Migration Guide

-- Migration: 001_add_disputes_table.sql

CREATE TABLE IF NOT EXISTS op_disputes (
  id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  -- ...
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- Add column only if it does not exist
SET @dbname = DATABASE();
SET @tablename = 'op_transactions';
SET @columnname = 'dispute_status';
SET @preparedStatement = (SELECT IF(
  (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
   WHERE TABLE_SCHEMA = @dbname AND TABLE_NAME = @tablename AND COLUMN_NAME = @columnname) > 0,
  'SELECT 1',
  CONCAT('ALTER TABLE ', @tablename, ' ADD COLUMN ', @columnname, ' VARCHAR(50) DEFAULT NULL')
));
PREPARE alterIfNotExists FROM @preparedStatement;
EXECUTE alterIfNotExists;
DEALLOCATE PREPARE alterIfNotExists;