first commit for openGauss connector jdbc

docs/documentation/93/update.md

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+---
+layout: default_docs
+title: Performing Updates
+header: Chapter 5. Issuing a Query and Processing the Result
+resource: media
+previoustitle: Using the ResultSet Interface
+previous: resultset.html
+nexttitle: Creating and Modifying Database Objects
+next: ddl.html
+---
+
+To change data (perform an `INSERT`, `UPDATE`, or `DELETE`) you use the
+`executeUpdate()` method. This method is similar to the method `executeQuery()`
+used to issue a `SELECT` statement, but it doesn't return a `ResultSet`; instead
+it returns the number of rows affected by the `INSERT`, `UPDATE`, or `DELETE`
+statement. [Example 5.3, “Deleting Rows in JDBC”](update.html#delete-example)
+illustrates the usage.
+
+<a name="delete-example"></a>
+**Example 5.3. Deleting Rows in JDBC**
+
+This example will issue a simple `DELETE` statement and print out the number of
+rows deleted.
+
+`int foovalue = 500;`  
+`PreparedStatement st = conn.prepareStatement("DELETE FROM mytable WHERE columnfoo = ?");`  
+`st.setInt(1, foovalue);`  
+`int rowsDeleted = st.executeUpdate();`
+`System.out.println(rowsDeleted + " rows deleted");`
+`st.close();`