The Query tool is a powerful, feature-rich environment that allows you to execute arbitrary SQL commands and review the result set. If you access the Query tool via the *Query Tool* menu option on the *Tools* menu, you can:
* The upper panel of the Query tool contains the *SQL Editor*. You can use the panel to manually enter a query, or review the query that generated the result set displayed in the lower panel.
* The lower panel of the Query tool contains the *Data Output* panel. The output panel displays the result of a query, or information about a query's execution plan.
pgAdmin allows you to open multiple copies of the Query tool (in individual tabs) simultaneously. For example, if you select *Query tool* from the *Tools* menu, the Query tool opens in a tab labeled *Query-1*; if you open the Query tool again (without closing *Query-1*), a second copy will open in *Query-2*. To close a copy of the Query tool, click the *X* in the upper-right hand corner of the tab bar.
**The Query tool Toolbar**
The *Query tool* toolbar uses context-sensitive icons that provide shortcuts to frequently performed tasks. If an icon is highlighted, the option is enabled; if the icon is grayed-out, the task is disabled.
The *SQL editor* panel contains a workspace for entering commands; you can read a query from a file, or type a query. The SQL editor features syntax coloring and autocompletion to help you develop queries.
To use autocomplete, begin typing your query; when you would like the Query editor to suggest object names or commands that might be next in your query, press the Control+Space key combination. For example, type "\*SELECT \* FROM\* " (without quotes, but with a trailing space), and then press the Control+Space key combination to select from a popup menu of autocomplete options.
After entering a query, select the *Execute/Refresh* icon from the toolbar. The complete contents of the SQL editor panel will be sent to the database server for execution. To execute only a section of the code that is displayed in the SQL editor, highlight the text that you want the server to execute, and click the *Execute/Refresh* icon:
The message returned by the server when a command executes is displayed on the *Messages* tab of the output panel. If the command is successful, the *Messages* tab displays execution details:
The editor also offers several features that help with code formatting:
* The auto-indent feature will automatically indent text to the same depth as the previous line when you press the Return key.
* Block indent text by selecting two or more lines and pressing the Tab key.
* Block outdent text that has been indented using the Shift+Tab key combination.
* Comment out SQL by selecting some text and pressing Control+K.
* Uncomment SQL by selecting some text starting with a comment and pressing Control+Shift+K.
* Shift the selected text to upper case by pressing Control+U.
* Shift the selected text to lower case by pressing Control+Shift+U.
**The Data Output Panel**
Use the *Data Output* panel of the *Query tool* to view data and information generated by a query in the *SQL editor*, or to *View Data* for an object currently selected in the *pgAdmin* tree control.
The *Data Output* panel organizes output through the following tabs: *Data Output*, *Explain*, *Messages*, and *History*.
If the Query tool is opened through the *Query tool* menu option on the *Tools* menu, you can use the *Data Output* tab to view the results of an arbitrary query in a table format. If the Query tool is opened through a *View Data* context menu, the *Data Output* tab will display the data stored in the table from which the Query tool was opened.
All rowsets from previous queries or commands that are displayed in the *Data Output* panel will be discarded when you invoke another query; open another query tool browser tab to keep your previous results available.
If the Query Tool is opened using the *View Data* menu option and the data is updatable and has a primary key, then you can double-click on values on the *Data Output* tab and edit them:
* To enter a NULL, clear the value of the string.
* To enter a blank set the value of the cell to ''.
* To enter the string ''. enter the value \'\'.
Once the data has been edited as required, use the Save button to save the changes to the database.
To generate a graphical explain diagram, open the *Explain* tab, and select *Explain*, *Explain Analyze*, or one or more options from the *Explain options* menu on the *Execute/Refresh* drop-down. Please note that *EXPLAIN VERBOSE* cannot be displayed graphically. Hover over an icon on the *Explain* tab to review information about that item; a popup window will display information about the selected object:
If the server returns an error, the error message will be displayed on the *Messages* tab, and the syntax that cause the error will be underlined in the SQL editor.
