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

"Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'surplusAmount' cannot be 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。但是我需要拖车参数inventoryId和materialTypeId才能决定inventoryId。所以有人可以给我一些答案吗？

Answer 1

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

出现问题是因为对于您在列表中传递的某些 inventoryId，数据库比您在作为参数传递的列表中提供的 materialTypeId 多。

因此生成的 case 语句为缺少的 materialTypeId 生成 NULL 并且尝试将 surplusAmount 设置为 NULL 导致错误。

MySQLIntegrityConstraintViolationException：列“”不能为空

MySQLIntegrityConstraintViolationException: Column '' cannot be null

mysql

case

case-when

mybatis