fun listVendors() = ds.withConnection {
        prepareStatement("""
            SELECT id, name
            FROM vendor
            ORDER BY name""").toModel { Vendor(it) }
    }

    fun insertVendor(vendor: Vendor) = ds.withConnection {
        prepareStatement("INSERT INTO vendor (name) VALUES (?)").exec {
            setString(1, vendor.name)
        }
    }

    fun updateVendor(vendor: Vendor) = ds.withConnection {
        prepareStatement("UPDATE vendor SET name = ? WHERE id = ?").exec {
            setString(1, vendor.name)
            setInt(2, vendor.id)
        }
    }

    fun deleteVendor(vendor: Vendor) = ds.withConnection { 
        prepareStatement("DELETE FROM vendor WHERE id = ?").exec { 
            setInt(1, vendor.id)
        }
    }