create_purchasers: Remove `DEFAULT UTC_TIMESTAMP()`

Ended up with this error when running my migrations against the
production server:

    error: migration failed in line 0: BEGIN;

    CREATE TABLE purchasers (
        id INT AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        email VARCHAR(255) NOT NULL,
        secret VARCHAR(255),
        created_at DATETIME NOT NULL DEFAULT UTC_TIMESTAMP(),
        updated_at DATETIME NOT NULL DEFAULT UTC_TIMESTAMP()
    );

    CREATE TRIGGER purchasers_updated_at
        BEFORE UPDATE
        ON purchasers FOR EACH ROW
            SET NEW.updated_at = UTC_TIMESTAMP();

    COMMIT;
     (details: Error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UTC_TIMESTAMP(),
        updated_at DATETIME NOT NULL DEFAULT UTC_TIMESTAMP()
    );

    CR' at line 6)

Using MySQL 5.6.34 in production and MariaDB 10.3.10 locally. Guess you
can't use `DEFAULT UTC_TIMESTAMP()` there.

To use `UTC_TIMESTAMP()`, create a couple new triggers to set the
timestamp in the `created_at` and `updated_at` columns.

2 files changed, 16 insertions, 4 deletions

diff --git a/license-generator/migrations/20181109031633_create_purchasers.down.sql b/license-generator/migrations/20181109031633_create_purchasers.down.sql
index d17db9c..3fa17a5 100644
--- a/license-generator/migrations/20181109031633_create_purchasers.down.sql
+++ b/license-generator/migrations/20181109031633_create_purchasers.down.sql
@@ -1,6 +1,8 @@
 BEGIN;
 
-DROP TRIGGER purchasers_updated_at;
+DROP TRIGGER purchasers_created_at_before_insert;
+DROP TRIGGER purchasers_updated_at_before_insert;
+DROP TRIGGER purchasers_updated_at_before_update;
 DROP TABLE purchasers;
 
 COMMIT;
diff --git a/license-generator/migrations/20181109031633_create_purchasers.up.sql b/license-generator/migrations/20181109031633_create_purchasers.up.sql
index 8bf597c..19669bd 100644
--- a/license-generator/migrations/20181109031633_create_purchasers.up.sql
+++ b/license-generator/migrations/20181109031633_create_purchasers.up.sql
@@ -5,11 +5,21 @@ CREATE TABLE purchasers (
     name VARCHAR(255) NOT NULL,
     email VARCHAR(255) NOT NULL,
     secret VARCHAR(255),
-    created_at DATETIME NOT NULL DEFAULT UTC_TIMESTAMP(),
-    updated_at DATETIME NOT NULL DEFAULT UTC_TIMESTAMP()
+    created_at DATETIME NOT NULL,
+    updated_at DATETIME NOT NULL
 );
 
-CREATE TRIGGER purchasers_updated_at
+CREATE TRIGGER purchasers_created_at_before_insert
+    BEFORE INSERT
+    ON purchasers FOR EACH ROW
+        SET NEW.created_at = UTC_TIMESTAMP();
+
+CREATE TRIGGER purchasers_updated_at_before_insert
+    BEFORE INSERT
+    ON purchasers FOR EACH ROW
+        SET NEW.updated_at = UTC_TIMESTAMP();
+
+CREATE TRIGGER purchasers_updated_at_before_update
     BEFORE UPDATE
     ON purchasers FOR EACH ROW
         SET NEW.updated_at = UTC_TIMESTAMP();