WDB Help on Queries

WDB is an interface between the World Wide Web and relational databases. This document gives you some hints on how to specify query constraints in WDB. For information about WDB in general take a look at the WDB User Manual.

Specifying Query Constraints.
Submitting Your Query
Tabular Output
Controlling Tabular Output
Other options

Specifying Query Constraints.

When you first enter a WDB query form you will see a lot of query fields like this :

Date Obs....... :
These are the operands that are available for querying in the fields:

= Equal to (with wild-cards, i.e. the * operator) < Less than.

== Exact match (No wild-cards) > Greater than.

!= Not equal to. <= Less than or equal to.

!~ Not like (with wild-cards, i.e. !~ G* (translated to: not like "G%") >= Greater than or equal to.

* Wild-card in strings ( A*B will match AB, AxB, AxxxxB, etc. ). .. A range of values (ex.: 234.56 .. 678.9 ).

~ As = but ignoring case. | OR Will match any of the specified expressions (ex.: =123 OR > 5000 OR < 1 ).
So for example : To select all exposures that started between the first of January and the fifth of February you could enter :

Exp.Start.. :

When you search in text fields, without specifying an operator it will be interpreted as '~*your-text*'

Some fields have a fixed set of allowable values from which you can choose.
Instrument...... :
These fields normally have a default value of "Any" which means : Accept all values in this field.

Submitting Your Query

To get the result of your query you have to submit it. At the top and at the bottom of the query form you will see a set of buttons like this :

In order to to submit your request press the "Search" button. If you want to reset all the fields back to the way they where before you started entering qualifiers in them, press the "reset" button. (You could try to edit the "Date Obs" field above and then press the "Reset" button).

Tabular Output

If you submit a query that returns more than one row of data, you will a list in tabular form like this :

More HDR      OBJECT      Target RA,DEC         Program_ID      Instrument  MJD_OBS         Dataset_ID
 Header    HD_93204  10:44:31.80 -59:44:31.0 0102.D-0234(D)  PIONIER   58492.329082277   PIONI.2019-01-09T07:53:52.709
 Header    HD_93204  10:44:31.80 -59:44:31.0 0102.D-0234(D)  PIONIER   58492.330406805   PIONI.2019-01-09T07:55:47.148

There will typically be one or more columns where the values have hypertext links. The values in the leftmost column will normally lead you to a full-screen version of the corresponding row, with all information available. Other columns will lead you to related data screens.
If the column header contains a link, that can be used to get to its specific documentation.
Try it out !

Controlling Tabular Output

The tabular output will normally only display a sub-set of the columns available. However you are able to change the selection of which columns should be displayed.

Each field in the query form are prepended with a toggle field, which indicates whether the field should be included in tabular output or not. This toggle is not selected, so the corresponding field would not be included in the tabular output. This toggle is selected so the corresponding field will be included in the tabular output.

Sometimes additional fields can be chosen from a selection box under the query fields. This would look like this :
Extra columns on tabular output :
Several fields can be selected using the Shift key and the left mouse button at the same time. Try it now !

Other options

At the bottom and at the top of the query form there are a few additional options that you can change if you need to. You can force WDB to use the full-screen output format even if your query returns more than one row; you can adjust the maximum number of rows to return at a time; depending on the query form, you might be able to change the output format (default: html); etcetera.
Examples:
Use full-screen output even if more than one row is returned.
Return max rows.

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Last modified: Jul 24 2025

`=`	Equal to (with wild-cards, i.e. the * operator)	`<`	Less than.
`==`	Exact match (No wild-cards)	`>`	Greater than.
`!=`	Not equal to.	`<=`	Less than or equal to.
`!~`	Not like (with wild-cards, i.e. !~ G* (translated to: `not like "G%"`)	`>=`	Greater than or equal to.
`*`	Wild-card in strings ( A*B will match AB, AxB, AxxxxB, etc. ).	`..`	A range of values (ex.: 234.56 .. 678.9 ).
`~`	As `=` but ignoring case.	`\| OR`	Will match any of the specified expressions (ex.: =123 OR > 5000 OR < 1 ).