# Edit a Query Mapping [](https://help.qlik.com/talend/en-US/talend-data-catalog/Content/user-guide/data-mapping/edit-a-query-mapping.htm) When defining a query mapping, the target classifier may come from any data store model defined in the configuration limited to the **Model scope** for the **DESTINATION**. Sources too may come from any data store model(s) limited to the **Model scope** for the **SOURCE**, and as you may have many source classifiers, they could come from multiple source models in the same mapping. In addition to defining mapping specifications, the data mapping allows you to define all the physical data integration constructs, including joins, filters, transformation operations, etc., which may even be forward engineered into data integration tools. **Steps** Ensure proper permissions 1. Sign in as a user with at least the **Metadata Editing** [capability object role assignment](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/administration-and-system-management/manage-object-roles.htm) on the Data Mapping you are going to edit. Navigate to the mapping to edit 1. [Navigate](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/explore/index.htm) to the [object page](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/analyze/object-page.htm) for the data mapping model and navigate to the folder if necessary. 2. Click the **Query Mappings** tab. 3. [Create](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/create-a-data-mapping.htm) the query mapping (if necessary). 4. Click to open the query mapping. 5. Click **START EDITING.** Assign the source(s) 1. Click **+ Add Source** to include a source table. 2. Specify as many source tables as needed. 3. Specify a filter to narrow down the features to choose from: * All * Mapped * Unmapped. Map Using the Target Panel 1. Click the **Detect Links** magic wand to automatically match tables and columns. 2. Click the **Joins** tab to edit joins. 3. Click the **Detect Joins** magic want to automatically define joins for the source tables. 4. Click the **Filter** tab to edit filters. 5. Click the **Order By** tab to edit the order of the data movement. 6. Click the **Group By** tab to edit the grouping in the data movement. 7. Edit the **Operation** for a target column, including using the functions editor. Map Using Both Panels 1. Drag a specific source column to target column to map all the columns. 2. Drag another source column into an already mapped target column to include the new column in the existing mapping and operation. Information note Additional columns will be appended with a plus sign ("+") in the operation. Thus, invalid operations could result which must be corrected. Other 1. Expand the **Details** panel to see details (overview tab from the object page) for any selected object. 2. Click **Save**. Information note You may click on the search in the header of either the source or target side to locate specific columns/fields. **Example** Add Sources Click the query mapping (**VendorPayment**) to open it. Click **START EDITING**. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image995.png) Click **+ Add Source**. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image996.png) In the **Browse** tab, pick the **Adj** and **AdjType** tables. Click **OK**. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image997.png) Define Joins Click the **Joins** tab. Click the **Detect Joins** magic wand. Click **OK** to accept the suggestion. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image998.png) Define Filters Click the **Filters** tab. Drag **AdjTyp** to the expression. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image999.png) Type > = "VV" in the expression. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1000.png) Information note TDC validates the expression as you type, thus, the line disappears until you have a valid expression (finish the last single quote mark). You may also click go to the **Details** tab on the left and look at the **Profiling** information for information about what values are valid, the data types, etc. Define mappings Click the **Columns** tab. Search for the PaymentAmount column by entering > payment into the search box in the top right of the **Target** panel: ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1001.png) Drag the **Adj**.**TransAmt** column to the **PaymentAmount** column. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1002.png) Select both the **Adj**.**AdjTyp** and **Adj**.**AdjTxt** columns and drag them to the **PaymentDescription** column. Click on the expression and expand the Functions panel at the bottom right. Information note You may also click the **Adj**.**AdjTyp** column and drag it first, then click the **Adj**.**AdjTxt** column and drag it into the same target and you would obtain the same result. Click the target column. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1003.png) Information note In order to read longer **Descriptions** and **Operations**, you may resize the column headers and thus the column contents. Expand the **Functions** panel on the lower right, select **String** and then double-click on **CONCAT**. Edit the expression to be "`CONCAT(Adj.AdjTxt, Adj.AdjTyp)`". ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1004.png) Information note Again, the mapping lines disappear while the expression is invalid and only reappear when the expression is complete and valid. Click on the **Operation** next to **CheckNumber**. Enter > "Adjustment" in the expression text below. ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1005.png) Information note Fixed values. In this case the value > Adjustment are allowed also. Click **Save**. Complex Expressions You may also simply type in complex expressions, such as **CASE**. Enter the following for the **PaymentAmount** Operation: CASE Adj.AdjTyp WHEN "01" THEN Adj.TransAmt WHEN "02" THEN -Adj.TransAmt ELSE Adj.TransAmt END ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1006.png) Other Functions You may also enter other functions, even if they are not in the pick list. Select **Preferences > Unknown functions**. Enter the following for the **PaymentAmount** **Operation** CONCAT2(Adj.TransSetNm, CONCAT(Adj.AdjNum, Adj.TransDT)) ![](https://help.qlik.com/talend/en-US/talend-data-catalog/Cloud/Content/user-guide/data-mapping/img/image1007.png) Information note There is a warning about the unknown function, but Save is still enabled, and lineage is still produced.