H2數據庫用來做單測數據庫，可以自定義初始化數據，不用擔心數據庫內容更改造成單測跑不過問題，不過H2數據庫跟實際使用的Mysql還是有一定區別。

1. H2數據庫不支持Mysql的批量更新功能，支持批量插入

--批量更新（H2不支持）
  <update id="increaseBatch"  parameterType="java.util.List">
        <foreach collection="list" item="item" index="index" open="" close="" separator=";">
            update
 
 product
            <set>
                quantity = quantity + #{item.updateQuantity}, modify_time = #{item.modifyTime}
            </set>
            where id = #{item.productId}
        </foreach>
    </update>

--批量插入（H2支持）
<insert id="insertItems" keyProperty="id" parameterType=
 
"java.util.List" useGeneratedKeys="true">
        <selectKey keyProperty="id" order="AFTER" resultType="long">
            SELECT LAST_INSERT_ID()
        </selectKey>
        INSERT INTO bill_item(
        bill_id,product_id,product_name,product_quantity,product_quantity_after,product
 
_price,product_amount)
        VALUES
        <foreach close="" collection="list" index="index" item="item" open="" separator=",">
            (
            #{item.billId},#{item.productId},#{item.productName},#{item.productQuantity},
            #{item.productQuantityAfter},#{item.productPrice},#{item.productAmount})
        </foreach>
    </insert>

2. H2數據庫不支持Mysql的replace into 語法

3. H2數據庫初始化時不允許出現相同的UK

    <jdbc:embedded-database id="dataSource" type="H2">
        <jdbc:script location="classpath:H2_TYPE.sql"/>
        <jdbc:script location="classpath:INIT_TABLE.sql"/>
        <jdbc:script location="classpath:INIT_DATA.sql"/>
    </jdbc:embedded-database>

INIT_TABLE.sql

-- 表A
CREATE TABLE `table_A` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT ‘自增主鍵‘,
  `bill_no` varchar(45) DEFAULT NULL COMMENT ‘單號‘,
  `bill_type` tinyint(4) unsigned NOT NULL DEFAULT ‘0‘ COMMENT ‘單據類別‘,
  `created_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘創建時間‘,
  `modify_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘修改時間‘,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_bill_type_bill_no` (`bill_type`,`bill_no`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;

--表A
CREATE TABLE `table_B` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT ‘自增主鍵‘,
  `bill_no` varchar(45) DEFAULT NULL COMMENT ‘單號‘,
  `bill_type` tinyint(4) unsigned NOT NULL DEFAULT ‘0‘ COMMENT ‘單據類別‘,
  `created_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘創建時間‘,
  `modify_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘修改時間‘,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_bill_type_bill_no` (`bill_type`,`bill_no`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;

運行結果：

Caused by: org.h2.jdbc.JdbcSQLException: Constraint "uk_bill_type_bill_no" already exists; 
SQL statement:CREATE TABLE `table_B` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT ‘自增主鍵‘,
  `bill_no` varchar(45) DEFAULT NULL COMMENT ‘單號‘,
  `bill_type` tinyint(4) unsigned NOT NULL DEFAULT ‘0‘ COMMENT ‘單據類別‘,
  `created_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘創建時間‘,
  `modify_time` datetime NOT NULL DEFAULT ‘1000-01-01 00:00:00‘ COMMENT ‘修改時間‘,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_bill_type_bill_no` (`bill_type`,`bill_no`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;

H2數據庫做單測數據庫時踩到的坑