java.sql.ResultSet.wasNull()方法的使用及代码示例

x33g5p2x  于2022-01-28 转载在 其他  
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本文整理了Java中java.sql.ResultSet.wasNull方法的一些代码示例，展示了ResultSet.wasNull的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。ResultSet.wasNull方法的具体详情如下：
包路径：java.sql.ResultSet
类名称：ResultSet
方法名：wasNull

ResultSet.wasNull介绍

[英]Determines whether the last column read from this ResultSetcontained SQL NULL.
[中]确定从此ResultSetcontained SQL中读取的最后一列是否为空。

代码示例

代码示例来源：origin: stackoverflow.com

int iVal;
ResultSet rs = magicallyAppearingStmt.executeQuery(query);
if (rs.next()) {
  iVal = rs.getInt("ID_PARENT");
  if (rs.wasNull()) {
    // handle NULL field value
  }
}

代码示例来源：origin: dropwizard/dropwizard

@Override
public OptionalInt mapColumn(ResultSet r, int columnNumber, StatementContext ctx) throws SQLException {
  final int value = r.getInt(columnNumber);
  return r.wasNull() ? OptionalInt.empty() : OptionalInt.of(value);
}

代码示例来源：origin: SonarSource/sonarqube

@CheckForNull
public static Long getLong(ResultSet rs, String columnName) throws SQLException {
 long l = rs.getLong(columnName);
 return rs.wasNull() ? null : l;
}

代码示例来源：origin: apache/drill

@Test
public void testGetNonprimitiveTypeNullAsOwnType() throws Exception {
 final ResultSet rs = statement.executeQuery(
   "SELECT CAST( NULL AS VARCHAR ) FROM INFORMATION_SCHEMA.CATALOGS" );
 assertTrue( rs.next() );
 assertThat( "getString(...) for NULL", rs.getString( 1 ), nullValue() );
 assertThat( "wasNull", rs.wasNull(), equalTo( true ) );
}

代码示例来源：origin: apache/drill

@Test
public void testGetBooleanGetsFalse() throws Exception {
 ResultSet rs =
   statement.executeQuery( "SELECT FALSE FROM INFORMATION_SCHEMA.CATALOGS" );
 rs.next();
 assertThat( "getBoolean(...) for FALSE", rs.getBoolean( 1 ), equalTo( false ) );
 assertThat( "wasNull", rs.wasNull(), equalTo( false ) );
}

代码示例来源：origin: alibaba/druid

out.print(rs.getString(columnIndex));
} else if (type == Types.DATE) {
  Date date = rs.getDate(columnIndex);
  if (rs.wasNull()) {
    out.print("null");
  } else {
  if (rs.wasNull()) {
    out.print("null");
  } else {
  if (rs.wasNull()) {
    out.print("null");
  } else {
  if (rs.wasNull()) {
    out.print("null");
  } else {
  if (rs.wasNull()) {
    out.print("null");
  } else {
  int value = rs.getInt(columnIndex);
  if (rs.wasNull()) {
    out.print("null");
  } else {
  long value = rs.getLong(columnIndex);

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldThrowOnPropertyTypeWithoutRegisteredMapper() throws Exception {
  mockColumns("longField", "valueTypeField");
  when(resultSet.getLong(1)).thenReturn(123L);
  when(resultSet.getObject(2)).thenReturn(new Object());
  when(resultSet.wasNull()).thenReturn(false);
  assertThatThrownBy(() -> mapper.map(resultSet, ctx)).isInstanceOf(IllegalArgumentException.class);
}

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldUseRegisteredMapperForUnknownPropertyType() throws Exception {
  handle.registerColumnMapper(new ValueTypeMapper());
  mockColumns("longField", "valueTypeField");
  when(resultSet.getLong(1)).thenReturn(123L);
  when(resultSet.getString(2)).thenReturn("foo");
  when(resultSet.wasNull()).thenReturn(false);
  SampleBean sampleBean = mapper.map(resultSet, ctx);
  Long expected = 123L;
  assertThat(sampleBean.getLongField()).isEqualTo(expected);
  assertThat(sampleBean.getValueTypeField()).isEqualTo(ValueType.valueOf("foo"));
}

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldThrowOnProtectedSetter() throws Exception {
  mockColumns("protectedStringField");
  String expected = "string";
  when(resultSet.getString(1)).thenReturn(expected);
  when(resultSet.wasNull()).thenReturn(false);
  assertThatThrownBy(() -> mapper.map(resultSet, ctx)).isInstanceOf(IllegalArgumentException.class);
}

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldThrowOnPackagePrivateSetter() throws Exception {
  mockColumns("packagePrivateIntField");
  when(resultSet.getInt(1)).thenReturn(200);
  when(resultSet.wasNull()).thenReturn(false);
  assertThatThrownBy(() -> mapper.map(resultSet, ctx)).isInstanceOf(IllegalArgumentException.class);
}

代码示例来源：origin: SonarSource/sonarqube

@CheckForNull
public String getNullableString(int columnIndex) throws SQLException {
 String s = rs.getString(columnIndex);
 return rs.wasNull() ? null : s;
}

代码示例来源：origin: apache/hive

System.out.print("\n");
 for(Column c : row.getColumns()) {
  String avg = String.format("%.2f", rs.getDouble(4 + i*cc));
  if (rs.wasNull())
   avg = "null";
  String stddev = String.format("%.2f", rs.getDouble(7 + i*cc));
  if (rs.wasNull())
   stddev = "null";
  String p05 = String.format("%.2f", rs.getDouble(8 + i*cc));
  if (rs.wasNull())
   p05 = "null";
  String p25 = String.format("%.2f", rs.getDouble(9 + i*cc));
  if (rs.wasNull())
   p25 = "null";
  String p50 = String.format("%.2f", rs.getDouble(10 + i*cc));
  if (rs.wasNull())
   p50 = "null";
  String p75 = String.format("%.2f", rs.getDouble(11 + i*cc));
  if (rs.wasNull())
   p75 = "null";
  String p95 = String.format("%.2f", rs.getDouble(12 + i*cc));
  if (rs.wasNull())
   p95 = "null";
  System.out.print(String.format(fmt, c.getName(), c.getType(), cntRows, rs.getString(2 + i*cc),
    rs.getString(3 + i*cc), avg, rs.getString(5 + i*cc), rs.getString(6 + i*cc),
    stddev, p05, p25, p50, p75, p95));
  i++;

代码示例来源：origin: oblac/jodd

@Override
  public LocalTime get(final ResultSet rs, final int index, final int dbSqlType) throws SQLException {
    if (dbSqlType == Types.VARCHAR) {
      String string = rs.getString(index);
      if (string == null) {
        return null;
      }
      return LocalTime.parse(string);
    }

    long time = rs.getLong(index);

    if (time == 0 && rs.wasNull()) {
      return null;
    }
    return LocalTime.ofSecondOfDay(time);
  }
}

代码示例来源：origin: deeplearning4j/nd4j

/**
 * Load an ndarray blob given an id
 *
 * @param id the id to load
 * @return the blob
 */
@Override
public Blob loadForID(String id) throws SQLException {
  Connection c = dataSource.getConnection();
  PreparedStatement preparedStatement = c.prepareStatement(loadStatement());
  preparedStatement.setString(1, id);
  ResultSet r = preparedStatement.executeQuery();
  if (r.wasNull() || !r.next()) {
    return null;
  } else {
    Blob first = r.getBlob(2);
    return first;
  }
}

代码示例来源：origin: apache/drill

@Test
public void testGetPrimitiveTypeNullAsOwnType() throws Exception {
 final ResultSet rs = statement.executeQuery(
   "SELECT CAST( NULL AS INTEGER ) FROM INFORMATION_SCHEMA.CATALOGS" );
 assertTrue( rs.next() );
 assertThat( "getInt(...) for NULL", rs.getInt( 1 ), equalTo( 0 ) );
 assertThat( "wasNull", rs.wasNull(), equalTo( true ) );
}

代码示例来源：origin: apache/drill

@Test
public void testGetBooleanGetsNull() throws Exception {
 ResultSet rs = statement.executeQuery(
   "SELECT CAST( NULL AS BOOLEAN ) FROM INFORMATION_SCHEMA.CATALOGS" );
 rs.next();
 assertThat( "getBoolean(...) for BOOLEAN NULL", rs.getBoolean( 1 ), equalTo( false ) );
 assertThat( "wasNull", rs.wasNull(), equalTo( true ) );
}

代码示例来源：origin: zendesk/maxwell

protected List<RecoveryInfo> getAllRecoveryInfos(Connection c) throws SQLException {
  PreparedStatement s = c.prepareStatement("SELECT * from `positions` where client_id = ? order by last_heartbeat_read DESC");
  s.setString(1, clientID);
  ResultSet rs = s.executeQuery();
  ArrayList<RecoveryInfo> recoveries = new ArrayList<>();
  while ( rs.next() ) {
    Long server_id = rs.getLong("server_id");
    String gtid = gtidMode ? rs.getString("gtid_set") : null;
    Position position = new Position(
      BinlogPosition.at(gtid,
        rs.getLong("binlog_position"),
        rs.getString("binlog_file")
      ), rs.getLong("last_heartbeat_read"));
    if ( rs.wasNull() ) {
      LOGGER.warn("master recovery is ignoring position with NULL heartbeat");
    } else {
      recoveries.add(new RecoveryInfo(position, server_id, clientID));
    }
  }
  return recoveries;
}

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldThrowOnPropertyTypeWithoutRegisteredMapper() throws Exception {
  mockColumns("longField", "valueTypeField");
  when(resultSet.getLong(1)).thenReturn(123L);
  when(resultSet.getObject(2)).thenReturn(new Object());
  when(resultSet.wasNull()).thenReturn(false);
  assertThatThrownBy(() -> mapper.map(resultSet, ctx)).isInstanceOf(IllegalArgumentException.class);
}

代码示例来源：origin: jdbi/jdbi

@Test
public void shouldUseRegisteredMapperForUnknownPropertyType() throws Exception {
  handle.registerColumnMapper(new ValueTypeMapper());
  mockColumns("longField", "valueTypeField");
  Long expected = 123L;
  when(resultSet.getLong(1)).thenReturn(expected);
  when(resultSet.getString(2)).thenReturn("foo");
  when(resultSet.wasNull()).thenReturn(false);
  SampleBean sampleBean = mapper.map(resultSet, ctx);
  assertThat(sampleBean.getLongField()).isEqualTo(expected);
  assertThat(sampleBean.getValueTypeField()).isEqualTo(ValueType.valueOf("foo"));
}

代码示例来源：origin: SonarSource/sonarqube

@CheckForNull
public static String getString(ResultSet rs, String columnName) throws SQLException {
 String s = rs.getString(columnName);
 return rs.wasNull() ? null : s;
}

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