- 在mybatis-config.xml中配置分页插件,插件配置必须放在mapper前面
<plugins> <plugin interceptor="com.rrtong.frame.dao.PaginationInterceptor"> <property name="dialect" value="oracle"></property> </plugin> </plugins>
- Mybatis分页拦截器获取sql
/*以下得到的是要执行的sql语句,并不是配置的sql语句*/ StatementHandler statementHandler = (StatementHandler)invocation.getTarget(); BoundSql boundSql = statementHandler.getBoundSql(); String originalSql = boundSql.getSql();
- 出现java.lang.AbstractMethodError: org.mybatis.spring.transaction.SpringManagedTransactionFactory.newTransaction(Ljava/sql/Connection;)Lorg/apache/ibatis/transaction/Transaction;
https://mybatis.googlecode.com/files/mybatis-spring-1.2.1.zip
- Mybaitis参数严格区分大小写
mybatis 配置文件中的参数绑定区分大小写,必须与传递的参数名保持一致
- 出现数据类型111时,这是因为数据库字段数据类型与entity中的字段定义的数据类型不一致导致的,有以下两种方法解决
1、设定entity的数据类型与数据库类型一致
2、在sql中定义参数的数据类型,比如
where userCode = #{userCode, jdbcType=VARCHAR}
- 实现数据库字段与实体字段的关系对应
<resultmap id="Archive" type="Archive"> <id column="ARCHIVESKEY" property="archiveKey"></id> <result column="title" property="archiveTitle"></result> </resultmap>
- 定义oracle数据库的mybatis获取主键并返回的配置,mybatis before after设置
<p> <selectkey keyproperty="archiveKey" order="BEFORE" resulttype="String"> SELECT SEQ_ARCHIVE.NEXTVAL FROM DUAL </selectkey></p>
- 定义其他数据库的Mybatis获取主键并返回的配置
<insert id="insertUser" usegeneratedkeys="true" keyproperty="userId" parametertype="com.mybatis.User"> insert into user(userName,password) values(#{userName},#{password}) </insert>
- 定义mybatis查询结果注入到实体中
<resultmap id="Archive" type="Archive"> <id property="archiveKey"></id> <result column="title" property="archiveTitle"></result> </resultmap> <select id="getArchive" parametertype="HashMap" resultmap="Archive"> select SPAARCHIVESKEY, TITLE from Archives where USERCODE = #{userCode, jdbcType=VARCHAR} And VALID= #{valid, jdbcType=VARCHAR} </select>
- 定义Mybaitis更新数据库表记录
<update id="updateArchive" parametertype="Archive"> update Tbl_ARCHIVES set title = #{archiveTitle}, content = #{content}, feeValue = #{feeValue} security = #{security}, subjectType = #{subjectType}, gradeType = #{gradeType}, gather = #{gather}, archiveType = #{archiveType}, keyWordName = #{keyWordName} where archivesKey = #{archiveKey} </update>
- 定义mybatis删除数据表记录的方式
<delete id="deleteArchive" parametertype="String"> delete from title where spaArchivesKey = #{archiveKey}</delete>

MySQLoffersvariousstorageengines,eachsuitedfordifferentusecases:1)InnoDBisidealforapplicationsneedingACIDcomplianceandhighconcurrency,supportingtransactionsandforeignkeys.2)MyISAMisbestforread-heavyworkloads,lackingtransactionsupport.3)Memoryengineis

Common security vulnerabilities in MySQL include SQL injection, weak passwords, improper permission configuration, and unupdated software. 1. SQL injection can be prevented by using preprocessing statements. 2. Weak passwords can be avoided by forcibly using strong password strategies. 3. Improper permission configuration can be resolved through regular review and adjustment of user permissions. 4. Unupdated software can be patched by regularly checking and updating the MySQL version.

Identifying slow queries in MySQL can be achieved by enabling slow query logs and setting thresholds. 1. Enable slow query logs and set thresholds. 2. View and analyze slow query log files, and use tools such as mysqldumpslow or pt-query-digest for in-depth analysis. 3. Optimizing slow queries can be achieved through index optimization, query rewriting and avoiding the use of SELECT*.

To monitor the health and performance of MySQL servers, you should pay attention to system health, performance metrics and query execution. 1) Monitor system health: Use top, htop or SHOWGLOBALSTATUS commands to view CPU, memory, disk I/O and network activities. 2) Track performance indicators: monitor key indicators such as query number per second, average query time and cache hit rate. 3) Ensure query execution optimization: Enable slow query logs, record and optimize queries whose execution time exceeds the set threshold.

The main difference between MySQL and MariaDB is performance, functionality and license: 1. MySQL is developed by Oracle, and MariaDB is its fork. 2. MariaDB may perform better in high load environments. 3.MariaDB provides more storage engines and functions. 4.MySQL adopts a dual license, and MariaDB is completely open source. The existing infrastructure, performance requirements, functional requirements and license costs should be taken into account when choosing.

MySQL uses a GPL license. 1) The GPL license allows the free use, modification and distribution of MySQL, but the modified distribution must comply with GPL. 2) Commercial licenses can avoid public modifications and are suitable for commercial applications that require confidentiality.

The situations when choosing InnoDB instead of MyISAM include: 1) transaction support, 2) high concurrency environment, 3) high data consistency; conversely, the situation when choosing MyISAM includes: 1) mainly read operations, 2) no transaction support is required. InnoDB is suitable for applications that require high data consistency and transaction processing, such as e-commerce platforms, while MyISAM is suitable for read-intensive and transaction-free applications such as blog systems.

In MySQL, the function of foreign keys is to establish the relationship between tables and ensure the consistency and integrity of the data. Foreign keys maintain the effectiveness of data through reference integrity checks and cascading operations. Pay attention to performance optimization and avoid common errors when using them.


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