1、使用JdbcTemplate的execute()方法执行SQL语句
[Java] 纯文本查看 复制代码 jdbcTemplate.execute("CREATE TABLE USER (user_id integer, name varchar(100))");
2、如果是UPDATE或INSERT,可以用update()方法。
[Java] 纯文本查看 复制代码 jdbcTemplate.update("INSERT INTO USER VALUES('"
+ user.getId() + "', '"
+ user.getName() + "', '"
+ user.getSex() + "', '"
+ user.getAge() + "')");
3、带参数的更新
[Java] 纯文本查看 复制代码 jdbcTemplate.update("UPDATE USER SET name = ? WHERE user_id = ?", new Object[] {name, id});
jdbcTemplate.update("INSERT INTO USER VALUES(?, ?, ?, ?)",
new Object[] {user.getId(), user.getName(), user.getSex(), user.getAge()});
4、使用JdbcTemplate进行查询时,使用queryForXXX()等方法。查询单列或者列表。
[Java] 纯文本查看 复制代码 int count = jdbcTemplate.queryForInt("SELECT COUNT(*) FROM USER");
String name = (String) jdbcTemplate.queryForObject("SELECT name FROM USER WHERE user_id = ?", new Object[] {id}, java.lang.String.class);
List rows = jdbcTemplate.queryForList("SELECT * FROM USER");
List rows = jdbcTemplate.queryForList("SELECT * FROM USER");
Iterator it = rows.iterator();
while(it.hasNext()) {
Map userMap = (Map) it.next();
System.out.print(userMap.get("user_id") + "\t");
System.out.print(userMap.get("name") + "\t");
System.out.print(userMap.get("sex") + "\t");
System.out.println(userMap.get("age") + "\t");
}
JdbcTemplate将我们使用的JDBC的流程封装起来,包括了异常的捕捉、SQL的执行、查询结果的转换等等。spring大量使用Template Method模式来封装固定流程的动作,XXXTemplate等类别都是基于这种方式的实现。 除了大量使用Template Method来封装一些底层的操作细节,spring也大量使用callback方式类回调相关类别的方法以提供JDBC相关类别的功能,使传统的JDBC的使用者也能清楚了解spring所提供的相关封装类别方法的使用。
JDBC的PreparedStatement [Java] 纯文本查看 复制代码 final String id = user.getId();
final String name = user.getName();
final String sex = user.getSex() + "";
final int age = user.getAge();
jdbcTemplate.update("INSERT INTO USER VALUES(?, ?, ?, ?)",
new PreparedStatementSetter() {
public void setValues(PreparedStatement ps) throws SQLException {
ps.setString(1, id);
ps.setString(2, name);
ps.setString(3, sex);
ps.setInt(4, age);
}
});
final User user = new User();
jdbcTemplate.query("SELECT * FROM USER WHERE user_id = ?",
new Object[] {id},
new RowCallbackHandler() {
public void processRow(ResultSet rs) throws SQLException {
user.setId(rs.getString("user_id"));
user.setName(rs.getString("name"));
user.setSex(rs.getString("sex").charAt(0));
user.setAge(rs.getInt("age"));
}
});
// 注意在Spring2.0前后是有区别的,后改为RowMapperResultSetExtractor
class UserRowMapper implements RowMapper {
public Object mapRow(ResultSet rs, int index) throws SQLException {
User user = new User();
user.setId(rs.getString("user_id"));
user.setName(rs.getString("name"));
user.setSex(rs.getString("sex").charAt(0));
user.setAge(rs.getInt("age"));
return user;
}
}
public List findAllByRowMapperResultReader() {
String sql = "SELECT * FROM USER";
return jdbcTemplate.query(sql, new RowMapperResultReader(new UserRowMapper()));
}
在getUser(id)里面使用UserRowMapper [Java] 纯文本查看 复制代码 public User getUser(final String id) throws DataAccessException {
String sql = "SELECT * FROM USER WHERE user_id=?";
final Object[] params = new Object[] { id };
List list = jdbcTemplate.query(sql, params, new RowMapperResultReader(new UserRowMapper()));
return (User) list.get(0);
}
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