1)动态 SQL 动态SQL 语句概述 https://mybatis.org/mybatis-3/dynamic-sql.html 动态SQL 之<if> 根据实体类的不用取值,使用不同的 SQL 进行查询 <!-- 多条件组合查询用户:if案例 -->select * from user where 1=1<iftest="id!=null">and id=#{id}</if><iftest="username!=null">and userna...
ORM(Object-Relational Mapping)是一种将数据库表与程序对象之间进行映射的技术。通过ORM框架,开发者可以使用面向对象的方式操作数据库,而无需直接编写复杂的SQL语句。其核心优势包括: 降低开发复杂度:通过对象操作替代SQL语句,减少重复代码。 提高可维护性:代码结构更清晰,便于后期维护和扩展。 跨数据库兼容性:ORM框架...
要启用此支持,您的表对象应扩展 org.mybatis.dynamic.sql.AliasableSqlTable 而不是 org.mybatis.dynamic.sql.SqlTable,如下所示: public static final class User extends AliasableSqlTable<User> { public final SqlColumn<Integer> userId = column("user_id", JDBCType.INTEGER); public final SqlColumn<S...
在《Java 使用线程池分批插入或者更新数据》中介绍了如何在Java端批量切分数据,然后,使用线程池将被切分的数据传入相应DAO层的方法后,即可完整实现批量操作。小编在《5 MyBatis动态sql中foreach标签的使用》中详细描述了foreach标签,这里简要概述批量删除、更新和查找。 首先,mysql需要数据库连接配置&allowMultiQueries=t...
项目之前是springboot简单的mybatis接入mysql,后续需求要接入clickhouse,顺便借此机会引入mybatis-plus,因为在迭代过程中时不时要加字段,每次加字段都要手动改mapper.xml文件的resultmap等sql实在是很没必要。 但在接入之后,在往clickhouse插入测试数据时,使用了mybatis-plus自带的batchSave()方法,发现速度非常慢,完全不是...
Basic SQL queries Passing parameters Composing with LINQ Change Tracking Show 3 more Entity Framework Core allows you to drop down to SQL queries when working with a relational database. SQL queries are useful if the query you want can't be expressed using LINQ, or if a LINQ query ...
GitHub milestone:https://github.com/mybatis/mybatis-dynamic-sql/issues?q=milestone%3A1.1.4+ Added support for reusing WHERE clauses among count, delete, select, and update statements (#152) Improved Kotlin support. Previously, several overloaded methods could collide causing queries to be fragile...
Slave_SQL_Running:Yes 返回如下: ***1.row*** Slave_IO_State:Waitingformasterto Master_Host:10.1.176.158 MasterUser:backup Master_Port: Connect_Retry: Master_Log_Filemysql-bin.000010 Read_Master_Log_Pos:106 Relay_LogFile:bogon-relay-bin.000002 Relay_Log_Pos:251 Relay_Master__File...
The maximum amount of results per page is 50, it is recommended to paginate those queries that are expected to return more than 50 results. The maximum amount of requests per minute allowed for each IP is 180; please contact support if this causes a limitation for you. Common errors and ...
noborus/trdsql - CLI tool that can execute SQL queries on CSV, LTSV, JSON, YAML and TBLN. Can output to various formats. [MIT License] (⭐️2091) nore-dev/fman - TUI File Manager [MIT License] (⭐️330) oapi-codegen/oapi-codegen - Generate Go client and server boilerplate ...