diff --git a/src/PgSqlCommandResult.php b/src/PgSqlCommandResult.php
index 5b23c08..fe4ce60 100644
--- a/src/PgSqlCommandResult.php
+++ b/src/PgSqlCommandResult.php
@@ -34,6 +34,17 @@ final class PgSqlCommandResult implements CommandResult
     }
 
     /**
+     * @deprecated This is not meant to be used to get the last insertion ID. Use `INSERT ... RETURNING column_name`
+     *             to get the last auto-increment ID.
+     *
+     * $sql = "INSERT INTO person (lastname, firstname) VALUES (?, ?) RETURNING id;"
+     * $statement = yield $pool->prepare($sql);
+     * $result = yield $statement->execute(['Doe', 'John']);
+     * if (!yield $result->advance()) {
+     *     throw new \RuntimeException("Insertion failed");
+     * }
+     * $id = $result->getCurrent()['id'];
+     *
      * @return string
      */
     public function getLastOid(): string
diff --git a/src/PgSqlHandle.php b/src/PgSqlHandle.php
index de135d3..2dc6939 100644
--- a/src/PgSqlHandle.php
+++ b/src/PgSqlHandle.php
@@ -241,13 +241,14 @@ final class PgSqlHandle implements Handle
 
     /**
      * @param resource $result PostgreSQL result resource.
+     * @param string $sql Query SQL.
      *
      * @return \Amp\Sql\CommandResult|ResultSet
      *
      * @throws FailureException
      * @throws QueryError
      */
-    private function createResult($result)
+    private function createResult($result, string $sql)
     {
         switch (\pg_result_status($result, \PGSQL_STATUS_LONG)) {
             case \PGSQL_EMPTY_QUERY:
@@ -265,7 +266,7 @@ final class PgSqlHandle implements Handle
                 foreach (self::DIAGNOSTIC_CODES as $fieldCode => $desciption) {
                     $diagnostics[$desciption] = \pg_result_error_field($result, $fieldCode);
                 }
-                throw new QueryExecutionError(\pg_result_error($result), $diagnostics);
+                throw new QueryExecutionError(\pg_result_error($result), $diagnostics, null, $sql);
 
             case \PGSQL_BAD_RESPONSE:
                 throw new FailureException(\pg_result_error($result));
@@ -286,7 +287,8 @@ final class PgSqlHandle implements Handle
     public function statementExecute(string $name, array $params): Promise
     {
         return call(function () use ($name, $params) {
-            return $this->createResult(yield from $this->send("pg_send_execute", $name, $params));
+            \assert(isset($this->statements[$name]), "Named statement not found when executing");
+            return $this->createResult(yield from $this->send("pg_send_execute", $name, $params), $this->statements[$name]->sql);
         });
     }
 
@@ -326,7 +328,7 @@ final class PgSqlHandle implements Handle
         }
 
         return call(function () use ($sql) {
-            return $this->createResult(yield from $this->send("pg_send_query", $sql));
+            return $this->createResult(yield from $this->send("pg_send_query", $sql), $sql);
         });
     }
 
@@ -343,7 +345,7 @@ final class PgSqlHandle implements Handle
         $params = Internal\replaceNamedParams($params, $names);
 
         return call(function () use ($sql, $params) {
-            return $this->createResult(yield from $this->send("pg_send_query_params", $sql, $params));
+            return $this->createResult(yield from $this->send("pg_send_query_params", $sql, $params), $sql);
         });
     }
 
@@ -378,12 +380,15 @@ final class PgSqlHandle implements Handle
                 use Struct;
                 public $refCount = 1;
                 public $promise;
+                public $sql;
             };
 
+            $storage->sql = $sql;
+
             $this->statements[$name] = $storage;
 
             try {
-                yield ($storage->promise = call(function () use ($name, $modifiedSql) {
+                yield ($storage->promise = call(function () use ($name, $modifiedSql, $sql) {
                     $result = yield from $this->send("pg_send_prepare", $name, $modifiedSql);
 
                     switch (\pg_result_status($result, \PGSQL_STATUS_LONG)) {
@@ -396,7 +401,7 @@ final class PgSqlHandle implements Handle
                             foreach (self::DIAGNOSTIC_CODES as $fieldCode => $description) {
                                 $diagnostics[$description] = \pg_result_error_field($result, $fieldCode);
                             }
-                            throw new QueryExecutionError(\pg_result_error($result), $diagnostics);
+                            throw new QueryExecutionError(\pg_result_error($result), $diagnostics, null, $sql);
 
                         case \PGSQL_BAD_RESPONSE:
                             throw new FailureException(\pg_result_error($result));
diff --git a/src/PqHandle.php b/src/PqHandle.php
index 9f774d6..9de6f98 100644
--- a/src/PqHandle.php
+++ b/src/PqHandle.php
@@ -163,6 +163,7 @@ final class PqHandle implements Handle
     }
 
     /**
+     * @param string|null Query SQL or null if not related.
      * @param callable $method Method to execute.
      * @param mixed ...$args Arguments to pass to function.
      *
@@ -172,7 +173,7 @@ final class PqHandle implements Handle
      *
      * @throws FailureException
      */
-    private function send(callable $method, ...$args): \Generator
+    private function send(?string $sql, callable $method, ...$args): \Generator
     {
         while ($this->busy) {
             try {
@@ -232,7 +233,7 @@ final class PqHandle implements Handle
 
             case pq\Result::NONFATAL_ERROR:
             case pq\Result::FATAL_ERROR:
-                throw new QueryExecutionError($result->errorMessage, $result->diag);
+                throw new QueryExecutionError($result->errorMessage, $result->diag, null, $sql ?? '');
 
             case pq\Result::BAD_RESPONSE:
                 throw new FailureException($result->errorMessage);
@@ -306,7 +307,7 @@ final class PqHandle implements Handle
 
         \assert($storage->statement instanceof pq\Statement, "Statement storage in invalid state");
 
-        return new Coroutine($this->send([$storage->statement, "execAsync"], $params));
+        return new Coroutine($this->send($storage->sql, [$storage->statement, "execAsync"], $params));
     }
 
     /**
@@ -334,7 +335,7 @@ final class PqHandle implements Handle
 
         \assert($storage->statement instanceof pq\Statement, "Statement storage in invalid state");
 
-        return new Coroutine($this->send([$storage->statement, "deallocateAsync"]));
+        return new Coroutine($this->send(null, [$storage->statement, "deallocateAsync"]));
     }
 
     /**
@@ -346,7 +347,7 @@ final class PqHandle implements Handle
             throw new \Error("The connection to the database has been closed");
         }
 
-        return new Coroutine($this->send([$this->handle, "execAsync"], $sql));
+        return new Coroutine($this->send($sql, [$this->handle, "execAsync"], $sql));
     }
 
     /**
@@ -361,7 +362,7 @@ final class PqHandle implements Handle
         $sql = Internal\parseNamedParams($sql, $names);
         $params = Internal\replaceNamedParams($params, $names);
 
-        return new Coroutine($this->send([$this->handle, "execParamsAsync"], $sql, $params));
+        return new Coroutine($this->send($sql, [$this->handle, "execParamsAsync"], $sql, $params));
     }
 
     /**
@@ -396,13 +397,16 @@ final class PqHandle implements Handle
                 public $refCount = 1;
                 public $promise;
                 public $statement;
+                public $sql;
             };
 
+            $storage->sql = $sql;
+
             $this->statements[$name] = $storage;
 
             try {
                 $storage->statement = yield (
-                    $storage->promise = new Coroutine($this->send([$this->handle, "prepareAsync"], $name, $modifiedSql))
+                    $storage->promise = new Coroutine($this->send($sql, [$this->handle, "prepareAsync"], $name, $modifiedSql))
                 );
             } catch (\Throwable $exception) {
                 unset($this->statements[$name]);
@@ -420,7 +424,7 @@ final class PqHandle implements Handle
      */
     public function notify(string $channel, string $payload = ""): Promise
     {
-        return new Coroutine($this->send([$this->handle, "notifyAsync"], $channel, $payload));
+        return new Coroutine($this->send(null, [$this->handle, "notifyAsync"], $channel, $payload));
     }
 
     /**
@@ -437,6 +441,7 @@ final class PqHandle implements Handle
 
             try {
                 yield from $this->send(
+                    null,
                     [$this->handle, "listenAsync"],
                     $channel,
                     static function (string $channel, string $message, int $pid) use ($emitter) {
@@ -474,7 +479,7 @@ final class PqHandle implements Handle
         if (!$this->handle) {
             $promise = new Success; // Connection already closed.
         } else {
-            $promise = new Coroutine($this->send([$this->handle, "unlistenAsync"], $channel));
+            $promise = new Coroutine($this->send(null, [$this->handle, "unlistenAsync"], $channel));
         }
 
         $promise->onResolve([$emitter, "complete"]);
diff --git a/src/QueryExecutionError.php b/src/QueryExecutionError.php
index ab7e8ad..9627844 100644
--- a/src/QueryExecutionError.php
+++ b/src/QueryExecutionError.php
@@ -9,9 +9,9 @@ class QueryExecutionError extends QueryError
     /** @var mixed[] */
     private $diagnostics;
 
-    public function __construct(string $message, array $diagnostics, \Throwable $previous = null)
+    public function __construct(string $message, array $diagnostics, \Throwable $previous = null, string $query = '')
     {
-        parent::__construct($message, 0, $previous);
+        parent::__construct($message, $query, $previous);
         $this->diagnostics = $diagnostics;
     }