Update delete query

We are going to use the film and language table of the sakila database. The syntax is the following:. Suppose the UPDATE statement encounters an error that was raised due to unique constraint duplicate value error or data conversion errors.

Execute the following query to view the current values of the rating column. Suppose we want to change the replacement cost from To change the values, execute the following query to view the current data. STC Admin June 10, Share This Post. Share on facebook. Share on linkedin. Share on twitter.

Share on email. Popular Tutorial Series. Browse to and point to select the database, click the arrow next to the Open button, and then click Open Exclusive. Access closes the original file, creates a backup, and then reopens the original file. Click Save As and specify a name and location for the backup copy, and click Save.

Note: If you are using a read-only or a database created in the previous version of Access, you might get a message that it is not possible to create a back-up of the database. To revert to a backup, close and rename the original file so that the backup copy can use the name of the original version. Assign the name of the original version to the backup copy, and open the renamed backup copy in Access. To create a delete query, click the Create tab, in the Queries group, click Query Design.

Double-click each table from which you want to delete records, and then click Close. The table appears as a window in the upper section of the query design grid. Important: Use criteria to return only the records that you want to delete.

Otherwise, the delete query removes every record in the table. Double-click the field that you want to specify as the criteria for deletion, enter one the criteria in the Criteria row of the query designer, and then clear the Show check box for each criteria field. An example of when you might want to use this option: Suppose you want to remove all of the pending orders for a customer.

Note: You cannot use the update query option in an Access web app. This section explains how to use an update query to delete individual fields from tables. Remember that running an update query to delete data will change the existing values to either NULL or a zero-length string a pair of double quotation marks with no space in between , depending on the criteria that you specify.

Click the Create tab and in the Queries group, click Query Design. Select the table which has the data you want to delete if the table is related, select the table on the "one" side of the relationship , click Add , and then click Close.

The window lists all of the fields in the selected table. Adding all the table fields enables the delete query to remove entire records rows from the table. Optionally, you can enter criteria for one or more fields in the Criteria row of the designer, and then clear the Show check box for each criteria field.

For more information about using criteria, see the Sample criteria for select queries table. Note: You use criteria to return only the records that you want to change.

Otherwise, the update query sets to NULL every record in each of the fields in your query. Verify that the query returns the records that you want to set to NULL or a zero-length string a pair of double-quotation marks with no space between them "". If you want to delete data from several related tables, you must enable the Referential Integrity and Cascade Delete Related Records options for each relationship. This allows your query to delete data from the tables on the "one" and "many" sides of the relationship.

Preparing to deleted related data requires verification of the following:. Determine which records reside on the "one" side of the relationship and which reside on the "many" side. If you need to delete records on the "one" side of the relationship and the related records on the "many" side, you enable a set of rules called Referential Integrity, and you enable cascading deletes. Steps in this section explain Referential Integrity, and how to perform both tasks.

If you need to delete records only on the "one" side of the relationship, you first delete that relationship, and then delete the data. If you need to remove data only on the "many" side of the relationship, you can create and run your delete query without having to change the relationship. This transaction must fully completed or fully cancelled and not to fail halfway. Note: The above 5 resolutions are options for how do you want to resolve the conflict. It may not be necessarily what is applicable to resolve one conflict is applicable to resolve other types of conflicts.

Using the following syntax:. However, SQLite continues executing other statements after that row. Skip to content. Report a Bug.