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WDB Help on Queries

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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.

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

Exp.Start....... :

These are the operands that are available for querying in the fields.
<
Less than.
>
Greater than.
<=
Less than or equal to.
>=
Greater than or equal to.
!=
Not equal to.
!~
Not like (with wild-cards, i.e. !~ G* (translated to: not like "G%")
=
Equal to (with wild-cards, i.e. the * operator)
~
As = but ignoring case.
==
Exact match (No wild-cards)
*
Wild-card in strings ( A*B will match AB, AxB, AxxxxB, etc. ).
..
A range of values (ex.: 234.56 .. 678.9 ).
|
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 has a fixed set of allowable values from which you can choose.
Instrument...... :
These fields normally have a default value of "ALL" 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 :

[Help] [Home]

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 "Exp.Start" 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 Prop Dataset Name      Exp.Start        Inst    Target Name 
MORE 3545    W1460G01T 28 Sep 92 04:29:18    WFPC      53W045A
MORE 3545    W1460G02T 28 Sep 92 06:05:18    WFPC      53W045A
MORE 3545    W1460G03T 28 Sep 92 07:41:18    WFPC      53W045A
MORE 3545    W1460G04T 28 Sep 92 09:18:18    WFPC      53W045A
MORE 3545    W1460H01T 28 Sep 92 12:31:18    WFPC      53W045A
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.
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 would 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 Ctrl key and the left mouse button at the same time (in Mosaic). Try it now !

Other options

At the end 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, and you can adjust the maximum number of rows to return at a time.
Use full-screen output even if more than one row is returned.
Return max rows.
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Last modified: Aug 1 2007