If you are creating a new query in the SQL Statement Design screen, the default properties for the query are set for a SELECT query that will return all rows meeting the search criteria.
However, you can use the SQL Statement Design screen to select a different query type or to select different options for the query. The options for a SELECT query are different from the options for an INSERT, UPDATE, or DELETE query.
The SQL Statement Design screen supports the following query types:
SELECT query – returns data from the table or tables you specify. It does not modify the contents of the tables.
A SELECT query can return all rows that meet your criteria. Alternately, you can choose to return only the unique values from a column, and you can choose to return only the top n values or the top n% of the values from a column.
INSERT query – inserts new records into the table you specify.
UPDATE query – modifies existing records in the table you specify.
DELETE query – deletes existing records from the table you specify.
Caution: Executing INSERT, UPDATE, and DELETE queries will modify the contents of your table – and in most cases, a simple method to undo the changes does not exist. If you must use one of these query types, use extra caution when building the SQL statement. Before testing or executing a new INSERT, UPDATE or DELETE query, make sure that you have a recent backup of the affected table and that you know how to restore the table from backup if necessary. |
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