From 8d1a7832d2ff19c5364ce64addc3a9d48f3d4b78 Mon Sep 17 00:00:00 2001
From: wubzz <wubzz94@hotmail.com>
Date: Fri, 1 Apr 2016 23:28:15 +0200
Subject: [PATCH] .renameColumn should not drop defaultValue or nullable state.
 Currently this happens for mysql. Fixes #933

---
 src/dialects/mysql/schema/tablecompiler.js | 11 ++++++++-
 test/integration/schema/index.js           | 27 ++++++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/dialects/mysql/schema/tablecompiler.js b/src/dialects/mysql/schema/tablecompiler.js
index ee97a72afc..f1934e4b7d 100644
--- a/src/dialects/mysql/schema/tablecompiler.js
+++ b/src/dialects/mysql/schema/tablecompiler.js
@@ -77,8 +77,17 @@ assign(TableCompiler_MySQL.prototype, {
               if (!refs.length) { return; }
               return compiler.dropFKRefs(runner, refs);
             }).then(function () {
+              let sql = `alter table ${table} change ${wrapped} ${column.Type}`;
+
+              if(String(column.Null).toUpperCase() !== 'YES') {
+                sql += ` NOT NULL`
+              }
+              if(column.Default !== void 0 && column.Default !== null) {
+                sql += ` DEFAULT '${column.Default}'`
+              }
+
               return runner.query({
-                sql: 'alter table ' + table + ' change ' + wrapped + ' ' + column.Type
+                sql: sql
               });
             }).then(function () {
               if (!refs.length) { return; }
diff --git a/test/integration/schema/index.js b/test/integration/schema/index.js
index 1645fec947..27cd694eb5 100644
--- a/test/integration/schema/index.js
+++ b/test/integration/schema/index.js
@@ -438,6 +438,33 @@ module.exports = function(knex) {
           tbl.renameColumn('id', 'id_new');
         });
       });
+
+      it('#933 - .renameColumn should not drop null or default value', function() {
+        return knex.transaction((tr) => {
+          let getColInfo = () => tr('renameColTest').columnInfo();
+          return tr.schema.dropTableIfExists('renameColTest')
+            .createTable('renameColTest', (table) => {
+              table.integer('colnameint').defaultTo(1);
+              table.string('colnamestring').defaultTo('knex').notNullable();
+            })
+            .then(getColInfo)
+            .then((colInfo) => {
+              expect(colInfo.colnameint.defaultValue).to.equal('1');
+              expect(colInfo.colnamestring.defaultValue).to.contain('knex'); //Using contain because of different response per dialect. IE mysql 'knex', postgres 'knex::character varying'
+              expect(colInfo.colnamestring.nullable).to.equal(false);
+              return tr.schema.table('renameColTest', (table) => {
+                table.renameColumn('colnameint', 'colnameintchanged');
+                table.renameColumn('colnamestring', 'colnamestringchanged');
+              })
+            })
+            .then(getColInfo)
+            .then((columnInfo) => {
+              expect(columnInfo.colnameintchanged.defaultValue).to.equal('1');
+              expect(columnInfo.colnamestringchanged.defaultValue).to.contain('knex');
+              expect(columnInfo.colnamestringchanged.nullable).to.equal(false);
+            });
+        });
+      });
     });
 
   });