⬇参考代码：demo1

单个参数

CustomerMapper.java\text {CustomerMapper.java}

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Customer selectCustomerById(Integer id);

CustomerMapper.xml\text {CustomerMapper.xml}

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<!--    <select id="selectCustomerById" resultMap="CustomerMap">-->
<!--        SELECT *-->
<!--        FROM customers-->
<!--        WHERE CustomerID = '${id}'-->
<!--    </select>-->
<select id="selectCustomerById" resultMap="CustomerMap">
    SELECT *
    FROM customers
    WHERE CustomerID = #{id}
</select>

测试 ⇒\Rightarrow

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@Test
public void selectCustomerById() {
    SqlSession sqlSession = SqlSessionUtils.getSqlSession();
    CustomerMapper customerMapper = sqlSession.getMapper(CustomerMapper.class);
    Customer customer = customerMapper.selectCustomerById(1);
    System.out.println(customer);
}

多个参数

1⃣arg

CustomerMapper.java\text {CustomerMapper.java}

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Customer selectCustomerByPostalCodeAndCountry1(String postalCode, String country);

CustomerMapper.xml\text {CustomerMapper.xml}

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<select id="selectCustomerByPostalCodeAndCountry1" resultMap="CustomerMap">
    SELECT *
    FROM customers
    WHERE PostalCode = #{arg0}
      AND Country = #{arg1}
</select>

测试 ⇒\Rightarrow

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@Test
public void selectCustomerByPostalCodeAndCountry1() {
    SqlSession sqlSession = SqlSessionUtils.getSqlSession();
    CustomerMapper customerMapper = sqlSession.getMapper(CustomerMapper.class);
    Customer customer = customerMapper.selectCustomerByPostalCodeAndCountry1("98034", "USA");
    System.out.println(customer);
}

2⃣param

CustomerMapper.java\text {CustomerMapper.java}

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Customer selectCustomerByPostalCodeAndCountry1(String postalCode, String country);

CustomerMapper.xml\text {CustomerMapper.xml}

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<select id="selectCustomerByPostalCodeAndCountry1" resultMap="CustomerMap">
    SELECT *
    FROM customers
    WHERE PostalCode = #{param1}
      AND Country = #{param2}
</select>

测试 ⇒\Rightarrow

同上。

3⃣键值对

CustomerMapper.java\text {CustomerMapper.java}

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Customer selectCustomerByPostalCodeAndCountry2(Map<String, String> postalCodeAndCountry);

CustomerMapper.xml\text {CustomerMapper.xml}

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<select id="selectCustomerByPostalCodeAndCountry2" resultMap="CustomerMap">
    SELECT *
    FROM customers
    WHERE PostalCode = #{PostalCode}
      AND Country = #{Country}
</select>

测试 ⇒\Rightarrow

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@Test
public void selectCustomerByPostalCodeAndCountry2() {
    SqlSession sqlSession = SqlSessionUtils.getSqlSession();
    CustomerMapper customerMapper = sqlSession.getMapper(CustomerMapper.class);
    Map<String, String> postalCodeAndCountry = new HashMap<>();
    postalCodeAndCountry.put("PostalCode", "98034");
    postalCodeAndCountry.put("Country", "USA");
    Customer customer = customerMapper.selectCustomerByPostalCodeAndCountry2(postalCodeAndCountry);
    System.out.println(customer);
}

4⃣@Param注解

CustomerMapper.java\text {CustomerMapper.java}

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Customer selectCustomerByPostalCodeAndCountry3(@Param("PostalCode") String postalCode, @Param("Country") String country);

CustomerMapper.xml\text {CustomerMapper.xml}

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<select id="selectCustomerByPostalCodeAndCountry3" resultMap="CustomerMap">
    SELECT *
    FROM customers
    WHERE PostalCode = #{PostalCode}
      AND Country = #{Country}
</select>

测试 ⇒\Rightarrow

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@Test
public void selectCustomerByPostalCodeAndCountry3() {
    SqlSession sqlSession = SqlSessionUtils.getSqlSession();
    CustomerMapper customerMapper = sqlSession.getMapper(CustomerMapper.class);
    Customer customer = customerMapper.selectCustomerByPostalCodeAndCountry3("98034", "USA");
    System.out.println(customer);
}