Support Tables

The set of linked database tables. By definition, all database tables for a given Project must share the same Project Support tables (STATIONS, PCODES, etc.). The support tables are:

• STATIONS - station descriptions
  

• BRANCHES - branch descriptions
  
• PCODES - parameter code descriptions
  
• CCODES - compositing code descriptions
  
• RCODES - result codes to quality numeric results (e.g., <, >, etc.)
  
• QCODES - quality codes assigned to tables
  
• STAGRP - station groups
  
• PCODEGRP - parameter code groups
  
• CONVGRP - conversion groups
  
• FIPSCODES - static table created for you which identifies states and counties
  
• VALIDATION - contains miscellaneous validation entries (sets of valid values for selected fields)
  
• CRITERIA - water quality criteria overrides
  
• WQXMETHODS - specialty tables required to upload data to EPA STORET via WQX (advanced feature)
  
• TRACKING - tracking information for data batches
  
• JOURNAL - log of all editing operations on tables (new in Version 6.0)

Support tables are automatically created when you create your Project, and can be maintained using Support Table Browsers. Careful management of Support tables is crucial to successful project management. When using WRDB for the first time, you will probably want to make some key decisions before beginning:

• Station IDs: IDs can be up to 25 characters in length. You may wish to use preexisting agency IDs where available, and a custom identification scheme for non-public stations like TR1234 for "Tributary station 1234" and WI26 for "Withdrawal station 26". Other schemes might help you to remember station locations such as FLINT_DS for "Flint River downstream station". A careful consideration of ID assignments that is extensible will save you headaches in the future.

• PCodes: if you intend to acquire most of your data from a single source, you will probably want to adopt the parameter code (PCode) scheme employed there (e.g., 00300 = Dissolved oxygen). PCodes can be up to 10 characters in length. You can also use mnemonic codes such as "DO". It will be important to be consistent though. For example, if data from three sources use 00300, 300, and DO for their dissolved oxygen pcode, you will probably want to convert imported data to all use the same PCode that you adopt. This allows you to perform queries like "SELECT FOR PCODE='DO'" rather than "SELECT FOR PCODE='DO' OR PCODE='00300' OR PCODE='300'". PCode conversion can be done on the fly during import (see Data Conversion Overview and Convert Records).

• CCodes: Compositing Codes can be used to further qualify the type of data you have; a three-character-max value can be assigned to each observation. CCodes commonly are used to identify grab versus composite, daily average versus instantaneous, and/or measured versus modelled.

The PCode and CCode schemes can probably be used for multiple projects. If you have an existing project which already contains a full set of codes, you can reuse the information (see Set Up Support Tables).