达梦数据库集成mybatis-plus

先总结

• 库名，表名和字段名尽量大写。小写必须要使用双引号，不然会报各种问题，包括【语法解析错误】，【无效的列名】
• 如果列名必须小写，那么要自己写mapper.xml。mybatis-plus在操作insert的时候会报【dm.jdbc.driver.DMException: 无效的列】，加了双引号也不行。参见我另外一篇文章mybatis-plus insert无效的列。

以下是部分代码

包引用

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dmdba.demo</groupId>
    <artifactId>dmdbaDemo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dmdbaDemo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.dameng</groupId>
            <artifactId>DmJdbcDriver18</artifactId>
            <version>8.1.3.62</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

表结构

CREATE TABLE "test"."user"
(
"ID" INTEGER IDENTITY(1, 1) NOT NULL,
"USERNAME" VARCHAR2(50),
"login_name" VARCHAR2(50),
UNIQUE("ID")) STORAGE(ON "MAIN", CLUSTERBTR) ;

mapper

错误案例：login_name没有带双引号，不带的话就变大写了，报错【无效的列名[LOGIN_NAME]】。当然，如果列名本身是大写的就不用带双引号了
另外，库名和表名也要带双引号，不然就大写，不然报【语法分析出错】

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--命名空间  会映射到 接口-->
<mapper namespace="com.dmdba.demo.dmdbademo.mappers.UserMapper">
    <insert id="ins">
        insert into "test"."user" ("login_name")
        values(#{loginName})
    </insert>
</mapper>

entity

注意，库名和表名需要带双引号，不想带的话要大写
如果小写而没有带双引号则报【语法分析出错】

@Data
@TableName("\"test\".\"user\"")
public class User {
    @TableId(type = IdType.AUTO, value = "ID")
    private Integer id;
    @TableField("USERNAME")
    private String username;
    private String loginName;
}