GUI Query Builder - Columns Tab

Access this window by clicking on the Columns tab of the Query Builder.

With this window you can:

• add or remove columns from the query

  You can do this by checking / unchecking columns in the panel on the left, or with the New or Del buttons.

  Use Mod to modify a query column in the Build Query Column dialog.

• change the order of the columns in the query

  This is done with the Move Up or Move Down buttons.

• specify a column function.

  Select one from the drop-down list, or enter a function. The column name will be substituted where you have a colon.

• give your columns a Display Name.

  This is the name of the column when the query is run.

  Use a : where you want the column name included.

• specify the order-by columns for the table. These give the order in which rows will be returned by the query.

  Click on Order By to select the column as a order-by-column. If you have multiple columns, they will be selected in the order you click them. Right-click Order By to decrease the columns order-by position. Click on the Delete button to not sort by this column.

  Click Asc/Desc to toggle between sort ascending and sort descending.

• Show specifies whether this column will be displayed.

  You may have some columns which you need to have in your order-by list, but do not wish to include in the query. For these, de-select Show.

• specify a simple Where clause (search condition) for the query.

  This is done with Where Op and Where Value.

  You can also specify Where conditions on the Where tab. This provides a more fully-featured method for building Where clauses.

Specifying Literals

You may want your query to return a literal value or system variable. Examples: 23, 'Unknown', CURRENT DATE, USER.

To do this, specify this literal value in the Function field. Because the value does not contain a colon, no column name will be added.

Alternatively, you can click on New or Mod to go to the Build Query Column dialog.

Adding a column to a query multiple times

Sometimes you may want to have a column in your query multiple times - for instance with a different function for each appearance. Example:

Select DATE(Update_Time), TIME(Update_Time) From Table

You can do this by clicking on New to create a new query column. When you use this, you can create multiple query columns using the same table column.

Summary Query

When this is checked, this specifies that you are building a Summary Query.

This is discussed in Summary or Group-by Query.

Other Features

Distinct

Use this option to display only distinct rows in your query. Duplicate rows will be removed. This option is generally not of much use if you are displaying all columns in the table. It is often used to display the different values a column can take. In this case you will specify only one or two columns in the query.

All

Use this option to specify the ALL option for your query. This option is the default so there should be no need to specify it.

Types

When this is checked, the column types will be displayed in the grid.

Desc

When this is checked the column description will be displayed in the grid..