Difference between revisions of "UPDATE"
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==Example== | ==Example== | ||
<code lang="recital"> | <code lang="recital"> | ||
| − | select | + | select b |
| + | use newpatrons alias new | ||
| + | select a | ||
| + | use patrons index names, events, dates | ||
| + | update on name from new; | ||
replace balance with balance + new->balance | replace balance with balance + new->balance | ||
</code> | </code> | ||
Revision as of 10:32, 16 March 2009
Contents
UPDATE
Class
Fields and Records
Purpose
Update the contents of the active table with data from another table
Syntax
UPDATE ON <key expression> FROM <workarea | alias>
REPLACE <field> WITH <exp> [,<field> WITH <exp>...]
[RANDOM]
See Also
AVERAGE, COUNT, SUM, TOTAL, SET FILTER, SET RELATION
Description
The UPDATE command updates fields in the active table based upon data from another table. The <key expression> must exist in both tables. The active table must be indexed on the specified <key expression> unless the RANDOM keyword is specified. The FROM table can be in any order. If a FILTER <condition> is active in the FROM workarea, then only those records which satisfy the <condition> are processed. If SET DELETED is ON, then records which are marked for deletion in the FROM workarea are not processed.
It is strongly recommended that the active table be indexed on the <key expression>, otherwise ALL records satisfying the <key expression> values in the FROM file are updated in the active table, which can be a lengthy process. The UPDATE command is primarily used to update a 'master' file from records held in a 'transaction' file.
Example
select b use newpatrons alias new select a use patrons index names, events, dates update on name from new; replace balance with balance + new->balance
Products
Recital Database Server, Recital Mirage Server, Recital Terminal Developer
