- A distinction between delay and immediately retrieve
- Second, the class-level search and retrieval association level
A distinction between delay and immediately retrieve
- Retrieving immediately:
- When you execute a line of code, and immediately issue SQL statements to query.
- get()
- Delay Search:
- When we execute a line of code will not immediately issue SQL query statements. SQL statement will be sent when the real use of the object.
- load();
Second, the class-level search and retrieval association level
- Class level of Search:
- Lazy arranged on <class> tag
The associated level of Search:
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/ Above lazy.
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When an object query, the query whether the associated object?
When associated with the query object is retrieved using the delay?
From one of a plurality of associated one of:
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fetch: control the type of sql statement
- join: send SQL queries associated object pressing the left outer join .fetch = "join" so lazy ignored.
- select: defaults, sending multiple SQL query associated objects.
- subselect: Send subquery associated objects (need to use the Query interface test).
lazy: retrieving the object associated control whether to use delay.
- true: The default value associated with the query to retrieve objects when using delay
- false: When a query object is not associated with the use of delayed retrieval.
- extra: its laziness.
If fetch is the case of join, lazy property is ignored.
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In the multi-party associated with a party:
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- fetch: control SQL statements sent format
- join: send an urgent left outer join query associated object .fetch = "join", lay property is ignored.
- select: send multiple SQL to retrieve associated objects.
- lazy: when the associated object retrieved, whether to use delay
- false: do not delay
- proxy:. Use agent retrieves the order amount when the customer whether to immediately retrieve the mapping file by the Customer object
The lazy attribute to decide. - no-proxy: do not use a proxy
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