Question

我有一个数据源文件，我使用COPY命令在Redshift中加载。

该文件有一堆日期列，年份格式为两位数（我知道，我在这里处理恐龙）。

Redshift识别日期格式，但问题是文件的值如下：

     public List<Tuple<String, int>> getHistoricalShipList(int theme)
        {
            List<Tuple<String, int>> list = new List<Tuple<string, int>>();

            using (db)
            {
                   cmd = new SqlCommand(@"Select ShipName, ShipLength from Ships Where HistID=@theme", db);
                   cmd.Parameters.AddWithValue("@theme", theme);

                db.Open();

                SqlDataReader reader = cmd.ExecuteReader();

                if (reader.HasRows) // always returning false
                {
                    //Loop through results
                    while (reader.Read())
                    {
                        String shipName = reader[0].ToString();
                        int shipLength = Convert.ToInt32(reader[1]);
                        list.Add(Tuple.Create(shipName, shipLength));
                    }
                }
                db.Close();
            }

            return list;
        }

实际上意味着：

06/01/79

然而Redshift将其解释为：

2079-06-01

有没有办法告诉Redshift我的两位数日期格式的阈值是多少。例如，低于90的值应解释为20XX。

COPY命令中的DATEFORMAT参数没有这样的选项。

Answer 1

-- Begin transaction
BEGIN TRANS;
--  Create a temp table
CREATE TEMP TABLE my_temp (dtm_str CHAR(8));
-- Load your data into the temp table
COPY my_temp FROM s3://my_bucket … ;
-- Insert your data into the final table
INSERT INTO final_table
-- Grab the first 6 chars and concatenate to the following
SELECT CAST(LEFT(dtm_str,6)||
-- Convert the last 2 chars to and in and compare to your threshold
       CASE WHEN CAST(RIGHT(dtm_str,2) AS INT) < 85
-- Add either 1900 or 2000 to the INT, convert to CHAR
            THEN CAST(CAST(RIGHT(dtm_str,2) AS INT) + 2000 AS CHAR(4))
       ELSE CAST(CAST(RIGHT(dtm_str,2) AS INT) + 1900 AS CHAR(4)) END
-- Convert the final CHAR to a DATE
       AS DATE) new_dtm
FROM my_temp;
COMMIT;

Redshift COPY语句加载日期格式，两位数年份（mm / dd / yy）

1 个答案: