Question

使用DBI连接到MySQL数据库后，我启用了trace这样的

$dbh->trace('SQL|DBD');

然后在此之后我的SQL查询打印两次：

>count_params statement SELECT table1.ID ID, table1.LinkID LinkID, Link.ID Link_ID FROM `table1` `table1` JOIN `table2` `Link` ON `table1`.`LinkID` = `Link`.`ID` WHERE table1.ID = ?
>parse_params statement SELECT table1.ID ID, table1.LinkID LinkID, Link.ID Link_ID FROM `table1` `table1` JOIN `table2` `Link` ON `table1`.`LinkID` = `Link`.`ID` WHERE table1.ID = ?

如何只打印每个执行的SQL语句一次？

Answer 1

如何只打印每个执行的SQL语句一次？

你做不到。 Add-Type -AssemblyName System.Drawing $filename ="$env:userprofile\Desktop\px95.png" $bitmap = New-Object System.Drawing.Bitmap 95,19 $barBlendWidth = 20 $start = $bitmap.Width - $barBlendWidth $mid = $bitmap.Width - ( 0 + $barBlendWidth / 2 ) $p0 = New-Object System.Drawing.Point($start, 10 ) $p1 = New-Object System.Drawing.Point($mid, 10 ) $p2 = New-Object System.Drawing.Point($bitmap.Width, 10 ) $fromColour = [System.Drawing.Color]::FromArgb(255, 144, 238, 144) $midColour = [System.Drawing.Color]::FromArgb(255, 255, 255, 255) $toColour = [System.Drawing.Color]::FromArgb(255, 255, 255, 70) $brushBG = [System.Drawing.Brushes]::LightGreen $brush1 = New-Object System.Drawing.Drawing2D.LinearGradientBrush($p0, $p1, $fromColour, $midColour) $brush2 = New-Object System.Drawing.Drawing2D.LinearGradientBrush($p1 , $p2, $midColour, $toColour) $graphics = [System.Drawing.Graphics]::FromImage($bitmap) $graphics.FillRectangle($brushBG, 0, 0, $bitmap.Width, $bitmap.Height) $graphics.FillRectangle($brush1 , $start ,0,$barBlendWidth,$bitmap.Height) $graphics.FillRectangle($brush2 , $mid ,0,$barBlendWidth,$bitmap.Height) $bitmap.Save($filename)和count_params是DBD :: mysql用于在客户端上模拟预准备语句的内部函数。执行预准备语句时都会调用它们。

在准备语句时调用

count_params并包含以下内容：

parse_params

执行语句时会调用

parse_params并包含以下内容：

if (DBIc_DBISTATE(imp_xxh)->debug >= 2)
  PerlIO_printf(DBIc_LOGPIO(imp_xxh), ">count_params statement %s\n", statement);

两者的逻辑是相同的，所以它可以是全部或全部。

使用DBI启用SQL跟踪时，如何防止语句多次输出？

1 个答案: