MyBatis中批量插入資料，多重forEach迴圈

在業務開發過程中，遇到批量插入時，需要進行多重forEach迴圈的情況。下面是一個實際應用：

public class SysRoleData extends DataEntity<SysRoleData> {
   
   private static final long serialVersionUID = 1L;
   private String kind;      //類別（1：按部門2：按角色）
   private String roleId;    // role_id
   private String roleName;  //角色名稱
   private String officeId;   //office_id
   private String officeName;  //部門名稱
   private String type;      // 1.品牌 2.品類 3.品牌&品類
   private String dataId;    // 資料ID品牌
   private String dataName;    //資料名稱品牌
   private String dataIds;       // 資料ID品類
   private String dataNames;    //資料名稱品類
   private String groupNo;  //分組標識
   private String useable; //是否可用(1:可用,0:不可用）
   private String remarks; //備註
   private List<String> officeIdList = Lists.newArrayList();
   private List<String> roleIdList = Lists.newArrayList();
   private List<BrandCategoryVO> dataList = Lists.newArrayList();
   public SysRoleData() {
      super();
   }

   public SysRoleData(String id){
      super(id);
   }

   public String getKind() {
      return kind;
   }

   public void setKind(String kind) {
      this.kind = kind;
   }

   @Length(min=0, max=45, message="role_id長度必須介於 0 和 45 之間")
   public String getRoleId() {
      return roleId;
   }

   public void setRoleId(String roleId) {
      this.roleId = roleId;
   }

   public String getRoleName() {
      return roleName;
   }

   public void setRoleName(String roleName) {
      this.roleName = roleName;
   }

   public String getOfficeName() {
      return officeName;
   }

   public void setOfficeName(String officeName) {
      this.officeName = officeName;
   }

   @Length(min=0, max=45, message="office_id長度必須介於 0 和 45 之間")
   public String getOfficeId() {
      return officeId;
   }

   public void setOfficeId(String officeId) {
      this.officeId = officeId;
   }

   @Length(min=0, max=4, message="品類長度必須介於 0 和 45 之間")
   public String getType() {
      return type;
   }

   public void setType(String type) {
      this.type = type;
   }

   @NotNull
   public String getDataId() {
      return dataId;
   }

   public void setDataId(String dataId) {
      this.dataId = dataId;
   }

   public String getDataName() {
      return dataName;
   }

   public void setDataName(String dataName) {
      this.dataName = dataName;
   }

   public String getDataIds() {
      return dataIds;
   }

   public void setDataIds(String dataIds) {
      this.dataIds = dataIds;
   }

   public String getDataNames() {
      return dataNames;
   }

   public void setDataNames(String dataNames) {
      this.dataNames = dataNames;
   }

   public String getUseable() {
      return useable;
   }

   public void setUseable(String useable) {
      this.useable = useable;
   }

   public String getRemarks() {
      return remarks;
   }

   public void setRemarks(String remarks) {
      this.remarks = remarks;
   }

   public List<BrandCategoryVO> getDataList() {
      return dataList;
   }

   public void setDataList(List<BrandCategoryVO> dataList) {
      this.dataList = dataList;
   }

   public List<String> getOfficeIdList() {
      return officeIdList;
   }

   public void setOfficeIdList(List<String> officeIdList) {
      this.officeIdList = officeIdList;
   }

   public List<String> getRoleIdList() {
      return roleIdList;
   }

   public void setRoleIdList(List<String> roleIdList) {
      this.roleIdList = roleIdList;
   }

   public String getGroupNo() {
      return groupNo;
   }

   public void setGroupNo(String groupNo) {
      this.groupNo = groupNo;
   }
}

如上所示為一個實體類，會有dataList和roleIdList或officeIdList，在批量插入時從而形成多重迴圈。

上圖為列表頁面，

上圖為新增頁面。部門名稱和品牌，品類名稱支援多選，而在儲存時，需要將其拆分儲存。在查詢時通過group_concat函式進行聚合展示在列表頁面。

故在批量插入資料時：

<insert id="insert">
   INSERT INTO sys_role_data(
   kind,
   role_id,
   office_id,
   type,
   data_id,
   data_name,
   group_no,
   useable,
   remarks,
   create_date,
   create_by,
   update_date,
   update_by
   )VALUES
   <if test="kind != null and kind == 0">
      <foreach collection="officeIdList" item="officeId" separator=",">
         <foreach collection="dataList" item="data" separator=",">
         (
            #{kind},
            null,
            #{officeId},
            #{type},
            #{data.id},
            #{data.name},
            #{groupNo},
            #{useable},
            #{remarks},
            #{createDate},
            #{createBy.id},
            #{updateDate},
            #{updateBy.id}
         )
         </foreach>
      </foreach>
   </if>
   <if test="kind != null and kind == 1">
      <foreach collection="roleIdList" item="roleId" separator=",">
         <foreach collection="dataList" item="data" separator=",">
         (
            #{kind},
            #{roleId},
            null,
            #{type},
            #{data.id},
            #{data.name},
            #{groupNo},
            #{useable},
            #{remarks},
            #{createDate},
            #{createBy.id},
            #{updateDate},
            #{updateBy.id}
         )
         </foreach>
      </foreach>
   </if>
</insert>

由上面sql可以看出，根據kind不同，進行相應的雙重forEach迴圈插入資料。