我正在尝试对结果集进行更新,并且我得到了一个具有主键的表上的 No primary key found for table nvp,
。
是PostgreSQL 9.6.1.0,JDBC驱动程序版本是PostgreSql-9.4.1212.Jar从其网站下载(JDBC42 PostgreSQL驱动程序,版本9.4.1212,此处)。
> >@Test
public void testUpdateableResultSet() throws Exception {
String url = "jdbc:postgresql://localhost:5432/dot";
Properties props = new Properties();
props.setProperty("user", "dot_test");
props.setProperty("password", "test_dot");
props.setProperty("currentSchema", "dot_test");
try(Connection conn = DriverManager.getConnection(url, props)) {
conn.setAutoCommit(false);
try(Statement s = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE)) {
s.execute("drop table if exists nvp");
s.execute("create table nvp (id int primary key, value text);");
s.execute("insert into nvp (id, value) values (1, 'one_'), (2, 'two_')");
}
try(PreparedStatement ps = conn.prepareStatement("select value from nvp",
ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
ResultSet rs = ps.executeQuery()) {
while(rs.next()) {
String s = rs.getString(1);
if(s.endsWith("_")) {
s = s.replace("_", "");
}
else {
s = s + "_";
}
rs.updateString(1, s); // line 28
System.out.println("row updated");
}
}
}
}
以下结果。
Testcase: testUpdateableResultSet(com.tekbot.lib.sql.SimpleTest): Caused an ERROR
No primary key found for table nvp.
org.postgresql.util.PSQLException: No primary key found for table nvp.
at org.postgresql.jdbc.PgResultSet.isUpdateable(PgResultSet.java:1586)
at org.postgresql.jdbc.PgResultSet.checkUpdateable(PgResultSet.java:2722)
at org.postgresql.jdbc.PgResultSet.updateValue(PgResultSet.java:3056)
at org.postgresql.jdbc.PgResultSet.updateString(PgResultSet.java:1393)
at com.tekbot.lib.sql.SimpleTest.testUpdateableResultSet(SimpleTest.java:28)
这是一个错误吗?我错过了一步吗?
必须指定主键,以便结果集可更新
将line 17
上的查询更改为:
PreparedStatement ps = conn.prepareStatement("select id, value from nvp"...