INSERT_UPDATE adds new input data to the table, or updates existing rows with input data that has matching primary key values.
INSERT_UPDATE将新的输入数据添加到表中，或者用具有匹配主键值的输入数据更新现有的行。
When ON delete set NULL is active, when a record is deleted from the parent table, all records in the child table with matching foreign key values are set to NULL.
当ON DELETESETNULL规则被激活时，如果一条记录从父表中删除，子表中的所有记录以及匹配的外键值都被设置为NULL。
ON DELETE CASCADE—When a record is deleted from the parent table, all records in the child table with matching foreign key values are also deleted.
ON DELETECASCADE —当一条记录从父表中删除时，子表中的所有记录以及匹配的外键值都全部被删除。
When an ON delete CASCADE rule is active, all records in the child table with matching foreign key values are deleted when a record is deleted from the parent table.
当ONDELETECASCADE规则被激活时，当一条记录从父表中删除时，子表中的所有记录以及匹配的外键值都被删除。
The key technique of the technical scheme for electronic sand table, such as data processing, terrain modeling, feature matching, is introduced in details in this paper.
然后提出并实现面向土地利用规划的电子沙盘制作的技术方案，详细介绍了数据处理、地形模拟与要素匹配等关键技术。
The key technique of the technical scheme for electronic sand table, such as data processing, terrain modeling, feature matching, is introduced in details in this paper.
然后提出并实现面向土地利用规划的电子沙盘制作的技术方案，详细介绍了数据处理、地形模拟与要素匹配等关键技术。
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