Question

如何检查特定表是否表示表A在hive中是空的。我需要将其作为布尔值存储到我的java代码中的变量。我试过这个

Statement stmt = con.createStatement();

    stmt.execute("Select count(*) from "+tableName);
    int ct = stmt.getUpdateCount();
    logger.info("Hive Table count is " +ct);
    if(ct > 0)
      return false;
    else
     return true;

但这似乎不起作用。有什么建议吗？

Answer 1

试试这个：

    Statement stmt = con.createStatement();
    ResultSet rs = stmt.executeQuery("Select count(*) from "+tableName);
    int ct = rs.getInt(0);
    logger.info("Hive Table count is " +ct);
    if(ct > 0)
      return false;
    else
     return true;

Answer 2

你可以这样试试：

ResultSet resultSet;
resultSet = stmt.executeQuery("select * from "+tableName);
int count = 0;
while (resultSet.next()) {
    count++;
} 
if(count == 0) // Table is empty.

蜂巢表是空检查

2 个答案: