Java基础学习-MySQL连接

2021-12-15 19:10:59 浏览数 (2)

学习了一下怎么连接数据库操作数据,遇见了一些问题,记录一下

报错:

代码语言:javascript复制
Exception in thread "main" com.mysql.cj.jdbc.exceptions.MysqlDataTruncation: Data truncation: Incorrect date value: '1995' for column 'submission_date' at row 1
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:104)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1098)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1046)
    at com.mysql.cj.jdbc.ClientPreparedStatement.executeLargeUpdate(ClientPreparedStatement.java:1371)
    at com.mysql.cj.jdbc.CallableStatement.executeLargeUpdate(CallableStatement.java:2545)
    at com.mysql.cj.jdbc.CallableStatement.executeUpdate(CallableStatement.java:901)
    at JdbcDemo.main(JdbcDemo.java:13)

查了半天发现sql语句添加得值没有加单引号

错误代码:

代码语言:javascript复制
 String sql2 ="INSERT INTO runoob_tbl(runoob_title,runoob_author, submission_date)VALUES(1,2,2021-12-14);";

修改过后:

代码语言:javascript复制
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class JdbcDemo {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        Class.forName("com.mysql.cj.jdbc.Driver");
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test_frank","root","root");

        String sql2 ="INSERT INTO runoob_tbl(runoob_title,runoob_author, submission_date)VALUES('1','2','2021-12-14');";
        PreparedStatement statement = connection.prepareCall(sql2);
        statement.executeUpdate();
        statement.close();
        connection.close();
    }
}

代码优化:各种异常往出抛

代码语言:javascript复制
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class JdbcDemo {
    public static void main(String[] args)  {
        Connection connection = null;
        PreparedStatement statement = null;
        String sql2 ="INSERT INTO runoob_tbl(runoob_title,runoob_author, submission_date)VALUES('1','2','2021-12-14');";
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test_frank","root","root");
            statement = connection.prepareCall(sql2);
            statement.executeUpdate();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        finally {
            try {
                if(statement != null){
                    statement.close();
                }
                if(connection != null){
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

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