UPDATE, DELETE, and INSERT Statements

SQL-based applications make changes to tables by executing the UPDATE, DELETE, and INSERT statements. These statements are part of the Minimum SQL grammar conformance level and must be supported by all drivers and data sources.

The syntax of these statements is:

UPDATE table-name
SET column-identifier = {expression | NULL}
[, column-identifier = {expression | NULL}]...
[WHERE search-condition]

DELETE FROM table-name [WHERE search-condition]

INSERT INTO table-name [(column-identifier [, column-identifier]...)]
{query-specification | VALUES (insert-value [, insert-value]...)}

Note that the query-specification element is valid only in the Core and Extended SQL grammars, and that the expression and search-condition elements become more complex in the Core and Extended SQL grammars.

Like other SQL statements, UPDATE, DELETE, and INSERT statements are often more efficient when they use parameters. For example, the following statement can be prepared and repeatedly executed to insert multiple rows in the Orders table:

INSERT INTO Orders (PartID, Description, Price) VALUES (?, ?, ?)

This efficiency can be increased by passing arrays of parameter values. For more information about statement parameters and arrays of parameter values, see “Statement Parameters” in Chapter 9, “Executing Statements.”