- 
        
          
mysql
        
        
          
            ~> 0.13.0
          
        
        
        
          MySQL connector for Crystal
        
        {'github' => 'crystal-lang/crystal-mysql', 'version' => '~> 0.13.0'}
- 
        
          
pg
        
        
          
            ~> 0.23.2
          
        
        
        
          A Postgres driver
        
        {'github' => 'will/crystal-pg', 'version' => '~> 0.23.2'}
- 
        
          
sqlite3
        
        
          
            ~> 0.18.0
          
        
        
        
          SQLite3 bindings
        
        {'github' => 'crystal-lang/crystal-sqlite3', 'version' => '~> 0.18.0'}