本文整理了Java中org.skife.jdbi.v2.Query.first方法的一些代码示例，展示了Query.first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。Query.first方法的具体详情如下：
包路径：org.skife.jdbi.v2.Query
类名称：Query
方法名：first

Query.first介绍

[英]Executes the select.

Specifies a maximum of one result on the JDBC statement, and map that one result as the return value, or return null if there is nothing in the results
[中]执行选择。
在JDBC语句中指定最多一个结果，并将该结果映射为返回值，如果结果中没有任何内容，则返回null

代码示例

代码示例来源：origin: apache/incubator-druid

@Override
 public Timestamp withHandle(Handle handle)
 {
  final String query = StringUtils.format(
    "SELECT MAX(%s) FROM %s",
    tsColumn, table
  );
  return handle
    .createQuery(query)
    .map(TimestampMapper.FIRST)
    .first();
 }
}

代码示例来源：origin: apache/incubator-druid

@Override
 public Optional<EntryType> withHandle(Handle handle) throws Exception
 {
  byte[] res = handle.createQuery(
    StringUtils.format("SELECT payload FROM %s WHERE id = :id", entryTable)
  )
            .bind("id", entryId)
            .map(ByteArrayMapper.FIRST)
            .first();
  return Optional.fromNullable(
    res == null ? null : jsonMapper.readValue(res, entryType)
  );
 }
}

代码示例来源：origin: apache/incubator-druid

@Override
 public Optional<StatusType> withHandle(Handle handle) throws Exception
 {
  byte[] res = handle.createQuery(
    StringUtils.format("SELECT status_payload FROM %s WHERE id = :id", entryTable)
  )
            .bind("id", entryId)
            .map(ByteArrayMapper.FIRST)
            .first();
  return Optional.fromNullable(
    res == null ? null : jsonMapper.readValue(res, statusType)
  );
 }
}

代码示例来源：origin: apache/incubator-druid

@Override
@Nullable
public TaskInfo<EntryType, StatusType> getTaskInfo(String entryId)
{
 return connector.retryWithHandle(handle -> {
  final String query = StringUtils.format(
    "SELECT id, status_payload, payload, datasource, created_date FROM %s WHERE id = :id",
    entryTable
  );
  return handle.createQuery(query)
         .bind("id", entryId)
         .map(taskInfoMapper)
         .first();
 });
}

代码示例来源：origin: apache/incubator-druid

@Override
public boolean tableExists(Handle handle, String tableName)
{
 String databaseCharset = handle
   .createQuery("SELECT @@character_set_database")
   .map(StringMapper.FIRST)
   .first();
 if (!databaseCharset.startsWith("utf8")) {
  throw new ISE(
    "Druid requires its MySQL database to be created with an UTF8 charset, found `%1$s`. "
    + "The recommended charset is `utf8mb4`.",
    databaseCharset
  );
 } else if (!"utf8mb4".equals(databaseCharset)) {
  log.warn("The current database charset `%1$s` does not match the recommended charset `utf8mb4`", databaseCharset);
 }
 return !handle.createQuery("SHOW tables LIKE :tableName")
        .bind("tableName", tableName)
        .list()
        .isEmpty();
}

代码示例来源：origin: apache/incubator-druid

.createQuery(
  StringUtils.format(
    "SELECT %1$s FROM %2$s WHERE %3$s = :key",
.first();

代码示例来源：origin: apache/incubator-druid

.createQuery(
    StringUtils.format("SELECT COUNT(*) FROM %1$s WHERE %2$s = :key", tableName, keyColumn)
  .first();
if (count == 0) {
 handle.createStatement(

代码示例来源：origin: HubSpot/Singularity

@Override
public int getTaskIdHistoryCount(Optional<String> requestId, Optional<String> deployId, Optional<String> runId, Optional<String> host,
                 Optional<ExtendedTaskState> lastTaskStatus, Optional<Long> startedBefore, Optional<Long> startedAfter, Optional<Long> updatedBefore,
                 Optional<Long> updatedAfter) {
  final Map<String, Object> binds = new HashMap<>();
  final StringBuilder sqlBuilder = new StringBuilder(GET_TASK_ID_HISTORY_COUNT_QUERY);
  applyTaskIdHistoryBaseQuery(sqlBuilder, binds, requestId, deployId, runId, host, lastTaskStatus, startedBefore, startedAfter, updatedBefore, updatedAfter);
  final String sql = sqlBuilder.toString();
  LOG.trace("Generated sql for task search count: {}, binds: {}", sql, binds);
  final Query<Integer> query = getHandle().createQuery(sql).mapTo(Integer.class);
  for (Map.Entry<String, Object> entry : binds.entrySet()) {
    query.bind(entry.getKey(), entry.getValue());
  }
  return query.first();
}

代码示例来源：origin: rakam-io/rakam

private boolean hasMasterAccess(Handle handle, int project, int user) {
  return TRUE.equals(handle.createQuery("select user_id = :user or (select bool_or(master_permission) from web_user_api_key_permission p " +
      "join web_user_api_key a on (p.api_key_id = a.id) where p.user_id = :user and a.project_id = :project) from web_user_project where id = :project")
      .bind("user", user)
      .bind("project", project).map(BooleanMapper.FIRST)
      .first());
}

代码示例来源：origin: rakam-io/rakam

@Override
public InputStream getFile(int project, String slug, String file) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("SELECT data FROM custom_page WHERE project_id = :project AND slug = :slug")
        .bind("project", project)
        .bind("slug", slug)
        .map((i, resultSet, statementContext) -> {
          return new ByteArrayInputStream(((String) JsonHelper.read(resultSet.getString(1), Map.class)
              .get(file)).getBytes(UTF_8));
        }).first();
  }
}

代码示例来源：origin: rakam-io/rakam

public ProjectOwner getProjectOwner(int project) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("select web_user.id, web_user.email from web_user join web_user_project project on (project.user_id = web_user.id) where project.id = :id")
        .bind("id", project)
        .map((index, r, ctx) -> {
          return new ProjectOwner(r.getInt(1), r.getString(2));
        }).first();
  }
}

代码示例来源：origin: rakam-io/rakam

public String getUserStripeId(int id) {
  try (Handle handle = dbi.open()) {
    return handle
        .createQuery("SELECT stripe_id FROM web_user WHERE id = :id")
        .bind("id", id).map(StringMapper.FIRST).first();
  }
}

代码示例来源：origin: rakam-io/rakam

@Override
public <T> T getConfig(String project, String configName, Class<T> clazz) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("SELECT value FROM config WHERE project = :project AND name = :name")
        .bind("project", project)
        .bind("name", configName.toUpperCase(Locale.ENGLISH)).map((i, resultSet, statementContext) -> {
          return JsonHelper.read(resultSet.getString(1), clazz);
        }).first();
  }
}

代码示例来源：origin: rakam-io/rakam

@Override
public <T> T getConfig(String project, String configName, Class<T> clazz) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("SELECT value FROM config WHERE project = :project AND name = :name")
        .bind("project", project)
        .bind("name", configName.toUpperCase(Locale.ENGLISH)).map((i, resultSet, statementContext) -> {
          return JsonHelper.read(resultSet.getString(1), clazz);
        }).first();
  }
}

代码示例来源：origin: rakam-io/rakam

public Optional<WebUser> getUser(int id) {
  List<WebUser.Project> projectDefinitions;
  try (Handle handle = dbi.open()) {
    final Map<String, Object> data = handle
        .createQuery("SELECT id, name, email, read_only, created_at FROM web_user WHERE id = :id")
        .bind("id", id).first();
    if (data == null) {
      return Optional.empty();
    }
    String name = (String) data.get("name");
    String email = (String) data.get("email");
    Timestamp createdAt = (Timestamp) data.get("created_at");
    id = (int) data.get("id");
    projectDefinitions = getUserApiKeys(handle, id);
    return Optional.of(new WebUser(id, email, name,
        (Boolean) data.get("read_only"), createdAt.toInstant(), generateIntercomHash(email), projectDefinitions));
  }
}

代码示例来源：origin: rakam-io/rakam

public Optional<WebUser> getUserByEmail(String email) {
  List<WebUser.Project> projectDefinitions;
  try (Handle handle = dbi.open()) {
    final Map<String, Object> data = handle
        .createQuery("SELECT id, name, read_only, created_at FROM web_user WHERE lower(email) = lower(:email)")
        .bind("email", email).first();
    if (data == null) {
      return Optional.empty();
    }
    String name = (String) data.get("name");
    int id = (int) data.get("id");
    boolean readOnly = (boolean) data.get("read_only");
    Timestamp createdAt = (Timestamp) data.get("created_at");
    projectDefinitions = getUserApiKeys(handle, id);
    return Optional.of(new WebUser(id, email, name, readOnly, createdAt.toInstant(), generateIntercomHash(email), projectDefinitions));
  }
}

代码示例来源：origin: rakam-io/rakam

public <T> T get(Handle handle, @Named("user_id") UIPermissionParameterProvider.Project project, @ApiParam("name") String name) {
  return (T) handle.createQuery("SELECT value FROM ui_user_defaults WHERE user_id = :user AND project_id = :project AND name = :name")
      .bind("project", project.project)
      .bind("user", project.userId)
      .bind("name", name.toUpperCase(Locale.ENGLISH))
      .map((index, r, ctx) -> {
        return JsonHelper.read(r.getString(1), Object.class);
      }).first();
}

代码示例来源：origin: rakam-io/rakam

public Map<String, String> get(int project, String slug) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("SELECT data FROM custom_page WHERE project_id = :project AND slug = :slug")
        .bind("project", project)
        .bind("slug", slug)
        .map((i, resultSet, statementContext) -> {
          return JsonHelper.read(resultSet.getString(1), Map.class);
        }).first();
  }
}

代码示例来源：origin: rakam-io/rakam

public ABTestingReport get(String project, int id) {
  try (Handle handle = dbi.open()) {
    return handle.createQuery("SELECT id, name, variants, collection_name, connector_field, goals, options " +
        "FROM ab_testing WHERE project = :project AND id = :id")
        .bind("project", project)
        .bind("id", id).map(mapper).first();
  }
}

代码示例来源：origin: rakam-io/rakam

public Lock tryLock(String name, int tryCount) {
  Boolean first;
  try {
    first = currentHandle.createQuery("select get_lock(:name, 1)")
        .bind("name", name)
        .map(BooleanMapper.FIRST)
        .first();
  } catch (Exception e) {
    synchronized (this) {
    currentHandle.createQuery("select release_lock(:name)")
        .bind("name", name)
        .map(BooleanMapper.FIRST)
        .first();
  };