MyBatis绑定Mapper接口参数到Mapper映射文件sql语句参数

一、设置paramterType

1.类型为基本类型

a.代码示例

映射文件：

<select id="findShopCartInfoById" parameterType="int"
    resultType="ShopCart">
    select*
    from shopcart
    where shopcartid = #{id}
</select>

Mapper接口：

ShopCart findShopCartInfoById(int id);

测试代码：

ShopCartMapper scm = sqlSession.getMapper(ShopCartMapper.class);
ShopCart shopCart = scm.findShopCartInfoById(14);

2.类型为对象类

映射文件：

<insert id="addShopCartInfo" parameterType="ShopCart">
    insert into
    shopcart(buyerid,bookid,amount,price,status)
    values(#{buyerId},#{bookId},#{amount},#{price},#{status})
</insert>

Mapper接口：

int addShopCartInfo(ShopCart shopCart);

ShopCart.java

package com.yh.entity;

public class ShopCart {
    private int shopCartId;
    private int buyerId;
    private int bookId;
    private short amount;
    private float price;
    private short status;
    private Book book;

    public ShopCart() {
    }

    public ShopCart(int buyerId, int bookId, int amount, int price, int status) {
        this.buyerId = buyerId;
        this.bookId = bookId;
        this.amount = (short) amount;
        this.price = price;
        this.status = (short) status;
    }

    public int getBuyerId() {
        return buyerId;
    }

    public void setBuyerId(int buyerId) {
        this.buyerId = buyerId;
    }

    public int getBookId() {
        return bookId;
    }

    public void setBookId(int bookId) {
        this.bookId = bookId;
    }

    public short getAmount() {
        return amount;
    }

    public void setAmount(short amount) {
        this.amount = amount;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    public short getStatus() {
        return status;
    }

    public void setStatus(short status) {
        this.status = status;
    }

    public Book getBook() {
        return book;
    }

    public void setBook(Book book) {
        this.book = book;
    }

    public int getShopCartId() {
        return shopCartId;
    }

    public void setShopCartId(int shopCartId) {
        this.shopCartId = shopCartId;
    }

}

测试代码：

@ResponseBody
@RequestMapping(value = "/addInfo", produces = "application/json; charset=utf-8", method = RequestMethod.GET)
public String addInfo(HttpSession session, ShopCart shopCart) {
    this.init();
    shopCart.setBuyerId((int) session.getAttribute("userId"));
    ShopCartMapper scm = sqlSession.getMapper(ShopCartMapper.class);int result = scm.addShopCartInfo(shopCart);
    this.destroy();
    return result != 0 ? "添加成功" : "添加失败";
}

二、注解Mapper接口中方法参数

设置Mapper接口中@Param注释的值和映射文件中sql语句中的“参数名”相同。

映射文件：

<update id="changeAmount">
    update shopcart set
    amount=#{amount} where shopcartid
    = #{shopCartId}
</update>

Mapper接口：

int changeAmount(@Param("amount") int amount, @Param("shopCartId") int shopCartId);

测试代码：

@ResponseBody
@RequestMapping(value = "/changeAmount", produces = "application/json;charset=utf-8")
public String changeAmount(@RequestParam(value = "amount") String amount,
        @RequestParam(value = "shopCartId") String shopCartId) {
    this.init();
    ShopCartMapper scm = sqlSession.getMapper(ShopCartMapper.class);
    int result = scm.changeAmount(Integer.valueOf(amount), Integer.valueOf(shopCartId));
    this.destroy();
    return result != 0 ? "修改成功" : "修改失败";
}