Get formatted query from Pool.query() method

lib/Connection.js

@@ -179,8 +179,10 @@ Connection.prototype.query = function(sql, values, cb) {
   if (!(typeof sql == 'object' && 'typeCast' in sql)) {
     query.typeCast = this.config.typeCast;
   }
-
-  query.sql = this.format(query.sql, query.values);
+  if (!query.isFormatted) {
+    query.sql = this.format(query.sql, query.values);
+    query.isFormatted = true;
+  }
 
   return this._protocol._enqueue(query);
 };

lib/Pool.js

@@ -195,6 +195,10 @@ Pool.prototype.query = function (sql, values, cb) {
     conn.query(query);
   });
 
+  if (!query.isFormatted) {
+    query.isFormatted = true;
+    query.sql = this.format(query.sql, query.values);
+  }
   return query;
 };
 
@@ -255,6 +259,13 @@ Pool.prototype.escapeId = function escapeId(value) {
   return mysql.escapeId(value, false);
 };
 
+Pool.prototype.format = function(sql, values) {
+  if (typeof this.config.connectionConfig.queryFormat == "function") {
+    return this.config.connectionConfig.queryFormat.call(this, sql, values, this.config.connectionConfig.timezone);
+  }
+  return mysql.format(sql, values, this.config.connectionConfig.stringifyObjects, this.config.connectionConfig.timezone);
+};
+
 function spliceConnection(array, connection) {
   var index;
   if ((index = array.indexOf(connection)) !== -1) {

lib/protocol/sequences/Query.js

@@ -11,6 +11,7 @@ Util.inherits(Query, Sequence);
 function Query(options, callback) {
   Sequence.call(this, options, callback);
 
+  this.isFormatted = false;
   this.sql = options.sql;
   this.values = options.values;
   this.typeCast = (options.typeCast === undefined)

test/unit/pool/test-query-return-formatted.js

@@ -0,0 +1,60 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var pool1   = common.createPool({port: common.fakeServerPort});
+var pool2   = common.createPool({port: common.fakeServerPort, queryFormat: queryFormat});
+
+
+function queryFormat(query, values, tz) {
+  if (!values) {
+    return query;
+  }
+
+  var escape = this.escape.bind(this);
+
+  return query.replace(/\:(\w+)/g, function (txt, key) {
+    if (values.hasOwnProperty(key)) {
+      return escape(values[key]);
+    }
+    return txt;
+  });
+}
+
+var server = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function (err) {
+  assert.ifError(err);
+
+
+
+  // When the fix is applied, this query demonstrates that connection.query(),
+  // which gets invoked internally by pool.query(), will not re-format the query
+  // a second time. Re-formatting the query a second time in this case would cause
+  // an error when the question marks inside the string 'John ? J ?' are interpreted
+  // as placeholders for values.
+
+  assert.equal(pool1.query('SELECT ?? FROM ?? WHERE id=? OR name=?', [['name', 'rdate'], 'dummytable', 1, "John ? J ?"]).sql, 'SELECT `name`, `rdate` FROM `dummytable` WHERE id=1 OR name=\'John ? J ?\'');
+
+
+
+  // This one will will fail before the fix is applied
+
+  assert.equal(pool2.query('SELECT :a1, :a2', { a1: 1, a2: 'two' }).sql, 'SELECT 1, \'two\'');
+
+
+
+  // These last 2 will work before and after the fix is applied as there is no transformation performed
+
+  assert.equal(pool2.query('SELECT :a1', []).sql, 'SELECT :a1');
+  assert.equal(pool2.query('SELECT :a1').sql, 'SELECT :a1');
+
+
+
+  pool1.end(function (err) {
+    assert.ifError(err);
+    pool2.end(function (err) {
+      assert.ifError(err);
+      server.destroy();
+    });
+  });
+
+});