如何使用powershell将内容从一个CSV复制到另一个CSV

Question

我有两个csv文件：每个得到3列，我想比较第一列，如果匹配，它将复制其他列中的内容例如：

1 csv:

column1   column2    column3
aaa       bla        baba
ccc       bla        babab3
abc       bla        bababa3

2 csv:

column1   column4     column5
abc       dla2        blabla2
ddd       dla         blabla
ccc       dla1        blabla1
aaa       dla1        blabla1

更新csv:

column1   column2   column3   column4   column5 
aaa       bla        baba     dla1      blabla1
ccc       bla        babab3   dla1      blabla1
abc       bla        bababa3  dla2      blabla2

谢谢，

Answer 1

# Import both CSV files.
$rowsA = Import-Csv 1.csv
$rowsB = Import-Csv 2.csv
# The name of the shared column to join by.
$sharedCol = 'Column1'
# Get the column names of 2.csv, excluding the shared one.
$colsB = $rowsB[0].psobject.Properties.Name -ne $sharedCol
# Create a map (hashtable) that maps the shared column
# values to the column values of the matching 2.csv rows.
$map = @{}
$rowsB.ForEach({ $map[$_.$sharedCol] = $_.psobject.Properties[$colsB] })
# Construct empty helper properties for those $sharedCol values in 1.csv
# that have no counterpart in 2.csv
$emptyPropsB = 
([pscustomobject] @{} | Select-Object -Property $colsB).psobject.Properties
$rowsA | ForEach-Object {
$rowA = $_
# Find the matching 2.csv row's column values. If not found, use empty ones.
$colValuesB = $map[$rowA.$sharedCol]
if (-not $colValuesB) { $colValuesB = $emptyPropsB }
# Append the column values from the 2.csv row to the 1.csv row at hand.
$colValuesB.ForEach({ $rowA.psobject.Properties.Add($_) })
$rowA # Output the merged row.
} # | Export-Csv -NoTypeInformation -Encoding utf8 updated.csv

^{输出到显示器；从最后一行中删除#以导出到CSV文件}

注意：如果您想跳过没有匹配的2.csv行的1.csv行，请将
if (-not $colValuesB) { $colValuesB = $emptyPropsB }替换为
if (-not $colValuesB) { return }
此外，您不需要$emptyPropsB = ...语句。