How to get a value from the last inserted row?
JavaDatabasePostgresqlJdbcJava Problem Overview
Is there some way to get a value from the last inserted row?
I am inserting a row where the PK will automatically increase, and I would like to get this PK. Only the PK is guaranteed to be unique in the table.
I am using Java with a JDBC and PostgreSQL.
Java Solutions
Solution 1 - Java
With PostgreSQL you can do it via the RETURNING keyword:
INSERT INTO mytable( field_1, field_2,... )
VALUES ( value_1, value_2 ) RETURNING anyfield
It will return the value of "anyfield". "anyfield" may be a sequence or not.
To use it with JDBC, do:
ResultSet rs = statement.executeQuery("INSERT ... RETURNING ID");
rs.next();
rs.getInt(1);
Solution 2 - Java
See the API docs for java.sql.Statement.
Basically, when you call executeUpdate()
or executeQuery()
, use the Statement.RETURN_GENERATED_KEYS
constant. You can then call getGeneratedKeys
to get the auto-generated keys of all rows created by that execution. (Assuming your JDBC driver provides it.)
It goes something along the lines of this:
Statement stmt = conn.createStatement();
stmt.execute(sql, Statement.RETURN_GENERATED_KEYS);
ResultSet keyset = stmt.getGeneratedKeys();
Solution 3 - Java
If you're using JDBC 3.0, then you can get the value of the PK as soon as you inserted it.
Here's an article that talks about how : https://www.ibm.com/developerworks/java/library/j-jdbcnew/
Statement stmt = conn.createStatement();
// Obtain the generated key that results from the query.
stmt.executeUpdate("INSERT INTO authors " +
"(first_name, last_name) " +
"VALUES ('George', 'Orwell')",
Statement.RETURN_GENERATED_KEYS);
ResultSet rs = stmt.getGeneratedKeys();
if ( rs.next() ) {
// Retrieve the auto generated key(s).
int key = rs.getInt(1);
}
Solution 4 - Java
Since PostgreSQL JDBC driver version 8.4-701 the PreparedStatement#getGeneratedKeys()
is finally fully functional. We use it here almost one year in production to our full satisfaction.
In "plain JDBC" the PreparedStatement
needs to be created as follows to make it to return the keys:
statement = connection.prepareStatement(SQL, Statement.RETURN_GENERATED_KEYS);
You can download the current JDBC driver version here (which is at the moment still 8.4-701).
Solution 5 - Java
The sequences in postgresql are transaction safe. So you can use the
currval(sequence)
> currval > > >Return the value most recently obtained by nextval for this sequence > in the current session. (An error is > reported if nextval has never been > called for this sequence in this > session.) Notice that because this is > returning a session-local value, it > gives a predictable answer even if > other sessions are executing nextval > meanwhile.
Solution 6 - Java
Here is how I solved it, based on the answers here:
Connection conn = ConnectToDB(); //ConnectToDB establishes a connection to the database.
String sql = "INSERT INTO \"TableName\"" +
"(\"Column1\", \"Column2\",\"Column3\",\"Column4\")" +
"VALUES ('value1',value2, 'value3', 'value4') RETURNING
\"TableName\".\"TableId\"";
PreparedStatement prpState = conn.prepareStatement(sql);
ResultSet rs = prpState.executeQuery();
if(rs.next()){
System.out.println(rs.getInt(1));
}
Solution 7 - Java
If you are using Statement
, go for the following
//MY_NUMBER is the column name in the database
String generatedColumns[] = {"MY_NUMBER"};
Statement stmt = conn.createStatement();
//String sql holds the insert query
stmt.executeUpdate(sql, generatedColumns);
ResultSet rs = stmt.getGeneratedKeys();
// The generated id
if(rs.next())
long key = rs.getLong(1);
If you are using PreparedStatement
, go for the following
String generatedColumns[] = {"MY_NUMBER"};
PreparedStatement pstmt = conn.prepareStatement(sql,generatedColumns);
pstmt.setString(1, "qwerty");
pstmt.execute();
ResultSet rs = pstmt.getGeneratedKeys();
if(rs.next())
long key = rs.getLong(1);
Solution 8 - Java
Use sequences in postgres for id columns:
INSERT mytable(myid) VALUES (nextval('MySequence'));
SELECT currval('MySequence');
currval will return the current value of the sequence in the same session.
(In MS SQL, you would use @@identity or SCOPE_IDENTITY())
Solution 9 - Java
PreparedStatement stmt = getConnection(PROJECTDB + 2)
.prepareStatement("INSERT INTO fonts (font_size) VALUES(?) RETURNING fonts.*");
stmt.setString(1, "986");
ResultSet res = stmt.executeQuery();
while (res.next()) {
System.out.println("Generated key: " + res.getLong(1));
System.out.println("Generated key: " + res.getInt(2));
System.out.println("Generated key: " + res.getInt(3));
}
stmt.close();
Solution 10 - Java
Don't use SELECT currval('MySequence') - the value gets incremented on inserts that fail.
Solution 11 - Java
For MyBatis 3.0.4 with Annotations and Postgresql driver 9.0-801.jdbc4 you define an interface method in your Mapper like
public interface ObjectiveMapper {
@Select("insert into objectives" +
" (code,title,description) values" +
" (#{code}, #{title}, #{description}) returning id")
int insert(Objective anObjective);
Note that @Select is used instead of @Insert.
Solution 12 - Java
for example:
Connection conn = null; PreparedStatement sth = null; ResultSet rs =null; try { conn = delegate.getConnection(); sth = conn.prepareStatement(INSERT_SQL); sth.setString(1, pais.getNombre()); sth.executeUpdate(); rs=sth.getGeneratedKeys(); if(rs.next()){ Integer id = (Integer) rs.getInt(1); pais.setId(id); } }
with ,Statement.RETURN_GENERATED_KEYS);"
no found.
Solution 13 - Java
Use that simple code:
// Do your insert code
myDataBase.execSQL("INSERT INTO TABLE_NAME (FIELD_NAME1,FIELD_NAME2,...)VALUES (VALUE1,VALUE2,...)");
// Use the sqlite function "last_insert_rowid"
Cursor last_id_inserted = yourBD.rawQuery("SELECT last_insert_rowid()", null);
// Retrieve data from cursor.
last_id_inserted.moveToFirst(); // Don't forget that!
ultimo_id = last_id_inserted.getLong(0); // For Java, the result is returned on Long type (64)
Solution 14 - Java
If you are in a transaction you can use SELECT lastval()
after an insert to get the last generated id.