16.12.2020

Return Auto Generated Key Queryjdbc Mysql Java

97

JDBC's auto-generated keys feature provides a way to retrieve valuesfrom columns that are part of an index or have a default value assigned. Derby supports the auto-incrementfeature, which allows users to create columns in tables for which the databasesystem automatically assigns increasing integer values. Users can call the method Statement.getGeneratedKeysto retrieve the value of such a column. This method returns a ResultSet objectwith a column for the automatically generated key. Calling ResultSet.getMetaData onthe ResultSet object returned by getGeneratedKeys produces a ResultSetMetaData objectthat is similar to that returned by IDENTITY_VAL_LOCAL.

Crypto key generate cisco 3750. Users can indicate that auto-generated columns should be made availablefor retrieval by passing one of the following values as a second argumentto the Connection.prepareStatement, Statement.execute, or Statement.executeUpdate methods:

This example shows how to retrieve auto generated primary key by the database (via an insert statement). Following method of JdbcTemplate takes KeyHolder argument which will contain the generated key on the successful insert execution. Return generated keys: SQL Update « Database SQL JDBC « Java. Java; Database SQL JDBC; SQL Update.

  • A constant indicating that auto-generated keys should be made available. The specific constant to use is Statement.RETURN_GENERATED_KEYS.
  • An array of the names of the columns in the inserted row that should be made available. If any column name in the array does not designatean auto-increment column, Derby will throw an error with the Derby embeddeddriver. With the client driver, the one element column name is ignored currently and the value returned corresponds to the identity column. To ensure compatibility with future changes an application should ensure the column described is the identity column. If the column name corresponds to another column or a non-existent column then future changes may result in a value for a different column being returned or an exception being thrown.
  • An array of the positions of the columns in the inserted row that shouldbe made available. If any column position in the array does not correlate to an auto-increment column, Derby willthrow an error with the Derby embeddeddriver. With the client driver, the one element position array is ignored currently and the value returned corresponds to the identity column. To ensure compatibility with future changes an application should ensure the column described is the identity column. If the position corresponds to another column or a non-existent column then future changes may result in a value for a different column being returned or an exception being thrown.

Example

Assume that we have a table TABLE1 definedas follows:

The following three code fragments will all do the same thing:that is, they will create a ResultSet that contains the value of C12 that is inserted into TABLE1.

Auto

Return Auto Generated Key Query Jdbc Mysql Java System

Code fragment 1:

Return Auto Generated Key Queryjdbc Mysql Java Pdf

Code fragment 2:

Return Auto Generated Key Query Jdbc Mysql Java Download

Code fragment 3:

Return Auto Generated Key Query Jdbc Mysql Java Software

If there is no indication that auto-generated columns shouldbe made available for retrieval, a call to Statement.getGeneratedKeys will return a null ResultSet.