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Demand analysis 1.3 The attachment seems unable to generate a template, because the uid of each target should be added to the attachment to identify the recruiter. The idea of the first two versions is to generate an attachment template, and then import the attachment when creating the template, so that the attachment can be directly sent ...

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resultMap mapping What is resultMap? Simply put, it is a Map like structure that maps the fields in the database to the attribute fields in the JavaBean, so that one-to-one mapping can be achieved.How to write the above example using resultMap? As follows: <!--Create a resultMap mapping--> <resultMap id="patResultMap" type="com.xxx. ...

Cache penetration problem? Cache penetration: it is specified to use some nonexistent key s for a large number of queries on Redis, resulting in failure to hit. Each request will be sent to the persistence layer for query, resulting in great pressure on the database. What are the solutions? Implement flow restriction on our service interface ...

 1,AbstractRoutingDataSource     Spring boot provides AbstractRoutingDataSource to select the current data source according to user-defined rules, so that we can set the data source before executing the query. The data source that can be dynamically routed is implemented before each database query operation. Its abstract method determineCurre ...

HashMap initializes the collection using HashMap(int initialCapacity). By default, the capacity of HashMap is 16. However, if the user specifies a number as the capacity through the constructor, Hash will select a power greater than the first 2 of the number as the capacity. For example, if 3 is specified, the capacity is 4; If 7 is specified, ...

What the project wants to do Logon function (with authentication code)Registration function (to be able to check if a database has the same name)Each user needs his or her own address list (the ability to add addresses)Show function of goods (there should be page-by-page display in the overall display and detailed display after clicking on the ...

join query Meaning: it is also called multi table query. When the query fields come from multiple tables, the join query will be used Cartesian product phenomenon: Table 1 has m Row, table 2 has n Line, result=m*n that 's ok Cause: there is no valid connection condition How to avoid: adding valid connection conditions As follows: #Without ...

Several MySQL database services of different versions are installed in super simple Win10 (currently 5.7 and 8.0.26) 1, MySQL 8 0 installation package download? 1. Official website Download address: https://downloads.mysql.com/archives/community/ Download the following versions: 2. Baidu cloud: Link: https://pan.baidu.com/s/198TCAMF ...

Welcome to the MySQL technical articles shared by the great SQL community. If you have any questions or want to learn, you can leave a message in the comment area below. After seeing it, you will answer itThis article introduces you to a method of sql syntax parsing and tracing using mysql parser and bison's debugging options.In the process of ...