編集¶

スナッピング許容値¶

スナッピングの許容値とは接続や新規頂点入力や既存頂点移動を行いたいときに QGIS が最も近い頂点やセグメントを 検索 する場合の許容距離です. もしあなたの入力場所のスナッピング許容値内に頂点やセグメントが無い場合, QGIS は既存の頂点やセグメントにスナップさせる代わりにマウスボタンを離した場所に頂点を作成します. スナッピング許容値の設定はすべての許容値を利用するツールに影響をあたえます.

1. A general, project-wide snapping tolerance can be defined by choosing Settings ‣ Options. On Mac, go to QIS ‣ Preferences.... On Linux: Edit ‣ Options. In the Digitizing tab, you can select between ‘to vertex’, ‘to segment’ or ‘to vertex and segment’ as default snap mode. You can also define a default snapping tolerance and a search radius for vertex edits. The tolerance can be set either in map units or in pixels. The advantage of choosing pixels is that the snapping tolerance doesn’t have to be changed after zoom operations. In our small digitizing project (working with the Alaska dataset), we define the snapping units in feet. Your results may vary, but something on the order of 300 ft at a scale of 1:10000 should be a reasonable setting.

2. レイヤ別スナッピング許容値はメニュー Settings ‣ (または File ‣) Snapping options... で指定できます.ここでレイヤ単位でスナッピングモードを有効にして許容値を調整できます (figure_edit_1 参照).

注 このレイヤ別スナッピング定義はデジタイジングタブで設定できるグローバルスナッピングオプションを上書きします.ですからあなたがあるレイヤを編集する時に他のレイヤの頂点にスナップしたい場合レイヤに対する スナップする を有効にしてグローバルスナップ許容値をそれより小さい値にする必要があります.さらにグローバルスナッピング許容値に関係なくスナッピングオプションダイアログでチェックしていないレイヤに対してはスナップできません.ですからスナップしたいレイヤについてはチェックボックスのマークに注意して下さい.

Figure Edit 1:

レイヤ単位での編集スナップオプション

検索半径¶

検索半径とはあなたが地図をクリックした時に QGIS が最も近い頂点を 検索 するために使う距離です. 検索半径内に無い場合, QGIS は編集用頂点を見つけられず編集用頂点を選択できず警告がポップアップされます. スナップ許容値と検索半径は地図上の単位かピクセルで設定できます.そこで必要に応じて正しい値を設定することができます. もし大きな値を許容値に設定すると, QGIS は誤った頂点にスナップするでしょう, とりわけ多くの頂点を使うとそうなるでしょう. 検索半径を小さい値にすると何も見つからないはずでしょう.

レイヤにおける頂点編集のための検索半径の単位は Settings ‣ Options にある Digitizing タブで定義できます.同じ場所でプロジェクト全体のスナッピング許容値を定義することもできます.

マウスホイールを使ったズームとパンニング¶

デジタイズを行っている間メインウィンドウでマウスホィールを使ってパンを行うことができます,そしてマウスホィールを転がすことで地図の拡大,縮小を行うことができます. 拡大を行う場合マウスカーソルを地図エリアで向こう側に（あなたと逆方向に）動かしてください,マウスカーソルを手前に（あなたのほうに）動かすと縮小します. マウスカーソルの位置はズームしたい位置の中心にあります. マウスホィールのズームの動作は Options メニューの Settings ‣ にある Map tools タブでカスタマイズできます.

矢印キーを使ったパン¶

デジタイズ作業時に矢印キーを使ってパンを行うことができます. マウスカーソルを地図エリアにおきクリックした後右矢印キーを押すと東にパンします,左矢印キーを押すと西にパンします,上矢印キーを押すと北にパンします.下矢印キーを押すと南にパンします.

スペースバーを地図のパン作業の中断に利用できます.キーボードの PgUp と PgDown キーを使うとデジタイジング作業を中断することなく地図の拡大、縮小を行うことができます.

トポロジ編集を有効にする¶

The option Enable topological editing is for editing and maintaining common boundaries in polygon mosaics. QGIS ‘detects’ a shared boundary in a polygon mosaic, so you only have to move the vertex once, and QGIS will take care of updating the other boundary.

新規ポリゴンの重なりの禁止¶

２つ目のトポロジカルオプションは 交差禁止. で, called 新規ポリゴンの重なり禁止 と呼ばれポリゴンモザイクでの重なりを禁止するものです. これにより隣接ポリゴンの迅速なデジタイズができます. もしあるポリゴンが存在しているところでこのオプションを使って隣接ポリゴンを重なる形でデジタイズすると QGIS は２つめのポリゴンを共通境界線で自動的にカットします.これによってユーザが共通境界線の頂点をデジタイズしなくていい利点ができます.

交差に対するスナッピングを有効にする¶

Another option is to use Enable snapping on intersection. It allows you to snap on an intersection of background layers, even if there’s no vertex on the intersection.

フィーチャの追加¶

You can use the ^{Add Feature}, ^{Add Feature} or ^{Add Feature} icons on the toolbar to put the QGIS cursor into digitizing mode.

それぞれの地物に対し、まずジオメトリをデジタイズし、属性を入力します。ジオメトリをデジタイズするには、マップエリアで左クリックし新しい地物の最初の頂点を作成します。

ラインとポリゴンで点を追加する場合は入力したい位置にマウス左ボタンでクリックを続けてください.点の追加を終了したい場合は地図上のどこかをマウス右ボタンでクリックして地物のジオメトリ入力終了を確認して下さい.

The attribute window will appear, allowing you to enter the information for the new feature. Figure_edit_2 shows setting attributes for a fictitious new river in Alaska. In the Digitizing menu under the Settings ‣ Options menu, you can also activate Suppress attributes pop-up windows after each created feature and Reuse last entered attribute values.

Figure Edit 2:

新しいベクタ地物のデジタイズの後で属性値を入力するダイアログ

With the ^{Move Feature(s)} icon on the toolbar, you can move existing features.

現在の編集¶

This new feature allows the digitization of multiple layers. Choose Save for Selected Layers to save all changes you made in multiple layers. You also have the opportunity to Rollback for Selected Layers, so that the digitization may be withdrawn for all selected layers. If you want to stop editing the selected layers, Cancel for Selected Layer(s) is an easy way.

同じ機能がプロジェクトの全レイヤの編集で可能です.

ノードツール¶

For shapefile-based layers as well as SpatialLite, PostgreSQL/PostGIS, MSSQL Spatial, and Oracle Spatial tables, the ^{Node Tool} provides manipulation capabilities of feature vertices similar to CAD programs. It is possible to simply select multiple vertices at once and to move, add or delete them altogether. The node tool also works with ‘on the fly’ projection turned on, and it supports the topological editing feature. This tool is, unlike other tools in QGIS, persistent, so when some operation is done, selection stays active for this feature and tool. If the node tool is unable to find any features, a warning will be displayed.

It is important to set the property Settings ‣ Options ‣ Digitizing ‣ Search Radius: to a number greater than zero (i.e., 10). Otherwise, QGIS will not be able to tell which vertex is being edited.

基本操作¶

Start by activating the ^{Node Tool} and selecting a feature by clicking on it. Red boxes will appear at each vertex of this feature.

• Selecting vertices: You can select vertices by clicking on them one at a time, by clicking on an edge to select the vertices at both ends, or by clicking and dragging a rectangle around some vertices. When a vertex is selected, its color changes to blue. To add more vertices to the current selection, hold down the Ctrl key while clicking. Hold down Ctrl or Shift when clicking to toggle the selection state of vertices (vertices that are currently unselected will be selected as usual, but also vertices that are already selected will become unselected).
• Adding vertices: To add a vertex, simply double click near an edge and a new vertex will appear on the edge near to the cursor. Note that the vertex will appear on the edge, not at the cursor position; therefore, it should be moved if necessary.

• 頂点の削除: 削除する頂点を選択した後 Delete キーをクリックして下さい. 注意 ^{Node Tool} は地物全部を削除することはできません; QGIS は作業している地物の大部で最低必要な数の頂点は確保します. 地物そのものを削除する場合は ^{Delete Selected} ツールを使って下さい.

• 頂点の移動: 移動したい頂点を選択して下さい. 選択した頂点またはエッジをクリックして移動したい方向にドラッグして下さい. すべての選択した頂点は一緒に移動します. もしスナッピングが有効ならばすべての選択物はもっとも近い頂点かラインにジャンプすることもできます.

Each change made with the node tool is stored as a separate entry in the Undo dialog. Remember that all operations support topological editing when this is turned on. On-the-fly projection is also supported, and the node tool provides tooltips to identify a vertex by hovering the pointer over it.

地物の切り取り、コピーと貼り付け¶

Selected features can be cut, copied and pasted between layers in the same QGIS project, as long as destination layers are set to ^{Toggle editing} beforehand.

地物は、テキストなどの外部アプリケーションに貼り付けることができます。つまり、地物は、ジオメトリデータをOGC well-known Text（WKT）形式としてCSV形式で表現されます。

However, in this version of QGIS, text features from outside QGIS cannot be pasted to a layer within QGIS. When would the copy and paste function come in handy? Well, it turns out that you can edit more than one layer at a time and copy/paste features between layers. Why would we want to do this? Say we need to do some work on a new layer but only need one or two lakes, not the 5,000 on our big_lakes layer. We can create a new layer and use copy/paste to plop the needed lakes into it.

例として新しいレイヤにいくつかの湖沼をコピーします:

1. コピーしたいレイヤをロードします (ソースレイヤ)

2. コピー先にしたいレイヤをロードまたは作成します(ターゲットレイヤ)

3. ターゲットレイヤの編集を開始します

4. 凡例をクリックしてソースレイヤをアクティブにします

5. Use the ^{Select Single Feature} tool to select the feature(s) on the source layer
6. Click on the ^{Copy Features} tool

7. 判例をクリックしてコピー先レイヤをアクティブにして下さい

8. Click on the ^{Paste Features} tool

9. 編集モードを終了して変更内容を保存して下さい

ソースとターゲットレイヤのスキーマ(フィールド名と型が異なる場合)が異なる場合どうなるでしょうか? QGIS はマッチできる項目以外を無視します.もしあなたがターゲットレイヤにコピーする属性の内容にこだわらない場合はフィールドとデータタイプの設計は重要ではありません.すべてを - 地物とその属性 - 正しくコピーしたい場合はスキーマを一致させなければなりません.

選択地物の削除¶

ポリゴン全体を削除したい場合最初に通常の ^{Select Single Feature} ツールでポリゴンを選択して下さい.削除のために複数の地物を選択することも可能です.選択を行うと ^{Delete Selected} ツールを使って地物を削除することができます.

The ^{Cut Features} tool on the digitizing toolbar can also be used to delete features. This effectively deletes the feature but also places it on a “spatial clipboard”. So, we cut the feature to delete. We could then use the ^{Paste Features} tool to put it back, giving us a one-level undo capability. Cut, copy, and paste work on the currently selected features, meaning we can operate on more than one at a time.

編集レイヤの保存¶

When a layer is in editing mode, any changes remain in the memory of QGIS. Therefore, they are not committed/saved immediately to the data source or disk. If you want to save edits to the current layer but want to continue editing without leaving the editing mode, you can click the ^{Save Layer Edits} button. When you turn editing mode off with ^{Toggle editing} (or quit QGIS for that matter), you are also asked if you want to save your changes or discard them.

もし変更が保存されなかった場合 (たとえば., ディスクが満杯だとか属性の値が指定の範囲の外であるとか), QGIS はメモリーの状態を保存します. これによって編集内容を調整して再度保存を試すことができます.

アンドゥとリドゥ¶

^取り消し と ^再実行 ツールを使うとベクタ編集操作の取り消しや再実行を行うことができます.取り消し/再実行操作の全履歴を表示できる結合表示可能なウィジェットもあります ( Figure_edit_3 参照). このウィジェットはデフォルトでは表示されていません; このウィジェットはツールバー上でマウス右ボタンをクリックして取り消し/再実行チェックボックスをアクティブにすることで表示できます. ウィジェットが表示されていなくても取り消し/再実行機能は有効です.

Figure Edit 3:

デジタイジングステップのリドゥとアンドゥ

When Undo is hit, the state of all features and attributes are reverted to the state before the reverted operation happened. Changes other than normal vector editing operations (for example, changes done by a plugin), may or may not be reverted, depending on how the changes were performed.

undo/redo ヒストリウィジェットを利用する場合単純に操作のヒストリリストをクリックして下さい. すべての操作は選択操作のあとであった状態に戻されます.

フィーチャ（群）の回転¶

Use ^{Rotate Feature(s)} to rotate one or multiple selected features in the map canvas. You first need to select the features and then press the ^{Rotate Feature(s)} icon. The centroid of the feature(s) appears and will be the rotation anchor point. If you selected multiple features, the rotation anchor point will be the common center of the features. Press and drag the left mouse button in the desired direction to rotate the selected features.

It’s also possible to create a user-defined rotation anchor point around which the selected feature will rotate. Select the features to rotate and activate the ^{Rotate Feature(s)} tool. Press and hold the Ctrl button and move the mouse pointer (without pressing the mouse button) to the place where you want the rotation anchor to be moved. Release the Ctrl button when the desired rotation anchor point is reached. Now, press and drag the left mouse button in the desired direction to rotate the selected feature(s).

地物の簡素化¶

The ^{Simplify Feature} tool allows you to reduce the number of vertices of a feature, as long as the geometry doesn’t change. First, select a feature. It will be highlighted by a red rubber band and a slider will appear. Moving the slider, the red rubber band will change its shape to show how the feature is being simplified. Click [OK] to store the new, simplified geometry. If a feature cannot be simplified (e.g. multi-polygons), a message will appear.

リングの追加¶

You can create ring polygons using the ^{Add Ring} icon in the toolbar. This means that inside an existing area, it is possible to digitize further polygons that will occur as a ‘hole’, so only the area between the boundaries of the outer and inner polygons remains as a ring polygon.

パートの追加¶

You can ^{add part} polygons to a selected multipolygon. The new part polygon must be digitized outside the selected multi-polygon.

リングの塗りつぶし¶

You can use the ^{Fill Ring} function to add a ring to a polygon and add a new feature to the layer at the same time. Thus you need not first use the ^{Add Ring} icon and then the ^{Add feature} function anymore.

リングの削除¶

The ^{Delete Ring} tool allows you to delete ring polygons inside an existing area. This tool only works with polygon layers. It doesn’t change anything when it is used on the outer ring of the polygon. This tool can be used on polygon and multi-polygon features. Before you select the vertices of a ring, adjust the vertex edit tolerance.

パートの削除¶

The ^{Delete Part} tool allows you to delete parts from multifeatures (e.g., to delete polygons from a multi-polygon feature). It won’t delete the last part of the feature; this last part will stay untouched. This tool works with all multi-part geometries: point, line and polygon. Before you select the vertices of a part, adjust the vertex edit tolerance.

地物の変形¶

You can reshape line and polygon features using the ^{Reshape Features} icon on the toolbar. It replaces the line or polygon part from the first to the last intersection with the original line. With polygons, this can sometimes lead to unintended results. It is mainly useful to replace smaller parts of a polygon, not for major overhauls, and the reshape line is not allowed to cross several polygon rings, as this would generate an invalid polygon.

たとえばポリゴンの境界線をこのツールで編集できます. 最初にポリゴンの内側をクリックした後に新しく頂点を追加したい位置に点を入力してください. それから境界線をまたいでポリゴンの外側に頂点を追加してください. このツールは境界線と新しい線の交点に自動的にノードを追加します. これはポリゴンの一部を削除する場合にも利用できます, ポリゴンの外側から新しいラインを開始して内側に新しい頂点を追加します,そしてポリゴンの外側に最終点を右ボタンクリックで作成してください.

オフセットカーブ¶

The ^{Offset Curve} tool creates parallel shifts of line layers. The tool can be applied to the edited layer (the geometries are modified) or also to background layers (in which case it creates copies of the lines / rings and adds them to the the edited layer). It is thus ideally suited for the creation of distance line layers. The displacement is shown at the bottom left of the taskbar. To create a shift of a line layer, you must first go into editing mode and then select the feature. You can make the ^{Offset Curve} tool active and drag the cross to the desired distance. Your changes may then be saved with the ^{Save Layer Edits} tool.

地物の分割¶

ツールバー上の ^{Split Features} アイコンを使って地物を分割できます. 分割したい地物を交差する線を描画すれば分割できます.

部分の分割¶

In QGIS 2.0 it is now possible to split the parts of a multi part feature so that the number of parts is increased. Just draw a line across the part you want to split using the ^{Split Parts} icon.

選択フィーチャのマージ¶

The ^{Merge Selected Features} tool allows you to merge features that have common boundaries and the same attributes.

選択地物の属性マージ¶

The ^{Merge Attributes of Selected Features} tool allows you to merge attributes of features with common boundaries and attributes without merging their boundaries. First, select several features at once. Then press the ^{Merge Attributes of Selected Features} button. Now QGIS asks you which attributes are to be applied to all selected objects. As a result, all selected objects have the same attribute entries.

ポイントシンボルの回転¶

^{Rotate Point Symbols} allows you to change the rotation of point symbols in the map canvas. You must first define a rotation column from the attribute table of the point layer in the Advanced menu of the Style menu of the Layer Properties. Also, you will need to go into the ‘SVG marker’ and choose Data defined properties .... Activate Angle and choose ‘rotation’ as field. Without these settings, the tool is inactive.

Figure Edit 4:

ポイントシンボルの回転

To change the rotation, select a point feature in the map canvas and rotate it, holding the left mouse button pressed. A red arrow with the rotation value will be visualized (see Figure_edit_4). When you release the left mouse button again, the value will be updated in the attribute table.

新規Shapefileレイヤの作成¶

To create a new shape layer for editing, choose New ‣ New Shapefile Layer... from the Layer menu. The New Vector Layer dialog will be displayed as shown in Figure_edit_5. Choose the type of layer (point, line or polygon) and the CRS (coordinate reference system).

注 QGIS はまだ 2.5D 地物の作成をサポートしていません (例. X,Y,Z座標を持つ地物).

Figure Edit 5:

新規Shapefile作成ダイアログ

To complete the creation of the new shapefile layer, add the desired attributes by clicking on the [Add to attributes list] button and specifying a name and type for the attribute. A first ‘id’ column is added as default but can be removed, if not wanted. Only Type: real , Type: integer , Type: string and Type:date attributes are supported. Additionally and according to the attribute type, you can also define the width and precision of the new attribute column. Once you are happy with the attributes, click [OK] and provide a name for the shapefile. QGIS will automatically add a .shp extension to the name you specify. Once the layer has been created, it will be added to the map, and you can edit it in the same way as described in section 既存レイヤのデジタイズ above.

新規Spatialiteレイヤの作成¶

編集用に新しい SpatiaLite レイヤを作成するために Layer　メニューで New ‣ New SpatiaLite Layer... を選択して下さい. New SpatiaLite Layer ダイアログが Figure_edit_6 のように表示されます.

Figure Edit 6:

新規Spatialiteレイヤ作成ダイアログ

The first step is to select an existing SpatiaLite database or to create a new SpatiaLite database. This can be done with the browse button to the right of the database field. Then, add a name for the new layer, define the layer type, and specify the coordinate reference system with [Specify CRS]. If desired, you can select Create an autoincrementing primary key.

To define an attribute table for the new SpatiaLite layer, add the names of the attribute columns you want to create with the corresponding column type, and click on the [Add to attribute list] button. Once you are happy with the attributes, click [OK]. QGIS will automatically add the new layer to the legend, and you can edit it in the same way as described in section 既存レイヤのデジタイズ above.

SpatiaLiteレイヤ の高度な管理はDB マネージャを使うと実行できます DB マネージャプラグイン 参照.

新しいGPXレイヤの作成¶

新しい GPXファイルを作成するためには GPS プラグインを最初にロードする必要があります. Plugins ‣ Plugin Manager... で Plugin Manager ダイアログを開いてください. GPS Tools チェックボックスをアクティブにして下さい.

このプラグインがロードされると Layer メニューで New ‣ Create new GPX Layer... を選択できます. Save new GPX file as ダイアログで新しい GPX レイヤを保存する場所を選べます.

属性テーブルにおける地物の選択¶

Each selected row in the attribute table displays the attributes of a selected feature in the layer. If the set of features selected in the main window is changed, the selection is also updated in the attribute table. Likewise, if the set of rows selected in the attribute table is changed, the set of features selected in the main window will be updated.

Rows can be selected by clicking on the row number on the left side of the row. Multiple rows can be marked by holding the Ctrl key. A continuous selection can be made by holding the Shift key and clicking on several row headers on the left side of the rows. All rows between the current cursor position and the clicked row are selected. Moving the cursor position in the attribute table, by clicking a cell in the table, does not change the row selection. Changing the selection in the main canvas does not move the cursor position in the attribute table.

The table can be sorted by any column, by clicking on the column header. A small arrow indicates the sort order (downward pointing means descending values from the top row down, upward pointing means ascending values from the top row down).

For a simple search by attributes on only one column, choose the Column filter ‣ from the menu in the bottom left corner. Select the field (column) on which the search should be performed from the drop-down menu, and hit the [Apply] button. Then, only the matching features are shown in the attribute table.

To make a selection, you have to use the ^{Select features using an Expression} icon on top of the attribute table. ^{Select features using an Expression} allows you to define a subset of a table using a Function List like in the ^{Field Calculator} (see フィールド計算機). The query result can then be saved as a new vector layer. For example, if you want to find regions that are boroughs from regions.shp of the QGIS sample data, you have to open the Fields and Values menu and choose the field that you want to query. Double-click the field ‘TYPE_2’ and also [Load all unique values] . From the list, choose and double-click ‘Borough’. In the Expression field, the following query appears:

"TYPE_2"  =  'Borough'

Here you can also use the Function list ‣ Recent (Selection) to make a selection that you used before. The expression builder remembers the last 20 used expressions.

The matching rows will be selected, and the total number of matching rows will appear in the title bar of the attribute table, as well as in the status bar of the main window. For searches that display only selected features on the map, use the Query Builder described in section クエリビルダー.

選択されたレコードのみを表示したい場合右下のメニューの Show Selected Features を利用して下さい.

属性テーブルの上部にあるその他のボタンは以下のような機能を提供しています:

• ^{編集モードの切替} 単一の値を編集して以下の機能を利用可能にします( Ctrl+E でも実行可能 )

• ^{編集の保存} ( Ctrl+S でも実行可能 )

• ^{全選択解除} ( Ctrl+U でも実行可能 )

• ^{選択を先頭に移動} ( Ctrl+T でも実行可能 )

• ^{選択部分の反転} ( Ctrl+R でも実行可能 )

• ^{選択している行をクリップボードにコピー} ( Ctrl+C でも実行可能 )

• ^{選択行の地物に地図をズームする} ( Ctrl+J でも実行可能 )

• ^{選択行の地物に地図をパンする} ( Ctrl+P でも実行可能 )

• ^{選択地物の削除} ( Ctrl+D でも実行可能 )

• ^{新規カラム} PostGIS レイヤまたはGDAL version >= 1.6の場合の OGRレイヤ用 ( Ctrl+W でも実行可能 )

• ^{カラムの削除} PostGIS レイヤまたはGDAL version >= 1.9の場合のOGR レイヤ用 ( Ctrl+L でも実行可能 )

• ^{フィールド計算機を開く} ( Ctrl+I でも実行可能 )

選択地物を新規レイヤに保存する¶

The selected features can be saved as any OGR-supported vector format and also transformed into another coordinate reference system (CRS). Just open the right mouse menu of the layer and click on Save selection as ‣ to define the name of the output file, its format and CRS (see section 地図凡例). It is also possible to specify OGR creation options within the dialog.

新しいレイヤへのペースト¶

Features that are on the clipboard may be pasted into a new layer. To do this, first make a layer editable. Select some features, copy them to the clipboard, and then paste them into a new layer using Edit ‣ Paste Features as and choosing New vector layer or New memory layer.

これは QGIS で選択しコピーされた地物に対し、またはwell-known text (WKT)を使って定義された他のソース由来の地物に対して適用されます。

空間的でない属性テーブルの作業¶

QGIS では空間情報が無いテーブルをロードすることができます. この機能は OGRでサポートされているテーブルや, デリミテッドテキストと同じように PostgreSQL, MSSQL とOracle プロバイダで利用できます. テーブルに対してフィールドのルックアップや一般的な閲覧,編集をテーブルビューで行うことができます. テーブルをロードすると凡例フィールドに表示されます. これはたとえば ^{Open Attribute Table} ツールで開くことができ他の属性テーブルと同じように編集できます.

As an example, you can use columns of the non-spatial table to define attribute values, or a range of values that are allowed, to be added to a specific vector layer during digitizing. Have a closer look at the edit widget in section フィールドメニュー to find out more.

外部キー¶

Then you get another point layer or table with information about airports that are located in the regions and you also want to keep track of these. If you want to add them to the region layer, you need to create a one to many relation using foreign keys, because there are several airports in most regions.

Figure Relations 1:

Alaska 領域の空港

In addition to the already existing attributes in the airports attribute table another field fk_region which acts as a foreign key (if you have a database, you will probably want to define a constraint on it).

This field fk_region will always contain an id of a region. It can be seen like a pointer to the region it belongs to. And you can design a custom edit form for the editing and QGIS takes care about the setup. It works with different providers (so you can also use it with shape and csv files) and all you have to do is to tell QGIS the relations between your tables.

レイヤ¶

QGIS makes no difference between a table and a vector layer. Basically, a vector layer is a table with a geometry. So can add your table as a vector layer. To demostrate you can load the ‘region’ shapefile (with geometries) and the ‘airport’ csv table (without geometries) and a foreign key (fk_region) to the layer region. This means, that each airport belongs to exactly one region while each region can have any number of airports (a typical one to many relation).

定義（リレーションマネージャー）¶

最初に行うべきことは QGIS にレイヤ間のリレーションを教えることです. それは 設定 ‣ プロジェクトプロパティ でできます. リレーション メニューを開いて 追加 をクリックして下さい.

• 名称 はタイトルとして使われます. これは人間が読んでわかり文字列にするべきです, そしてこのリレーションがどういう意味なのかわかるような文字にするべきです. 今回のサンプルでは “Airports” とします.

• 参照レイヤ とは外部キーフィールドを持つレイヤです. 私たちの例では airports レイヤです

• 参照フィールド とは他のレイヤとリンクするフィールドです 私たちの例では　fk_region です

• 参照先レイヤ とはプライマリキーでリンクするレイヤです,私たちの例ではregions レイヤになります

• 参照先フィールド は参照先レイヤのプライマリキーです,今回の例では ID です

• id は内部の用途で使われます,この値はユニークでなければいけません. これがサポートされる場合カスタムフォームをサポートする必要があります. もしここを空白にしていた場合自動的に生成されますが,扱いやすいものがある場合自分で設定することもできます.

Figure Relations 2:

リレーションマネージャ

フォーム¶

Now that QGIS knows about the relation, it will be used to improve the forms it generates. As we did not change the default form method (autogenerated) it will just add a new widget in our form. So let’s select the layer region in the legend and use the identify tool. Depending on your settings, the form might open directly or you will have to choose to open it in the identification dialog under actions.

Figure Relations 3:

airports のリレーションを表示した地物特定ダイアログ

As you can see, the airports assigned to this particular region are all shown in a table. And there are also some buttons available. Let’s review them shortly

• The button is for toggling the edit mode. Be aware that it toggles the edit mode of the airport layer, although we are in the feature form of a feature from the region layer. But the table is representing features of the airport layer.
• The button will add a new feature to the airport layer. And it will assign the new airport to the current region by default.
• The button will delete the selected airport permanently.
• The symbol will open a new dialog where you can select any existing airport which will then be assigned to the current region. This may be handy if you created the airport on the wrong region by accident.
• The symbol will unlink the selected airport from the current region, leaving them unassigned (the foreign key is set to NULL) effectively.
• The two buttons to the right switch between table view and form view where the later let’s you view all the airports in their respective form.

If you work on the airport table, a new widget type is available which lets you embed the feature form of the referenced region on the feature form of the airports. It can be used when you open the layer properties of the airports table, switch to the Fields menu and change the widget type of the foreign key field ‘fk_region’ to Relation Reference.

If you look at the feature dialog now, you will see, that the form of the region is embedded inside the airports form and will even have a combobox, which allows you to assign the current airport to another region.

Figure Relations 4:

Identification dialog airport with relation to regions