MySQLIntegrityConstraintViolationException：列''不能为空

Question

mapper:
<update id="updateSurplusAmountByPrimaryKeyAndMaterialTypeId" 
  parameterType="java.util.List">
    update db_logistics.table_inventory_material
    set surplusAmount=
    <foreach collection="list" item="item" index="index"
             separator=" " open="case" close="end">
        when inventoryId=#{item.inventoryId} and materialTypeId=# 
    {item.materialTypeId} then #{item.surplusAmount,jdbcType=INTEGER}
    </foreach>
    where inventoryId in
    <foreach collection="list" index="index" item="item"
             separator="," open="(" close=")">
        #{item.inventoryId,jdbcType=BIGINT}
    </foreach>
</update>
 fun updateSurplusAmountByPrimaryKeyAndMaterialTypeId(records: 
List<InventoryMaterial>): Int
data class InventoryMaterial(
    var inventoryId: Int = 0,
    var materialTypeId: Int = 0,
    var surplusAmount: Int = 0,
    var consumeSpeed: Float = 0f,
    var consumeAlarmDayCount: Int = 0,
    var updateDataTime: LocalDateTime =  LocalDateTime.now())

错误

“引起：com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException：列'surplusAmount'不能为null”

当我将when inventoryId=#{item.inventoryId} and materialTypeId=#{item.materialTypeId} 修改为when inventoryId=#{item.inventoryId} 时，错误消失了。但我需要拖车参数inventoryId和materialTypeId可以决定inventoryId。有人可以给我一些答案吗？

Answer 1

执行的查询通过table_inventory_material从inventoryId中选择记录，并使用每个materialTypeId的指定数据更新它们。

问题发生的原因是，对于您在列表中传递的某些inventoryId，数据库具有比您作为参数传递的列表中提供的更多materialTypeIds。

所以生成的case语句为缺少的NULL产生materialTypeId，并且尝试将surplusAmount设置为NULL导致错误。