mybatis注解开发-动态SQL

实体类以及表结构

在mybatis-config.xml中注册mapper接口

--------------------------

动态查询@SelectProvider

EmployeeMapper接口

package Intefaceproxy.Dyno;

import java.util.List;
import java.util.Map;
import org.apache.ibatis.annotations.SelectProvider;
import model.Employee;

public interface EmployeeMapper {
    //动态查询  type:指定一个类    method:使用这个类中的selectWhitParamSql方法返回的sql字符串  作为查询的语句
    @SelectProvider(type=Intefaceproxy.Dyno.EmployeeDynaSqlProvider.class,method="selectWhitParamSql")
    List<Employee> selectWithParam(Map<String,Object> param);
}

返回sql语句的类

package Intefaceproxy.Dyno;

import java.util.Map;

import org.apache.ibatis.jdbc.SQL;

public class EmployeeDynaSqlProvider {
    //方法中的关键字是区分大小写的  SQL SELECT WHERE
    //该方法会根据传递过来的map中的参数内容  动态构建sql语句
    public String selectWhitParamSql(Map<String, Object> param) {
        return new SQL() {
            {
                SELECT("*");
                FROM("tb_employee");
                if (param.get("id")!=null) {
                    WHERE("id=#{id}");
                }
                if(param.get("loginname")!=null) {
                    WHERE("loginname=#{loginname}");
                }
                if(param.get("password")!=null) {
                    WHERE("password=#{password}");
                }
                if(param.get("name")!=null) {
                    WHERE("name=#{name}");
                }
                if(param.get("sex")!=null) {
                    WHERE("sex=#{sex}");
                }
                if(param.get("age")!=null) {
                    WHERE("age=#{age}");
                }
                if(param.get("phone")!=null) {
                    WHERE("phone=#{phone}");
                }
                if(param.get("sal")!=null) {
                    WHERE("sal=#{sal}");
                }
                if(param.get("state")!=null) {
                    WHERE("state=#{state}");
                }
            }

        }.toString();
    }
}

测试：

当然也可以传递employee对象

接口：

	//传递employee对象
	@SelectProvider(type=Intefaceproxy.Dyno.EmployeeDynaSqlProvider.class,method="selectWhitEmployeeSql")
	List<Employee>selectWithEmployee(Employee employee);

返回sql的类

//selectWhitEmployeeSql
	public String selectWhitEmployeeSql(Employee employee) {
		return new SQL() {
			{
				SELECT("*");
				FROM("tb_employee");
				if (employee.getId()!=null) {
					WHERE("id=#{id}");
				}
				if(employee.getLoginname()!=null) {
					WHERE("loginname=#{loginname}");
				}
				if(employee.getPassword()!=null) {
					WHERE("password=#{password}");
				}
				if(employee.getName()!=null) {
					WHERE("name=#{name}");
				}
				if(employee.getSex()!=null) {
					WHERE("sex=#{sex}");
				}
			}
		}.toString();
	}

测试：

------------------------------

动态插入@InsertProvider

//动态插入
	@InsertProvider(type=Intefaceproxy.Dyno.EmployeeDynaSqlProvider.class,method="insertEmployeeSql")
	@Options(useGeneratedKeys=true,keyProperty="id")
	int insertEmployee(Employee employee);

//insertEmployeeSql
	public String insertEmployeeSql(Employee employee) {
		return new SQL() {
			{
				INSERT_INTO("tb_employee");
				if(employee.getLoginname()!=null) {
					VALUES("loginname","#{loginname}");
				}
				if(employee.getPassword()!=null) {
					VALUES("password", "#{password}");
				}
				if(employee.getName()!=null) {
					VALUES("name", "#{name}");
				}
				if(employee.getSex()!=null) {
					VALUES("sex", "#{sex}");
				}
				if(employee.getAge()!=null) {
					VALUES("age", "#{age}");
				}
				if(employee.getPhone()!=null) {
					VALUES("phone", "#{phone}");
				}
				if(employee.getSal()!=null) {
					VALUES("sal", "#{sal}");
				}
				if(employee.getState()!=null) {
					VALUES("state", "#{state}");
				}
			}
		}.toString();
	}

测试：

-------------------------

@UpdateProvider

//动态更新
	@UpdateProvider(type=Intefaceproxy.Dyno.EmployeeDynaSqlProvider.class,method="updateEmployeeSql")
	void updateEmployee(Employee employee);

//updateEmployeeSql
	public String updateEmployeeSql(Employee employee) {
		return new SQL() {
			{
				UPDATE("tb_employee");
				if(employee.getLoginname()!=null) {
					SET("loginname=#{loginname}");
				}
				if(employee.getPassword()!=null) {
					SET("password=#{password}");
				}
				if(employee.getName()!=null) {
					SET("name=#{name}");
				}
				if(employee.getSex()!=null) {
					SET("sex=#{sex}");
				}
				if(employee.getAge()!=null) {
					SET("age=#{age}");
				}
				if(employee.getPhone()!=null) {
					SET("phone=#{phone}");
				}
				if(employee.getSal()!=null) {
					SET("sal=#{sal}");
				}
				if(employee.getState()!=null) {
					SET("state=#{state}");
				}
				WHERE("id=#{id}");
			}
		}.toString();
	}

测试：

----------------------------

@DeleteProvider

	//动态删除
	@DeleteProvider(type=Intefaceproxy.Dyno.EmployeeDynaSqlProvider.class,method="deleteEmployeeSql")
	void deleteEmployee(Employee employee);

	//deleteEmployeeSql
	public String deleteEmployeeSql(Employee employee) {
		return new SQL() {
			{
				DELETE_FROM("tb_employee");
				if(employee.getLoginname()!=null) {
					WHERE("loginname=#{loginname}");
				}
				if(employee.getPassword()!=null) {
					WHERE("password=#{password}");
				}
				if(employee.getName()!=null) {
					WHERE("name=#{name}");
				}
			}
		}.toString();
	}

　测试：

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原文地址：https://www.cnblogs.com/Joke-Jay/p/8524722.html