JAVA中直接执行sql语句示例

代码：

import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Test {
          
   

    //执行select
    private List<Map<String, Object>> executeGet(String schema, String sql) throws SQLException {
          
   
        Statement statement = null;
        ResultSet resultSet = null;
        try {
          
   
            Connection connection = getConnection();
            connection.setCatalog(schema);
            statement = connection.createStatement();
            resultSet = statement.executeQuery(sql);
            ResultSetMetaData metaData = resultSet.getMetaData();
            List<Map<String, Object>> resultList = new ArrayList<>();
            while (resultSet.next()) {
          
   
                Map<String, Object> dataMap = new HashMap<>();
                for (int i = 1; i <= metaData.getColumnCount(); i++) {
          
   
                    dataMap.put(metaData.getColumnLabel(i), resultSet.getObject(i));
                }                resultList.add(dataMap);
            }
            return resultList;
        } catch (Exception e) {
          
   
            throw e;
        } finally {
          
   
            try {
          
   
                if (resultSet != null) {
          
   
                    resultSet.close();
                }
                if (statement != null) {
          
   
                    statement.close();
                }
            } catch (SQLException e) {
          
   

            }
        }
    }

    //执行update，insert，delete
    private int executeUpdate(String schema, String sql) throws SQLException {
          
   
        Statement statement = null;
        try {
          
   
            Connection connection = getConnection();
            connection.setCatalog(schema);
            statement = connection.createStatement();
            return statement.executeUpdate(sql);
        } catch (Exception e) {
          
   
            throw e;
        } finally {
          
   
            try {
          
   
                if (statement != null) {
          
   
                    statement.close();
                }
            } catch (SQLException e) {
          
   

            }
        }
    }

	//将结果集转换为对象
    public static <T> List<T> parserDbo(List<Map<String, Object>> dboMapList, Class<T> dboClass, boolean canEmpty) throws Exception {
          
   
        if (CollectionUtil.isEmpty(dboMapList)) {
          
   
            if (!canEmpty) {
          
   
                throw new Exception("");
            }
            dboMapList = new ArrayList<>();
        }
        List<T> resultList = new ArrayList<>();
        for (Map<String, Object> dboMap : dboMapList) {
          
   
            resultList.add(BeanUtil.mapToBean(dboMap, dboClass, false));
        }
        return resultList;
    }


}

注意：BeanUtil.mapToBean这个方法，需要导入以下依赖

<dependency>
      <groupId>cn.hutool</groupId>
      <artifactId>hutool-all</artifactId>
      <version>5.7.4</version>
    </dependency>