Question

我试图将多个csv文件加载到mysql中以创建这些文件的单个表。我在mysql中加载了一个名为symbol的表，该表的一列名为ticker，所有行值都表示诸如A，B，C等的符号。我想遍历这些行以创建路径为/path/A.csv这样我就可以从所有这些文件中读取数据以创建新表all_tickers。

之前，我在SQL Server中使用以下代码进行了此操作：

CREATE TABLE dbo.all_tickers
(
     ticker_symbol varchar(32) NOT NULL,
     [Date] datetime2(7) NOT NULL,
     [Open] float NULL,
     High float NULL,
     Low float NULL,
     [close] float NULL,
     Volume float NULL,

     PRIMARY KEY (ticker_symbol, [Date])
);
GO

DECLARE @Path nvarchar(255) = 'D:\ASX';
DECLARE @SQL nvarchar(MAX);

CREATE TABLE #ticker_staging
(
     [Date] datetime2(7) NOT NULL,
     [Open] float NULL,
     High float NULL,
     Low float NULL,
     [close] float NULL,
     Volume float NULL
);

SET @SQL = (SELECT N'
TRUNCATE TABLE #ticker_staging;
BULK INSERT #ticker_staging
    FROM ''' + @Path + N'\' + ticker + N'.csv''
    WITH
    (
    FIRSTROW = 2,
    FIELDTERMINATOR = '','',  --CSV field delimiter
    ROWTERMINATOR = ''\n'',   --Use to shift the control to next row
    TABLOCK
    );
INSERT INTO dbo.all_tickers WITH (TABLOCKX)(
  ticker_symbol,
  [Date],
  [Open],
  High,
  Low,
  [close],
  Volume
) 
SELECT
  ''' + ticker + N''',
  [Date],
  [Open],
  High,
  Low,
  [close],
  Volume
FROM #ticker_staging;'
FROM dbo.symbols
FOR XML PATH(''), TYPE).value('.',N'nvarchar(MAX)');
EXECUTE sp_executesql @SQL;
GO

要在MySQL中复制结果，我将上面的代码更改为如下：

CREATE TABLE dbo.all_tickers
(
     ticker_symbol varchar(32) NOT NULL,
     Date datetime NOT NULL,
     Open float NULL,
     High float NULL,
     Low float NULL,
     close float NULL,
     Volume float NULL,

     PRIMARY KEY (ticker_symbol, Date)
);

set @Path = 'D:\ASX';
set @SQL = nvarchar(MAX);

CREATE TABLE #ticker_staging 
( 
    Date1 datetime NOT NULL,
    Open float NULL,
    High float NULL,
    Low float NULL,
    close float NULL,
    Volume float NULL
);

SET @SQL = (SELECT N'
TRUNCATE TABLE #ticker_staging;
LOAD DATA INFILE #ticker_staging
    FROM ''' + @Path + N'\' + ticker + N'.csv''
    WITH
    (
    FIRSTROW = 2,
    FIELDTERMINATOR = '','',  #CSV field delimiter
    ROWTERMINATOR = ''\n'',   #Use to shift the control to next row
    TABLOCK
    );
INSERT INTO dbo.all_tickers WITH (TABLOCKX)(
  ticker_symbol,
  [Date],
  [Open],
  High,
  Low,
  [close],
  Volume
) 
SELECT
  ''' + ticker + N''',
  [Date],
  [Open],
  High,
  Low,
  [close],
  Volume
FROM #ticker_staging;'
FROM dbo.SCRIP
FOR XML PATH(''), TYPE).value('.',N'nvarchar(MAX)');
EXECUTE sp_executesql @SQL;

我在处理SQL Server中用于将其转换成MySQL的WITH子句时遇到问题。

由于我是MySQL的新手，所以我认为这是主要问题。如果代码中还有其他问题，请提出建议。

将多个CSV数据加载到MySQL中

0 个答案: