database/mysqlschema.php

@@ -157,50 +157,37 @@ class MysqlSchema extends Schema
         }
 
         if ($hasKeys) {
-            // INFORMATION_SCHEMA's CONSTRAINTS and KEY_COLUMN_USAGE tables give
+            $key_info = $this->fetchKeyInfo($table);
-            // good info on primary and unique keys but don't list ANY info on
-            // multi-value keys, which is lame-o. Sigh.
-            $keyColumns = $this->fetchMetaInfo($table, 'KEY_COLUMN_USAGE', 'CONSTRAINT_NAME, ORDINAL_POSITION');
-            $keys = [];
-            $fkeys = [];
 
-            foreach ($keyColumns as $row) {
+            foreach ($key_info as $row) {
-                $keyName = $row['CONSTRAINT_NAME'];
+                $key_name = $row['key_name'];
-                $keyCol = $row['COLUMN_NAME'];
-                if (!isset($keys[$keyName])) {
-                    $keys[$keyName] = [];
-                }
-                $keys[$keyName][] = $keyCol;
-                if (!is_null($row['REFERENCED_TABLE_NAME'])) {
-                    $fkeys[] = $keyName;
-                }
-            }
-
-            foreach ($keys as $keyName => $cols) {
-                if ($keyName === 'PRIMARY') {
-                    $def['primary key'] = $cols;
-                } elseif (in_array($keyName, $fkeys)) {
-                    $fkey = $this->fetchForeignKeyInfo($table, $keyName);
-                    $colMap = array_combine($cols, $fkey['cols']);
-                    $def['foreign keys'][$keyName] = [$fkey['table_name'], $colMap];
-                } else {
-                    $def['unique keys'][$keyName] = $cols;
-                }
-            }
-
-            $indexInfo = $this->fetchIndexInfo($table);
-
-            foreach ($indexInfo as $row) {
-                $keyName = $row['key_name'];
                 $cols = $row['cols'];
 
-                if ($row['key_type'] === 'FULLTEXT') {
+                switch ($row['key_type']) {
-                    $def['fulltext indexes'][$keyName] = $cols;
+                    case 'PRIMARY':
-                } else {
+                        $def['primary key'] = $cols;
-                    $def['indexes'][$keyName] = $cols;
+                        break;
+                    case 'UNIQUE':
+                        $def['unique keys'][$key_name] = $cols;
+                        break;
+                    case 'FULLTEXT':
+                        $def['fulltext indexes'][$key_name] = $cols;
+                        break;
+                    default:
+                        $def['indexes'][$key_name] = $cols;
                 }
             }
         }
+
+        $foreign_key_info = $this->fetchForeignKeyInfo($table);
+
+        foreach ($foreign_key_info as $row) {
+            $key_name = $row['key_name'];
+            $cols = $row['cols'];
+            $ref_table = $row['ref_table'];
+
+            $def['foreign keys'][$key_name] = [$ref_table, $cols];
+        }
         return $def;
     }
 
@@ -235,14 +222,17 @@ class MysqlSchema extends Schema
      */
     public function fetchMetaInfo($table, $infoTable, $orderBy = null)
     {
-        $query = "SELECT * FROM INFORMATION_SCHEMA.%s " .
-            "WHERE TABLE_SCHEMA='%s' AND TABLE_NAME='%s'";
         $schema = $this->conn->dsn['database'];
-        $sql = sprintf($query, $infoTable, $schema, $table);
+        return $this->fetchQueryData(sprintf(
-        if ($orderBy) {
+            <<<'END'
-            $sql .= ' ORDER BY ' . $orderBy;
+            SELECT * FROM INFORMATION_SCHEMA.%1$s
-        }
+              WHERE TABLE_SCHEMA = '%2$s' AND TABLE_NAME = '%3$s'%4$s;
-        return $this->fetchQueryData($sql);
+            END,
+            $this->quoteIdentifier($infoTable),
+            $schema,
+            $table,
+            ($orderBy ? " ORDER BY {$orderBy}" : '')
+        ));
     }
 
     /**
@@ -252,64 +242,89 @@ class MysqlSchema extends Schema
      * @return array of arrays
      * @throws PEAR_Exception
      */
-    public function fetchIndexInfo(string $table): array
+    private function fetchKeyInfo(string $table): array
+    {
+        $schema = $this->conn->dsn['database'];
+        $data = $this->fetchQueryData(
+            <<<EOT
+            SELECT INDEX_NAME AS `key_name`,
+                CASE
+                  WHEN INDEX_NAME = 'PRIMARY' THEN 'PRIMARY'
+                  WHEN NON_UNIQUE IS NOT TRUE THEN 'UNIQUE'
+                  ELSE INDEX_TYPE
+                END AS `key_type`,
+                COLUMN_NAME AS `col`,
+                SUB_PART AS `col_length`
+              FROM INFORMATION_SCHEMA.STATISTICS
+              WHERE TABLE_SCHEMA = '{$schema}' AND TABLE_NAME = '{$table}'
+              ORDER BY `key_name`, `key_type`, SEQ_IN_INDEX;
+            EOT
+        );
+
+        $rows = [];
+        foreach ($data as $row) {
+            $name = $row['key_name'];
+
+            if (!is_null($row['col_length'])) {
+                $row['col'] = [$row['col'], (int) $row['col_length']];
+            }
+            unset($row['col_length']);
+
+            if (!array_key_exists($name, $rows)) {
+                $row['cols'] = [$row['col']];
+
+                unset($row['col']);
+                $rows[$name] = $row;
+            } else {
+                $rows[$name]['cols'][] = $row['col'];
+            }
+        }
+
+        return array_values($rows);
+    }
+
+    /**
+     * Pull foreign key information for the given table.
+     *
+     * @param string $table
+     * @return array array of arrays
+     * @throws PEAR_Exception
+     */
+    private function fetchForeignKeyInfo(string $table): array
     {
         $schema = $this->conn->dsn['database'];
         $data = $this->fetchQueryData(
             <<<END
-            SELECT INDEX_NAME AS `key_name`, INDEX_TYPE AS `key_type`, COLUMN_NAME AS `col`
+            SELECT CONSTRAINT_NAME AS `key_name`,
-              FROM INFORMATION_SCHEMA.STATISTICS
+                COLUMN_NAME AS `col`,
+                REFERENCED_TABLE_NAME AS `ref_table`,
+                REFERENCED_COLUMN_NAME AS `ref_col`
+              FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
               WHERE TABLE_SCHEMA = '{$schema}'
               AND TABLE_NAME = '{$table}'
-              AND NON_UNIQUE IS TRUE
+              AND REFERENCED_TABLE_SCHEMA = '{$schema}'
-              ORDER BY SEQ_IN_INDEX;
+              ORDER BY `key_name`, ORDINAL_POSITION;
             END
         );
 
         $rows = [];
         foreach ($data as $row) {
             $name = $row['key_name'];
-            if (isset($rows[$name])) {
+
-                $rows[$name]['cols'][] = $row['col'];
+            if (!array_key_exists($name, $rows)) {
-            } else {
+                $row['cols'] = [$row['col'] => $row['ref_col']];
-                $row['cols'] = [$row['col']];
+
                 unset($row['col']);
+                unset($row['ref_col']);
                 $rows[$name] = $row;
+            } else {
+                $rows[$name]['cols'][$row['col']] = $row['ref_col'];
             }
         }
+
         return array_values($rows);
     }
 
-    /**
-     * @param string $table
-     * @param string $constraint_name
-     * @return array array of rows with keys: table_name, cols (array of strings)
-     * @throws PEAR_Exception
-     */
-    public function fetchForeignKeyInfo(string $table, string $constraint_name): array
-    {
-        $query = 'SELECT REFERENCED_TABLE_NAME AS `table_name`, REFERENCED_COLUMN_NAME AS `col` ' .
-            'FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE ' .
-            'WHERE TABLE_SCHEMA = \'%s\' AND TABLE_NAME = \'%s\' AND CONSTRAINT_NAME = \'%s\' ' .
-            'AND REFERENCED_TABLE_SCHEMA IS NOT NULL ' .
-            'ORDER BY POSITION_IN_UNIQUE_CONSTRAINT';
-        $schema = $this->conn->dsn['database'];
-        $sql = sprintf($query, $schema, $table, $constraint_name);
-        $data = $this->fetchQueryData($sql);
-        if (count($data) < 1) {
-            throw new Exception('Could not find foreign key ' . $constraint_name . ' on table ' . $table);
-        }
-
-        $info = [
-            'table_name' => $data[0]['table_name'],
-            'cols'       => [],
-        ];
-        foreach ($data as $row) {
-            $info['cols'][] = $row['col'];
-        }
-        return $info;
-    }
-
     /**
      * Append an SQL statement with an index definition for a full-text search
      * index over one or more columns on a table.

lib/database/pgsqlschema.php

@@ -80,12 +80,11 @@ class PgsqlSchema extends Schema
             throw new SchemaTableMissingException("No such table: $table");
         }
 
-        // We'll need to match up fields by ordinal reference
+        // Get information on the emulated "enum" type
-        $orderedFields = [];
+        $enum_info = $this->fetchEnumInfo($table);
 
         foreach ($columns as $row) {
             $name = $row['column_name'];
-            $orderedFields[$row['ordinal_position']] = $name;
 
             $field = [];
             $field['type'] = $type = $row['udt_name'];
@@ -108,68 +107,66 @@ class PgsqlSchema extends Schema
             if ($row['is_nullable'] == 'NO') {
                 $field['not null'] = true;
             }
-            if ($row['column_default'] !== null) {
+            $col_default = $row['column_default'];
-                $field['default'] = $row['column_default'];
+            if (!is_null($col_default)) {
                 if ($this->isNumericType($field)) {
-                    $field['default'] = (int) $field['default'];
+                    $field['default'] = (int) $col_default;
+                } elseif ($type === 'bool') {
+                    $field['default'] = ($col_default === 'true') ? true : false;
+                } else {
+                    $match = "/^'(.*)'(::.+)*$/";
+                    if (preg_match($match, $col_default)) {
+                        $field['default'] = preg_replace(
+                            $match,
+                            '\1',
+                            $col_default
+                        );
+                    } else {
+                        $field['default'] = $col_default;
                     }
                 }
+            }
+            if (
+                $row['is_identity'] === 'YES'
+                && $row['identity_generation'] = 'BY DEFAULT'
+            ) {
+                $field['auto_increment'] = true;
+            } elseif (array_key_exists($name, $enum_info)) {
+                $field['type'] = $type = 'enum';
+                $field['enum'] = $enum_info[$name];
+            }
 
             $def['fields'][$name] = $field;
         }
 
-        // Pulling index info from pg_class & pg_index
+        $key_info = $this->fetchKeyInfo($table);
-        // This can give us primary & unique key info, but not foreign key constraints
-        // so we exclude them and pick them up later.
-        $indexInfo = $this->fetchIndexInfo($table);
 
-        foreach ($indexInfo as $row) {
+        foreach ($key_info as $row) {
-            $keyName = $row['key_name'];
+            $key_name = $row['key_name'];
+            $cols = $row['cols'];
 
-            // Dig the column references out!
+            switch ($row['key_type']) {
-            //
+                case 'primary':
-            // These are inconvenient arrays with partial references to the
-            // pg_att table, but since we've already fetched up the column
-            // info on the current table, we can look those up locally.
-            $cols = [];
-            $colPositions = explode(' ', $row['indkey']);
-            foreach ($colPositions as $ord) {
-                if ($ord == 0) {
-                    $cols[] = 'FUNCTION'; // @fixme
-                } else {
-                    $cols[] = $orderedFields[$ord];
-                }
-            }
-
-            $def['indexes'][$keyName] = $cols;
-        }
-
-        // Pull constraint data from INFORMATION_SCHEMA:
-        // Primary key, unique keys, foreign keys
-        $keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position');
-        $keys = [];
-
-        foreach ($keyColumns as $row) {
-            $keyName = $row['constraint_name'];
-            $keyCol = $row['column_name'];
-            if (!isset($keys[$keyName])) {
-                $keys[$keyName] = [];
-            }
-            $keys[$keyName][] = $keyCol;
-        }
-
-        foreach ($keys as $keyName => $cols) {
-            // name hack -- is this reliable?
-            if ($keyName == "{$table}_pkey") {
                     $def['primary key'] = $cols;
-            } elseif (preg_match("/^{$table}_(.*)_fkey$/", $keyName, $matches)) {
+                    break;
-                $fkey = $this->fetchForeignKeyInfo($table, $keyName);
+                case 'unique':
-                $colMap = array_combine($cols, $fkey['col_names']);
+                    $def['unique keys'][$key_name] = $cols;
-                $def['foreign keys'][$keyName] = [$fkey['table_name'], $colMap];
+                    break;
-            } else {
+                default:
-                $def['unique keys'][$keyName] = $cols;
+                    $def['indexes'][$key_name] = $cols;
             }
         }
+
+        $foreign_key_info = $this->fetchForeignKeyInfo($table);
+
+        foreach ($foreign_key_info as $row) {
+            $key_name = $row['key_name'];
+            $cols = $row['cols'];
+            $ref_table = $row['ref_table'];
+
+            $def['foreign keys'][$key_name] = [$ref_table, $cols];
+        }
+
         return $def;
     }
 
@@ -184,90 +181,158 @@ class PgsqlSchema extends Schema
      */
     public function fetchMetaInfo($table, $infoTable, $orderBy = null)
     {
-        $query = "SELECT * FROM information_schema.%s " .
+        $catalog = $this->conn->dsn['database'];
-            "WHERE table_name='%s'";
+        return $this->fetchQueryData(sprintf(
-        $sql = sprintf($query, $infoTable, $table);
+            <<<'END'
-        if ($orderBy) {
+            SELECT * FROM information_schema.%1$s
-            $sql .= ' ORDER BY ' . $orderBy;
+              WHERE table_catalog = '%2$s' AND table_name = '%3$s'%4$s;
-        }
+            END,
-        return $this->fetchQueryData($sql);
+            $this->quoteIdentifier($infoTable),
+            $catalog,
+            $table,
+            ($orderBy ? " ORDER BY {$orderBy}" : '')
+        ));
     }
 
     /**
-     * Pull some PG-specific index info
+     * Pull index and keys information for the given table.
+     *
      * @param string $table
      * @return array of arrays
      * @throws PEAR_Exception
      */
-    public function fetchIndexInfo(string $table): array
+    private function fetchKeyInfo(string $table): array
     {
-        return $this->fetchQueryData(
+        $data = $this->fetchQueryData(sprintf(
+            <<<'EOT'
+            SELECT "rel"."relname" AS "key_name",
+                CASE
+                  WHEN "idx"."indisprimary" IS TRUE THEN 'primary'
+                  WHEN "idx"."indisunique"  IS TRUE THEN 'unique'
+                  ELSE "am"."amname"
+                END AS "key_type",
+                "cols"."attname" AS "col"
+              FROM pg_index AS "idx"
+              CROSS JOIN LATERAL unnest("idx"."indkey")
+              WITH ORDINALITY AS "col_nums" ("num", "pos")
+              INNER JOIN pg_class AS "rel"
+              ON "idx"."indexrelid" = "rel".oid
+              LEFT JOIN pg_attribute AS "cols"
+              ON "idx"."indrelid" = "cols"."attrelid"
+              AND "col_nums"."num" = "cols"."attnum"
+              LEFT JOIN pg_am AS "am"
+              ON "rel"."relam" = "am".oid
+              WHERE "idx"."indrelid" = CAST('%s' AS REGCLASS)
+              ORDER BY "key_type", "key_name", "col_nums"."pos";
+            EOT,
+            $table
+        ));
+
+        $rows = [];
+        foreach ($data as $row) {
+            $name = $row['key_name'];
+
+            if (!array_key_exists($name, $rows)) {
+                $row['cols'] = [$row['col']];
+
+                unset($row['col']);
+                $rows[$name] = $row;
+            } else {
+                $rows[$name]['cols'][] = $row['col'];
+            }
+        }
+
+        return array_values($rows);
+    }
+
+    /**
+     * Pull foreign key information for the given table.
+     *
+     * @param string $table
+     * @return array array of arrays
+     * @throws PEAR_Exception
+     */
+    private function fetchForeignKeyInfo(string $table): array
+    {
+        $data = $this->fetchQueryData(sprintf(
+            <<<'END'
+            SELECT "con"."conname" AS "key_name",
+                "cols"."attname" AS "col",
+                "ref_rel"."relname" AS "ref_table",
+                "ref_cols"."attname" AS "ref_col"
+              FROM pg_constraint AS "con"
+              CROSS JOIN LATERAL unnest("con"."conkey", "con"."confkey")
+              WITH ORDINALITY AS "col_nums" ("num", "ref_num", "pos")
+              LEFT JOIN pg_attribute AS "cols"
+              ON "con"."conrelid" = "cols"."attrelid"
+              AND "col_nums"."num" = "cols"."attnum"
+              LEFT JOIN pg_class AS "ref_rel"
+              ON "con"."confrelid" = "ref_rel".oid
+              LEFT JOIN pg_attribute AS "ref_cols"
+              ON "con"."confrelid" = "ref_cols"."attrelid"
+              AND "col_nums"."ref_num" = "ref_cols"."attnum"
+              WHERE "con"."contype" = 'f'
+              AND "con"."conrelid" = CAST('%s' AS REGCLASS)
+              ORDER BY "key_name", "col_nums"."pos";
+            END,
+            $table
+        ));
+
+        $rows = [];
+        foreach ($data as $row) {
+            $name = $row['key_name'];
+
+            if (!array_key_exists($name, $rows)) {
+                $row['cols'] = [$row['col'] => $row['ref_col']];
+
+                unset($row['col']);
+                unset($row['ref_col']);
+                $rows[$name] = $row;
+            } else {
+                $rows[$name]['cols'][$row['col']] = $row['ref_col'];
+            }
+        }
+
+        return array_values($rows);
+    }
+
+    /**
+     * Pull information about the emulated enum columns
+     *
+     * @param string $table
+     * @return array of arrays
+     * @throws PEAR_Exception
+     */
+    private function fetchEnumInfo($table)
+    {
+        $data = $this->fetchQueryData(
             <<<END
-            SELECT indexname AS key_name, indexdef AS key_def, pg_index.*
+            SELECT "cols"."attname" AS "col", "con"."consrc" AS "check"
-              FROM pg_index INNER JOIN pg_indexes
+              FROM pg_constraint AS "con"
-              ON pg_index.indexrelid = CAST(pg_indexes.indexname AS regclass)
+              INNER JOIN pg_attribute AS "cols"
-              WHERE pg_indexes.tablename = '{$table}'
+              ON "con"."conrelid" = "cols"."attrelid"
-              AND indisprimary IS FALSE AND indisunique IS FALSE
+              AND "con"."conkey"[1] = "cols"."attnum"
-              ORDER BY indrelid, indexrelid;
+              WHERE "cols".atttypid = CAST('text' AS REGTYPE)
+              AND "con"."contype" = 'c'
+              AND cardinality("con"."conkey") = 1
+              AND "con"."conrelid" = CAST('{$table}' AS REGCLASS);
             END
         );
-    }
 
-    /**
+        $rows = [];
-     * @param string $table
-     * @param string $constraint_name
-     * @return array array of rows with keys: table_name, col_names (array of strings)
-     * @throws PEAR_Exception
-     */
-    public function fetchForeignKeyInfo(string $table, string $constraint_name): array
-    {
-        // In a sane world, it'd be easier to query the column names directly.
-        // But it's pretty hard to work with arrays such as col_indexes in direct SQL here.
-        $query = 'SELECT ' .
-            '(SELECT relname FROM pg_class WHERE oid = confrelid) AS table_name, ' .
-            'confrelid AS table_id, ' .
-            '(SELECT indkey FROM pg_index WHERE indexrelid = conindid) AS col_indices ' .
-            'FROM pg_constraint ' .
-            'WHERE conrelid = CAST(\'%s\' AS regclass) AND conname = \'%s\' AND contype = \'f\'';
-        $sql = sprintf($query, $table, $constraint_name);
-        $data = $this->fetchQueryData($sql);
-        if (count($data) < 1) {
-            throw new Exception('Could not find foreign key ' . $constraint_name . ' on table ' . $table);
-        }
-
-        $row = $data[0];
-        return [
-            'table_name' => $row['table_name'],
-            'col_names' => $this->getTableColumnNames($row['table_id'], $row['col_indices'])
-        ];
-    }
-
-    /**
-     *
-     * @param int $table_id
-     * @param array $col_indexes
-     * @return array of strings
-     * @throws PEAR_Exception
-     */
-    public function getTableColumnNames($table_id, $col_indexes)
-    {
-        $indexes = array_map('intval', explode(' ', $col_indexes));
-        $query = 'SELECT attnum AS col_index, attname AS col_name ' .
-            'FROM pg_attribute where attrelid=%d ' .
-            'AND attnum IN (%s)';
-        $sql = sprintf($query, $table_id, implode(',', $indexes));
-        $data = $this->fetchQueryData($sql);
-
-        $byId = [];
         foreach ($data as $row) {
-            $byId[$row['col_index']] = $row['col_name'];
+            // PostgreSQL can show either
-        }
+            $name_regex = '(' . preg_quote($this->quoteIdentifier($row['col']))
+                        . '|' . preg_quote($row['col']) . ')';
 
-        $out = [];
+            $enum = explode("'::text, '", preg_replace(
-        foreach ($indexes as $id) {
+                "/^\({$name_regex} = ANY \(ARRAY\['(.+)'::text]\)\)$/D",
-            $out[] = $byId[$id];
+                '\2',
+                $row['check']
+            ));
+            $rows[$row['col']] = $enum;
         }
-        return $out;
+        return $rows;
     }
 
     private function isNumericType(array $cd): bool
@@ -293,16 +358,6 @@ class PgsqlSchema extends Schema
         $line = [];
         $line[] = parent::columnSql($name, $cd);
 
-        /*
-        if ($table['foreign keys'][$name]) {
-            foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) {
-                $line[] = 'references';
-                $line[] = $this->quoteIdentifier($foreignTable);
-                $line[] = '(' . $this->quoteIdentifier($foreignColumn) . ')';
-            }
-        }
-        */
-
         // This'll have been added from our transform of 'serial' type
         if (!empty($cd['auto_increment'])) {
             $line[] = 'GENERATED BY DEFAULT AS IDENTITY';
@@ -328,8 +383,7 @@ class PgsqlSchema extends Schema
             'integer'  => 'int',
             'char'     => 'bpchar',
             'datetime' => 'timestamp',
-            'blob'     => 'bytea',
+            'blob'     => 'bytea'
-            'enum'     => 'text',
         ];
 
         $type = $column['type'];