WOLFRAM

Wolfram言語 ＆ システムドキュメントセンター

JoinAcross[{a1,a2,…},{b1,b2,…},keyspec]

keyspec で指定される値が一致する，連想 aiと bjのペアを結合することによって得られる連想のリストを与える．

JoinAcross[tab1,tab2,keyspec]

keyspec に従って2つの表形式オブジェクトを結合する．

JoinAcross[prefix1obj1,prefix2obj2,keyspec]

ExtendedKey[prefixi,ckeyij]を使って objiのキーに prefixiを前置する．

JoinAcross[alist,blist,keyspec,"joinspec"]

joinspec を使って，欠落している要素を含む連想がいつ生成されるようにするかを決定する．

詳細とオプション
Details and Options Details and Options
例題  
例  
スコープ  
オプション  
KeyCollisionFunction  
特性と関係  
考えられる問題  
関連項目
関連するガイド
関連リンク
履歴
引用書式

JoinAcross

JoinAcross[{a1,a2,…},{b1,b2,…},keyspec]

keyspec で指定される値が一致する，連想 aiと bjのペアを結合することによって得られる連想のリストを与える．

JoinAcross[tab1,tab2,keyspec]

keyspec に従って2つの表形式オブジェクトを結合する．

JoinAcross[prefix1obj1,prefix2obj2,keyspec]

ExtendedKey[prefixi,ckeyij]を使って objiのキーに prefixiを前置する．

JoinAcross[alist,blist,keyspec,"joinspec"]

joinspec を使って，欠落している要素を含む連想がいつ生成されるようにするかを決定する．

詳細とオプション

  • JoinAcross[{a1,a2,…},{b1,b2,…},keyspec]は，事実上SQL JOINと同じものを実装し，keyspec で指定された列間で，行 ai と bj を持つ2つの表を結合する．
  • JoinAcross[{a1,a2,…},{b1,b2,…},keyspec]の keyspec は，以下のいずれかでよい．
  • keykey に関連付けられた値が等しい aiと bjを結合する
    {key1,key2,…}各 keyiに関連付けられた値はすべて、マッチする各ペアで等しくなければならない
    keyakeybaiの keyaに関連付けられた値は bjの keybに関連付けられた値と等しくなければならない
    {keya1keyb1,keya2keyb2,…}ai の keyaiに関連付けられた値と bjの keybjに関連付けられた値をマッチする
    funcfunc[ai,bj]がTrueの時は常に，aiと bjのペアとを結合する
  • JoinAcross[{a1,a2,…},{b1,b2,…},keyspec]の keyspec は，事実上，以下の関数で置き換えられる．
  • key#1[key]===#2[key]&
    {key1,key2,…}#1[key1]===#2[key1]&&#1[key2]===#2[key2]&&…&
    keyakeyb#1[keya]===#2[key2]&
    {keya1keyb1,keya2keyb2,…}#1[keya1]===#2[keyb1]&&#1[keya2]===#2[keyb2]&&…&
  • JoinAcrossのキー指定は，それが文字列でなければKeyで囲まなければならない．
  • JoinAcrossは事実上，フィルタを掛けられたFlatten[Outer[Join,alist,blist]]を生成する．
  • デフォルトでJoinAcrossは，SQL的には，「内部結合」する．
  • 次の形式の"joinspec"が，連想のペア aiと bjに異なる動作を指定する．
  • "Inner"値がマッチする aiと bjのみを保つ（デフォルト）
    "Left"マッチする bjのない aiを許す
    "Right"マッチする ajのない biを許す
    "Outer"マッチしない aiと bjの両方を許す
  • 対応する値がない場合には，代りにMissing["Unmatched"]が使われる．
  • JoinAcross[{a1,…},{b1,…},{},"joinspec"]と JoinAcross[{a1,…},{b1,…},True&,"joinspec"]は，事実上，Outer[Join,{a1,…},{b1,…}]都等しい． すべての aiとすべての bjがマッチするので，"joinspec"は無視される．
  • オプションKeyCollisionFunctionを使って，結合するようには指定されていないにもかかわらず同じキーを持つ要素 aiおよび bjをどのように扱うかを指定することができる．
  • KeyCollisionFunctionで使用可能な設定
  • None両方の要素を除去する
    Left左要素だけを含める（デフォルト）
    Right右要素だけを含める
    funcfunc を適用して新たなキーペアを生成する

例題

すべて開く すべて閉じる

例  (10)

指定されたキーに対して同じ値を持つ2つの連想を結合する：

Wolfram Language code: JoinAcross[{<|"Author" -> "Mark Twain", "YearOfBirth" -> 1835|>, <|"Author" -> "Jules Verne", "YearOfBirth" -> 1828|>}, {<|"Author" -> "Mark Twain", "Title" -> "Tom Sawyer"|>, <|"Author" -> "Mark Twain", "Title" -> "Huckleberry Finn"|>}, "Author"]

Tabularオブジェクトを使って同じことを行う：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author"]

複数のキーを使って結合する：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["AuthorFirst" -> Association["ElementType" -> "String"], "AuthorLast" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 4, 9}, "MarkJules"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 5, 10}, "TwainVerne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["AuthorFirst" -> Association["ElementType" -> "String"], "AuthorLast" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 4}, "Mark"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 5}, "Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10}, "Tom Sawyer"}, {}, None}, "ElementType" -> "String"]]}}]]]], {"AuthorFirst", "AuthorLast"}]

右側と左側を異なるキーで結合する：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 36}, "Tom SawyerFrom the Earth to the Moon"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author"]

関数を使って遺作を求める：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfDeath" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10}, "Mark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{1910}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"], "Publication" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20, 30}, "Mark TwainMark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10, 26, 49}, "Tom SawyerHuckleberry FinnThe Mysterious Stranger"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1876, 1884, 1916}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], #1["Author"] === #2["Author"] && #1["YearOfDeath"] < #2["Publication"]&]

規則を使ってキーの衝突を避ける：

Wolfram Language code: JoinAcross["Author" -> Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], "Book" -> Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Name" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author"]

"Inner"結合（デフォルト）では，マッチする連想のみが繋がれる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20, 34}, "Mark TwainMark TwainEmilio Salgari"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10, 26, 34}, "Tom SawyerHuckleberry FinnSandokan"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author", "Inner"]

"Left"結合では，左側のリストからのマッチしない項目も含まれる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20, 34}, "Mark TwainMark TwainEmilio Salgari"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10, 26, 34}, "Tom SawyerHuckleberry FinnSandokan"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author", "Left"]

"Right"結合では，右側のリストからのマッチしない項目も含まれる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20, 34}, "Mark TwainMark TwainEmilio Salgari"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10, 26, 34}, "Tom SawyerHuckleberry FinnSandokan"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author", "Right"]

"Outer"結合では，マッチしないすべての項目が含まれる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20, 34}, "Mark TwainMark TwainEmilio Salgari"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association["Data" -> {{3, {0, 10, 26, 34}, "Tom SawyerHuckleberry FinnSandokan"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author", "Outer"]

スコープ  (1)

JoinAcrossはSQLベースのTabularに使うことができる：

Wolfram Language code: schema = RelationalDatabase[FindFile["ExampleData/ecommerce-database.sqlite"]]
Wolfram Language code: offices = Tabular[schema -> "offices"]
Wolfram Language code: employees = Tabular[schema -> "employees"]
Wolfram Language code: joined = JoinAcross["employees" -> employees, "offices" -> offices, "officeCode"]
Wolfram Language code: ToMemory[joined]

オプション  (3)

KeyCollisionFunction  (3)

キー b のマッチングが結合に使われないときは，デフォルトで，このキーに対して左側の値が使われる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Name" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author"]

KeyCollisionFunctionを使って，衝突するどちらのキーの値を返すかを指定する：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Name" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author", KeyCollisionFunction -> Right]

衝突するキーの代りに新しいキーを生成する：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Name" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author", KeyCollisionFunction -> Function[x, {left[x], right[x]}]]

衝突するキーを除く：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Name" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Name" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Name" -> "Author", KeyCollisionFunction -> None]

特性と関係  (2)

場合によって，JoinAcrossをColumnwiseCombineと書き換えることができる：

Wolfram Language code: JoinAcross[Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]], "Author"]
Wolfram Language code: ColumnwiseCombine[{Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "YearOfBirth" -> Association["ElementType" -> "Integer64"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 21}, "Mark TwainJules Verne"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{1835, 1828}, {}, None}, "ElementType" -> "Integer64"]]}}]]]], Tabular[Association["RawSchema" -> Association["ColumnProperties" -> Association["Author" -> Association["ElementType" -> "String"], "Title" -> Association["ElementType" -> "String"]], "KeyColumns" -> None, "Backend" -> "WolframKernel"], "Options" -> {}, "BackendData" -> Association["ColumnData" -> DataStructure["ColumnTable", {{TabularColumn[Association["Data" -> {{3, {0, 10, 20}, "Mark TwainMark Twain"}, {}, None}, "ElementType" -> "String"]], TabularColumn[Association[ "Data" -> {{3, {0, 10, 26}, "Tom SawyerHuckleberry Finn"}, {}, None}, "ElementType" -> "String"]]}}]]]]} -> "Author"]

JoinAcrossはCombinedEntityClassに等しい：

Wolfram Language code: EntityValue[CombinedEntityClass["Isotope", EntityClass["Element", "Period1"], "Element" -> "Entity"], {EntityProperty["Isotope", "Element"], EntityProperty["Isotope", "Name"], EntityProperty["Isotope", "AtomicMass"], EntityProperty["Element", "Entity"], EntityProperty["Element", "AtomicMass"]}, "PropertyAssociation"]//Tabular
Wolfram Language code: JoinAcross[EntityValue["Isotope", {EntityProperty["Isotope", "Element"], EntityProperty["Isotope", "Name"], EntityProperty["Isotope", "AtomicMass"]}, "PropertyAssociation"], EntityValue[EntityClass["Element", "Period1"], {EntityProperty["Element", "Entity"], EntityProperty["Element", "AtomicMass"]}, "PropertyAssociation"], EntityProperty["Isotope", "Element"] -> EntityProperty["Element", "Entity"]]//Tabular

考えられる問題  (1)

キー a とキー b は結合のために使われていても衝突する：

Wolfram Language code: JoinAcross[{<|a -> 1, b -> 2|>}, {<|a -> 2, b -> 1|>}, {Key[a] -> Key[b], Key[b] -> Key[a]}, "Left", KeyCollisionFunction -> Function[x, {left[x], right[x]}]]

キーが衝突すると，デフォルトで左側のキーからの値が取られる：

Wolfram Language code: JoinAcross[{<|a -> 1, b -> 2|>}, {<|a -> 2, b -> 1|>}, {Key[a] -> Key[b], Key[b] -> Key[a]}, "Left"]

衝突したキーのどちらの値を取るか指定する：

Wolfram Language code: JoinAcross[{<|a -> 1, b -> 2|>}, {<|a -> 2, b -> 1|>}, {Key[a] -> Key[b], Key[b] -> Key[a]}, "Left", KeyCollisionFunction -> Left]

衝突したキーの右側の値を明確に取る：

Wolfram Language code: JoinAcross[{<|a -> 1, b -> 2|>}, {<|a -> 2, b -> 1|>}, {Key[a] -> Key[b], Key[b] -> Key[a]}, "Left", KeyCollisionFunction -> Right]
Wolfram Research (2014), JoinAcross, Wolfram言語関数， https://reference.wolfram.com/language/ref/JoinAcross.html （2025年に更新）.

テキスト

Wolfram Research (2014), JoinAcross, Wolfram言語関数， https://reference.wolfram.com/language/ref/JoinAcross.html （2025年に更新）.

CMS

Wolfram Language. 2014. "JoinAcross." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/JoinAcross.html.

APA

Wolfram Language. (2014). JoinAcross. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/JoinAcross.html

BibTeX

@misc{reference.wolfram_2026_joinacross, author="Wolfram Research", title="{JoinAcross}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/JoinAcross.html}", note=[Accessed: 29-October-2026]}

BibLaTeX

@online{reference.wolfram_2026_joinacross, organization={Wolfram Research}, title={JoinAcross}, year={2025}, url={https://reference.wolfram.com/language/ref/JoinAcross.html}, note=[Accessed: 29-October-2026]}